Measles: Immune Amnesia and Susceptibility to Infectious Diseases

Measles is an extremely contagious disease — on average, 90% of those exposed to the virus become infected, unless they’ve been vaccinated, or have already contracted and resolved the infection. The virus spreads from person to person, is airborne, and hangs around up to two hours — in the air and on surfaces — after the infected individual that coughed or sneezed leaves the area.

T lymohocyte

T lymphocyte. Image credit: NIAID, CC BY 2.0

Although there is no treatment or cure for measles, most people who catch it do survive the infection. However, measles is not a harmless childhood disease — it can, indeed, cause lifelong disabilities, or even kill. Severe complications include, among others, ear infections that can lead to hearing loss, pneumonia, and encephalitis. According to the CDC, for every 1,000 children who get measles, one or two will die from it.

The major cause of death in infants infected with the measles virus is immunosuppression — the virus suppresses the function of the immune system, making it unable to fight other infectious diseases. More specifically, the virus wipes out immunological memory the ability of the immune system to remember previous encounters with infectious microorganisms and respond to them more rapidly and effectively.

Since its introduction in the 1960s, mass measles vaccination has reduced childhood mortality by 30 to 50% in resource-poor countries, and by up to 90% in the most impoverished populations. Such dramatic declines in mortality cannot be explained only on the basis of the vaccine ability to prevent primary measles virus infections alone — instead, it could be an indirect effect. By preventing measles infection, the vaccine may also prevent the loss of immunological memory, and thus prevent secondary infections and complications.

Now, results from a new study show that children infected with the measles virus remain vulnerable to other potentially deadly infections up to three years after clearing measles. Lead author Michael Mina said he was motivated to carry out his study because of previously published research showing that the measles virus attacks memory lymphocytes — lymphocytes responsible for immunological memory. By attacking these memory lymphocytes, measles leads to immune amnesia — the immune system no longer remembers previous encounters with pathogens.

C. Jessica Metcalf, one of the researchers involved in the new study, said: “We already knew that measles attacks immune memory, and that it was immunosuppressive for a short amount of time. But this paper suggests that immune suppression lasts much longer than previously suspected. In other words, if you get measles, three years down the road, you could die from something that you would not die from had you not been infected with measles.”

Researchers examined measles cases and death rates from other infectious diseases before and after widespread measles vaccination in the United States, England and Wales, and Denmark. They found that the number of measles cases in a given period of time correlates with the number of deaths caused by non-measles infectious diseases during the following two to three years.

Mina told Nicholas Bakalar (New York Times): “With mathematical analysis of all of the epidemiological evidence we have, it seems that when measles was prevalent, it would go through a population, and that population would be at increased risk for mortality from other diseases for about 28 months, and in proportion to how many people were infected with measles.”

However, due to the design of the study, the researchers could not prove a cause-and-effect relationship — indeed, their results only identified a link between measles infection and increased risk of other infectious diseases. Even so, the study results are intriguing, and provide a convincing explanation for the ability of measles vaccination to prevent infectious diseases caused by many other infectious pathogens.

29 comments

  1. This study provides the most compelling reason yet for measles vaccination. Faster and stronger secondary response of the immune system stops most pathogens before we even know they are inside us, and is dependent on immediate activation of pathogen-specific antibodies already present in our bodies and the actions of B and T memory cells. The findings from this new study are chilling; the fact that measles does not just cause immediate severe infection, but predisposes the patient to more than three years of immunosuppression and immune amnesia for many other pathogens (not just measles), should prompt universal vaccination.

    Yet there is a growing movement of parents who refuse to vaccinate their children, citing studies linking vaccines to autism – despite the fact that these studies have been discredited as fraudulent. According to the World Health Organization, roughly 15% of the world’s population is still unvaccinated (http://www.who.int/gho/immunization/measles/en/). As some of this percentage consists of people who are too young to be vaccinated or are in some way already immunocompromised (and therefore ineligible for the vaccine), it makes it that much more important for everyone who CAN be vaccinated to do so, to improve herd immunity. Herd immunity affords a greater level of protection to those among us who are most vulnerable to disease, but it only works if the vast majority of the population has been vaccinated.

    The Centers for Disease Control has confirmed 189 measles cases so far this year, with an outbreak of 113 cases traced to Disney theme parks in California in March. The majority of these individuals were unvaccinated (http://www.cdc.gov/measles/cases-outbreaks.html). This leads to the erosion of herd immunity and the return of diseases previously controlled, if not completely eradicated. This outbreak led the California legislature to pass a bill mandating vaccinations for all children in public schools and daycares. The only exception granted would be if a physician confirmed the vaccination would endanger the student’s health. The bill was signed into law on 6/30/15 (http://leginfo.legislature.ca.gov/faces/billHistoryClient.xhtml?bill_id=201520160SB277). U.S. Congresswoman Frederica Wilson (D-FL-24) sponsored a similar bill that would cut funding to all public schools that did not mandate vaccination of all non-medically exempted students (H.R.2232-Vaccinate All Children Act of 2015). (https://www.congress.gov/bill/114th-congress/house-bill/2232/text). Given the importance of preserving herd immunity, and the fact that disease transmission readily crosses state boundaries with impunity, this bill deserves passage.

    • Trisha, I agree with you on one point. This study does provide a most compelling reason to receive the MEASLES VACCINATION. As a parent, I am “pro measles vaccination.” But in my household we are pro and anti vaccination. And it is not about autism. The measles vaccination is given in a syringe that also contains vaccinations for mumps, rubella, and chicken pox. What are the common serious dangers of the other diseases? There are none. At most, the common symptom among them all is general discomfort. Symptoms, commonality, and severity of all can be found on the CDC website. The immune system works perfectly fine to fight those viral infections, and then you gather the same immunity you would from a vaccination. Yes your body had to work hard for that immunity, but that is the entire purpose of the immune system. Unnecessary vaccines and the over distribution of antibiotics are the main components of the “wussification of the immune system.”

      Works cited:
      http://www.cdc.gov/vaccines/vpd-vac/default.htm

  2. As a scientist, the points brought up by the study about how measles wipes out memory effector cells leaving an individual weak to the infection of common pathogens make sense. However, while these explanations make perfect sense to me, there are still large groups of people, commonly known as “anti-vaxxers”, that still do not believe in the benefits of immunization. Some refrain from the practice because of cultural or religious practices, while other are adamant that these vaccines lead to development problems such as autism; a theory, it should be noted, has been disproved time and time again. The fact of the matter is that the practice of immunization should not be viewed as a personal or familiar preference, but more as a global interaction.

    As we saw with the recent measles outbreak in Disneyland, the lack of vaccine practices of one group adversely affected several people who either had children too young to receive the MMR vaccine or were immunosuppressed and therefore susceptible to all types of infections. While the study mentioned could not find a concrete link between the infection of measles and the increase of other infections later in life other than the death of immune memory cells, it should always be remembered that every immunization has its benefits. An immune system trained to deal with several different pathogens is more likely to create faster response to new infections. On the whole, vaccinating every person that can be vaccinated creates a “herd protection” which in turn will protect all of those individuals who cannot receive immunization because of legitimate medical reasons. And in doing so, reduces the cost of healthcare in a population, diminishing the wealth gap in less developed countries between those that can afford medication and those who cannot.

    In conclusion, many people who claim that vaccination is “against nature” or “causes unwanted effects” should educate themselves about the science behind the practice. They are tried and tested formulations made with the utmost care in order to bring forth the benefit of protecting against a certain disease. Moreover, if your concern against immunization is the health of your family, consider that a bout of measles, although may be treated with medication can lead to an infection that might have been non-fatal to wreak havoc on the system of a loved one and kill them. There is no grace or poetry in dying from the flu when there are measures that can be taken to 1) prevent the infection from a deadly pathogen, and 2) conserve the immune system you have spent all your life building up to protect you from infection. You cannot claim a practice is unnatural while risking the health of your family and everyone they may come in contact with.

    • That’s a great point Jennifer. Anti-vaxxers are not just endangering themselves, but they are endangering others. The idea that vaccines lead to autism has been debunked many times, and yet people continue to put themselves and their children in danger.

      Immune amnesia is a horrifying effect of measles, and it underlies the importance of getting the MMR vaccine. Immune amnesia will make others more susceptible to diseases that should never affect adults, like chicken pox, tetanus, and hepatitis B. However, all these dangerous infections can be prevented by simply receiving the MMR vaccine. By ignoring common sense, anti-vaxxers put society in danger.

  3. The World Health Organization (WHO) claims measles as one of the leading causes of death among young children, that is, even with the vaccine. There were 114,900 deaths as a result of measles just recently, in 2014. The measles vaccination causes a 79% decrease in deaths, due to measles, between 2000 and 2014. So, my question is, why aren’t we ALL getting this safe and cost-effective vaccine.

    The virus is airborne and can be passed by direct contact, lasting up to 2 hours after the infected source has exited. The fact that this virus can remain contagious for such a long period after the subject is no longer present is reason to believe in the power thereof. Measles can cause an enormous amount of damage to the immune system, causing its functionality to suffer.

    In an article I read, the immune suppression follows a mechanism where the T-cell responds initially, including CD8 and T-helper 1 CD4 T cells, however, the RNA from the virus persists resulting in a transition to a response from T-helper 2 CD4 T-cells, promoting the maturation of B-cells and antibody responses, but likely suppressing macrophage activation and T-helper 1 responses to new infections. Other cells, such as, lymphocytes, and dendritic cells, are susceptible to the infection and dendrite cells can transmit the infection to lymphocytes, in which, measles virus infected dendrite cells are not able to stimulate a lymphocyte reaction, inducing lymphocyte unresponsiveness. (Griffin, 2010)

    Understanding the effects of measles virus on a cellular level explains how the body is at a great risk for later infections. The virus cause permanent damage to some of the most vital immune cells, therefore, they cannot carry out their normal functions properly. I am convinced that the measles virus does more than just momentary damage, but it can be the underlying cause of a death years later.

    Works Cited
    Griffin, D.E. “Measles virus-induced suppression of immune responses .” Immunological Reviews 236.1 (2010): 176-189.
    Measles. November 2015. .

    • There is this continuous debate over the use of vaccinations in general. But when one sees the significant effects of the measles virus on our health, it becomes imperative for us to be vaccinated to be immune in order for our immune system to fight off the virus when infection does occur. Studies over the years continue to show the indirect correlation of the measles virus to the mortality rate in children. So yes, “why aren’t we all getting this safe vaccine?” An interesting aspect to this is that there is reduced childhood mortality in impoverished/underdeveloped/developing countries. Take for example, countries like India and China, which have a significant rise in populations. Personally having lived in India and Brazil, I know first-hand that a large population is not even accounted for when studies release statistics over percent of children infected with the virus. So the prevalence of the measles virus may actually be even higher than what some studies show, I would think. Not only are people not being vaccinated (due to its costs, unavailability, or simply unawareness), but since the virus is airborne, I would think a higher percent of the populations of these countries would be getting affected. Now this is an issue since the virus is airborne and a potential global concern. The unavailability or high costs for people who cannot afford it, makes it impossible to control the infection in these populations. Another important aspect to this is the ability of the measles virus to weaken the health of the affected person to the point that he or she is vulnerable to other infections. Considering the serious implications of losing memory of previous pathogens makes us vulnerable to even the slightest of microbes. So yes, I agree! It is better that we get vaccinated and as for its effectiveness? A recent study showed that there was no relationship between MMR vaccines and children’s cognitive development. I think it, therefore, makes it imperative that we all be vaccinated on time in order to avoid any further health complications and a possible strategic plan in underdeveloped populations to control the high rise in infection.

      Mrozek-Budzyn D, Kiełtyka A, Majewska R, Augustyniak M. Measles, mumps and rubella (MMR) vaccination has no effect on cognitive development in children – the results of the Polish prospective cohort study. Vaccine. 2013 May 24;31(22):2551-7. doi: 10.1016/j.vaccine.2013.03.057. Epub 2013 Apr 12. PubMed PMID: 23588083; PubMed Central PMCID: PMC3684783.

  4. Measles is a serious disease in children caused by Measles virus with single stranded RNA as genetic material. The virus first settle down in lung tissue of the host where they start infecting macrophages and dendritic cells. The dendritic cells pick up the antigen and travel to the nearest lymph node for further activation and proliferation of B cells and T cells. The dendritic cells play a very important role in immune response by bridging the gap between innate and adaptive immune response, but dendritic cells when infected by the virus expresses Measles virus glycoprotein and become unable to initiate the lymphocyte proliferation and activation.
    During this processing, a surface protein called CD150 on white blood cells acts as a route of entry for the viruses. Thus infected immune cells spread the virus through blood in the body. In very rare case the virus can cross blood brain barrier causing inflammation in the brain. http://news.sciencemag.org/health/2015/01/what-does-measles-actually-do

    According to researchers in 2012, monkeys who were infected with this virus recovered by producing new B cells and T cells a month after the infection. And, the new cells only had memory for the measles virus not for other infections that the monkeys had encountered previously. This amnesia of immune system makes those monkey vulnerable to infections that otherwise may not have a problem. http://blogs.discovermagazine.com/d-brief/2015/05/07/measles-immune-system/#.VkvaUXarSM8
    Measles virus induced immune suppression, include loss of delayed type hypersensitivity responses and increased susceptibility to secondary infections. http://jvi.asm.org/content/72/12/9421.full

    Reference:

    Schneider-Schaulies S, Klagge IM, ter Meulen V. Dendritic cells and measles virus infection. Curr Top Microbiol Immunol. 2003;276:77-101. Review. PubMed
    PMID: 12797444.

    • The study that involved the monkeys is a reassurance that the measles virus will interrupt the already developed memory of the immune system. Measles is a very serious virus and the vaccine is of great importance. As seen in the monkeys, the new B and T cells that were produced after the measles infection only had memory for the measles, putting the monkeys at a greater risk of being infected by other “already encountered” pathogens. This is a scary disease, attacking the immune response, causing immune suppression. Even if the body wins the fight against this vicious virus, it will still have the challenge of numerous other infections.

  5. Vaccines have time and time again been proven to be valuable tools in protecting the lives and the quality of life of multiple generations, and they will likely continue to do so as society moves forward in to the future. While minimal, my concern with vaccines stems not from the medical application, which has been proven effective with little to no risk to a patients overall health, but from the involvement of bureaucracy. A large part of the patient/clinician relationship revolves around trust, and the understanding that the clinician wants what is in the patient’s best interest. Vaccines or the requirement of use of vaccines can open some dark doors regarding this relationship, beginning with a Pakistani doctor that was arrested and sentenced after he was found to be completing DNA testing under the guise of polio vaccinations (http://www.washingtontimes.com/news/2014/mar/15/imprisoned-pakistani-doctor-who-helped-cia-track-b/). This was done at the request of the CIA, a US bureaucratic institution. While this may be an extremely polarized example in which the physician helped capture one of the world’s most dangerous terrorists, the precedent stands that there could be risk for exploitation of this relationship.

    • Good point Zachary. There is an inherent risk of providing vaccination for any disease because there cannot always be surveillance of the people or establishments administering them. This trust can potentially be misused and cause the harming of many people. However, like most vaccines, especially the measles vaccine, I believe the pros heavily outweigh the cons in terms of its use. Measles is one of the few known infectious diseases that can absolutely wipe out immunological memory in people causing deaths from other infections or diseases that would never have occurred otherwise. This is attributed to the greatly reduced memory of T lymphocytes within the immune system. Thus, they are less equipped to respond in a specific pathogen targeting manner. In this regard, it is kind of like HIV which turns to AIDS, because carriers of the AIDS disease will often die of the most random and rare infectious agents. Measles erases memory(amnesia) of the immune system while HIV can lead to deficiency of the actual immune system. Consequently, it is very important that the measles vaccine is still used throughout the world in order to prevent the spread of extremely harmful disease.

    • But Zach, it is that very involvement by the government in vaccinations (through CDC public relations and education, imposing public school vaccination requirements and administration at community health centers) that not only increases compliance but controls the costs of the vaccinations, keeping them affordable. I agree with you completely that the patient-clinician relationship revolves around trust, but I don’t see mistrust of the clinician as being the issue with most parents that choose to not get their children vaccinated. The CIA operative posing as a physician is such an extreme example of governmental use of the practice of vaccination that it should rightly be relegated to consideration as a ludicrous exception, not the norm. It is (misguided) mistrust of the vaccines themselves, and the potential risks of illness they might cause, most often cited as justification for failure to vaccinate (although the psychological disconnect required to justify putting your child – and potentially everyone s/he interacts with – at risk for serious disease in order to “save” them from the almost nonexistent risk of the vaccine itself is something that I do not understand). While the CDC’s most recent data suggests a relatively high vaccination rate for the majority of younger children in the U.S. (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6433a1.htm), there is variance geographically and demographically, with some schools reporting much lower vaccination rates among students – especially those who attend private schools (http://usatoday30.usatoday.com/news/story/2012/09/9/private-school-vaccine-opt-outs-rise/57720458/1). Religious or personal-belief exemptions should simply not be allowed, as there is simply no way to protect the public from these potential walking time-bomb children.

      While there is a widely-held belief that the government’s price controls have turned most pharmaceutical companies away from vaccine production, a 2011 study by the National bureau of Economic Research disputed that hypothesis (http://www.nber.org/papers/w17205). Nevertheless, it is estimated that the top 5 vaccine manufacturers cornered 90% of vaccine sales (http://www.evaluategroup.com/public/EvaluatePharma-Overview.aspx), and the CDC buys approximately 50% of most vaccines (for public health distribution). With the advent of the development of vaccines for conditions like HPV and HIV, vaccine manufacturers are in a position to enjoy much greater profit margins than in past years. Without government involvement, those vital vaccines may very well be unaffordable to the average American.

    • For clarification, the physician responsible was in fact a physician that was bribed by the CIA, but I concede that point as being a hyperpolarized situation.

      While Jacobson v Commonwealth of Massachusetts has established that states do have the authority to require vaccinations when necessary to protect the community as a whole, my concern does not lie entirely with vaccinations as it does with government intervention. With the advent of genetic screening, multitudes of legislation have been required to insure there is no discrimination based on a person’s genotype, which most experts are still considering as incomplete. In combination the ability for states to require medical treatment for the greater good could set the precedent for the state’s ability to require genetic screening to assess for something such as H1N1 or any other infectious disease, and with the current provisions the Genetic Information Nondisclosure Act (GINA) provides, any patient exhibiting symptoms could have their genetic information legally disclosed within the parameters of GINA. The combination of the lack of protection provided by GINA and the precedent set forth by government mandated medical intervention could lead to significant exploitation of the patient.

      Rothstein, M. A. (2008), Currents in Contemporary Ethics. The Journal of Law, Medicine & Ethics, 36: 837–840. doi: 10.1111/j.1748-720X.2008.00341.x

    • It’s quite sad to know that a US bureaucratic institution such as the CIA is involved in bad clinical practice. It’ll make one to wonder how much more bad clinical practices they have been involved in. There has been several myths on mercury being found in vaccines. Thimerosal is a mercury preservative that has been discovered in several vaccines and it’s said to have no harmful evidence in low doses. Could this be another bad clinical practice? because there are outcries of its possible harmfulness. Whether or not Thimerosal is harmful, the government has to be completely honest in health related products like vaccines because human subjects are involved. They should also pay attention on long-term effects of vaccines and if there are adverse effects if certain drugs are taken.
      http://www.cdc.gov/vaccinesafety/concerns/thimerosal/

  6. Since the measles vaccine causes immunological amnesia due to killing off memory lymphocytes it would be wise for healthcare providers and scientist to recommend getting the measles vaccination first to prevent the virus from killing the memory lymphocytes that have been sensitized through vaccination against other pathogens. Then 3 years after the measles vaccine start vaccination against pathogens like hepatitis B virus, polio virus, rotavirus and tetanus. Vaccination for hepatitis B virus is given at birth but can wait because the virus is contracted through sexual contact, needle stick or through IV drug use (unless the mother has a history of hepatitis B virus). In addition, in the United States since polio has been for the most part irradiated vaccination can wait 3 years after the measles, mumps and rubella (MMR) vaccine. Also, the tetanus vaccination can be offered to the mother during pregnancy to provide immunological protection for the mother and the baby. Then after the measles vaccination pediatricians should test the blood to see if the baby still has antibodies to tetanus if levels are undetectable a booster should be given. If vaccination to measles can’t be done first, then 3 years after measles vaccination parents and pediatricians need to collect blood samples from the child to see if the child has antibodies to the vaccines given prior to measles vaccination. If the child has no antibodies against pathogens that were vaccinated against before measles then re-vaccination should be considered.

    • In severe cases of post-measles trauma, if the patient shows unexpected signs of illness or becomes hypogammaglobulinemic, infusions of protective antibodies can be given. This would ensure that the patient is able to fight common pathogenic assaults despite being immunocompromised.

    • Quite the contrary! The vaccine helps to prevent immune amnesia by preventing the full effects of the infection (Mina et al., 2015). Though it is a live vaccine the virus is attenuated and unable to efficiently enter cells or reproduce. This allows the body to create memory T and B lymphocytes without causing disease so it can quickly fight the virus off when encountered in the future (CDC, 2013). Due to the virus contained in the vaccine being attenuated, the introduction off the vaccine does not result in significant damage to the B and T lymphocytes or dendritic cells which the virus typically infects. As a result there is limited loss in memory B or T cells and therefore a prevention of immune amnesia (Mina et al., 2015).

      Mina, M. J., Metcalf, C. E., de Swart, R. L., Osterhaus, A. E., & Grenfell, B. T. (2015). Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality. Science (New York, N.Y.), 348(6235), 694-699.

      Understanding how vaccines work. (2013). CDC. Retrieved from http://www.cdc.gov/vaccines/hcp/patient-ed/conversations/downloads/vacsafe-understand-color-office.pdf

      de Vries, R. D., & de Swart, R. L. (2014). Measles Immune Suppression: Functional Impairment or Numbers Game?. Plos Pathogens, 10(12), 1-4.

  7. While current research has shown that measles infection does cause immune suppression it is quite surprising that this can last up to 3 years. As the virus preferentially infects both B and T lymphocytes, as well as dendritic cells, which express the CD150 receptor it is no wonder that infection would result in immune suppression. The “measles paradox” poses the question, however, on how immune suppression can last after viral clearance despite an increase in lymphocytes. A recent study hypothesized that this is likely due to the proliferation of measles virus specific lymphocytes while the decline results from lymphocytes found in secondary and tertiary lymphoid tissues (de Vries & de Swart, 2014). This fits with hypothesis proposed here.

    As there is a subset of the population currently refusing vaccination for their children it would be interesting to do a longitudinal study to verify the accuracy of these findings with actual clinical data in conjunction with their statistical findings. I would also be interested in the findings compared with 3rd world populations whose disease prevalence issues are quite different from our own.

    de Vries, R. D., & de Swart, R. L. (2014). Measles Immune Suppression: Functional Impairment or Numbers Game?. Plos Pathogens, 10(12), 1-4.

  8. Regarding the humoral immunity, the extent of protection provided by the vaccine depends directly on the antigen-specific antibody levels. Which in turn is dependent on the number and the life span of the terminally differentiated B cells: the plasma cells and the memory cells.

    According to the general consensus among scientists, it is believed that the antibody titers in the body are majorly maintained by continuous secretion of antibodies by the long-lived plasma cells in the bone marrow, whereas the memory cells produce antibodies intermittently depending on their reactivation by the antigen and their differentiation into new plasma cells.

    Hence, to be able to design an effective vaccination schedule and to ensure long-term protection against measles the kinetics of antibody titers, the extent of the role and life span of antigen-specific memory B cell and long-lived plasma cell populations need to be understood. The current debate on the contribution of memory B cells to the total antibody titers is far from reaching any conclusion.

  9. It is clearly known that measles is one of the most critical causes of child mortality in the world. Because of it’s ability to wipe out the immune system memory, most children die from a secondary infection. These young children are more vulnerable to late development of subacute sclerosing panencephalitis, a neurologic disease that is caused by persistent measles virus infection (MeV). The cute stages of the infection display a rash that characters the appearance of the adaptive immune response and CD8 T cell-mediated clearance of the virus. However after the infection is cleared, the MeV RNA can persist in the blood, respiratory secretions, urine, and lymphoid tissue. Studies show that the prolong process of virus clearance can help explain the immunosuppression that the measles causes and infection of the nervous system. The occurrence of MeV RNA persisting in the body after the disease has been cleared in unknown. The study read show that when the virus was replicated in cell cultures it cause cell death but in vivo there was persistence. It was more easily capable in neuronal cells and was also seen in the lymphoid, epithelial and glial cells. Such things as IFN-inducible proteins, heat-shock proteins, and altered regulation of lipid metabolism showed to help MeV establish and persistent in the body. The host and virus proteins both play apart in the persistence. Antibodies to MeV also show that they can play a role in their persistence. The alteration of the primary immune response at the initial infection and the virus entering the nervous system is proven to help with the persistence. There are many studies further trying to understand what is the specific target to help with immune suppression but this is why other disease start coming about such as sclerosis, Paget’s disease, or Crohn’s disease. None of the diseases are actually linked the MeV RNA but the persistence in the neuron cells and immune system are exactly why death is happening among these young children.
    Griffin, D. E., Lin, W., & Pan, C. (2012). Measles virus, immune control, and persistence. FEMS Microbiology Review

  10. As soon as I reflected on this article, the first thought in mind went to the implications of this article on “third world countries” where eliminating a disease from populations is more difficult. Most of these countries do not have sufficient access to vaccinations for all its citizens and established systems to distribute vaccination materials adequately. Also, there is a lot of miseducation and distrust about vaccinations in general. [1] “Third world countries” that are particularly prone to tropical diseases have high mortality rates associated with these diseases and increased difficulty of elimination when compared to “first world countries”. I focused on Sub-Saharan Africa when I evaluated the implications of immunosupression of measles. The article quoted that “for every 1000 children who get measles, one or two will die from it”. I couldn’t help but wonder if this statistic is referring to the US population or the world population. Nonetheless, it is inarguable that the mortality rate of such a disease would be higher in Sub-Saharan Africa than in the West. It was interesting to discover that a research article evaluating methods of mitigating the measles outbreaks in West Africa post-Ebola where the authors explained that the three countries affected by Ebola were planning measles vaccination campaigns right before Ebola struck. [1] This highlights the point made by Metcalf where she stated that if you get infected by measles, you may be at a higher risk of getting infected by another pathogen and at a higher risk of dying from it. It is not farfetched to assume that the measles outbreaks prior to the outbreak of ebola led to basically the opposite of herd immunity, where there was a decrease in immunity to a pathogen due to immunosuppression by a previous pathogen. I would have never thought that immunology and measles could have possibly been related to the Ebola outbreak in such a fascinating way prior to reading this article. This sheds light on a possible cause of the prevalence of epidemic and endemic diseases that is similar to the immunosuppression characteristic of measles; it is possible that diseases that appear in these countries function in cycles where one disease decreases immunosuppression that increases susceptibility to yet another tropical disease.

    Citation
    Truelove, S.A., W.J. Moss and J. Lessler. 2015. Mitigating measles outbreaks in West Africa post-Ebola. Expert Review of Anti-infective Therapy. 13: 1299 – 1301.
    website link: http://www.tandfonline.com/doi/full/10.1586/14787210.2015.1085305

  11. I grew up in Nigeria and measles was definitely a serious epidemic. Students who contacted it were isolated from the rest of the school. Fortunately I never contacted measles and don’t know someone who died directly from it. I always thought one contacted measles through physical contact with a measles patient. Finding out it could be contacted airborne makes me wonder why a lot more people didn’t get measles. Mass measles vaccination has reduced by 30-50% in resource-poor countries and by up to 90% in the most impoverished countries. In the United States within the past 15 years there has been an average of about 150 measles cases per year; highest being 383 in 2014. How is the U.S able to contain measles to this extent? Is this mainly to resource availability? Or does the environment also play a tole?
    What’s educating about this article is the mechanism through which measles attacks the immune system. Measles is said to cause immune amnesia meaning it wipes out immunological memory; the way the immune system remembers previously encountered microorganism and gets rid of them quickly. Measles vaccination can prevent immune amnesia which in turn prevents secondary infections. How long does measles induced immune amnesia last? Based on research one can gain immune memory after about a month. This makes me wonder if immune memory is being wiped out completely with no memory traces? Or does the measles virus turn off memory cells and the immune system gradually turn some or all back on?
    http://www.cdc.gov/measles/cases-outbreaks.html
    http://news.emory.edu/stories/2015/05/measles_mina_science/index.html

  12. I never knew measles could lead to immune amnesia, I’ve only heard amnesia in reference to the nervous system. After reading this and the blog post on neuro/immuno memory consolidation, I’m starting to see more similarities between the immune and nervous system. Although the long-term effects of the measles vaccine are not yet proven, I think the pros outweigh the cons. Losing all of your immunological memory would be terrible and expose you to other pathogens as well. In addition, I think this would negatively affect the immune system as a whole because it would be working harder to build up immunity.

    Personally, I don’t agree with the “anti-vaxers” but I do support doing more research. I work across at the CVS across the street from the CDC and the other month there was an anti-vaccination protest. I spoke to some of the protesters to see what their position was and if they had any supporting evidence. None of them seemed to be too educated on science or the immune system in general, but since I was at work I couldn’t say much. One of the protesters actually told me that the pharmacy was selling “poisonous flu shots”. While some people might not change their minds, we should still try to educate people about vaccinations in general.

    • Measles ability to wipe out the immune system memory can be very frightening for children because most of those children die from a secondary infection. Without an immune system, they are more vulnerable to any infection, especially a measles virus infection (MeV). Vaccines are very critical to protect our bodies from major infections such as measles or mumps or rubella. Certain vaccines in America are mandatory like the ones named but others like the yearly vaccine is not. When it comes to vaccines, I agree with you and also am a “pro-vaxer.” I completely believe we should get vaccinated against the major infections out there. Myself, I am vaccinated against the tuberculosis since I have lived in other countries. When a person is vaccinated they display more of a secondary adaptive response instead of a primary. Primary adaptive response does not recognize the infection versus a secondary adaptive response will have antibodies ready to protect the body. A person vaccinated will have the antibodies specific for that infection and block the infection from binding to cells and causing an immune response. A person not vaccinated has no antibodies to neutralize the infection and end up getting sick. What is ironic is that two days ago I read a story of a mother that failed to vaccinate her young child because of her beliefs. The story was written earlier in April. Later, one child caught whooping cough and the other 6 did also. She relied on the herd immunity in the community to protect them but because all 7 were not protected they all ended up being sick. She admits to the article that vaccination is the way to go. I have attached the article if anyone was interested in reading it.

      https://www.washingtonpost.com/news/to-your-health/wp/2015/04/14/anti-vax-mom-changes-her-tune-when-all-7-of-her-children-come-down-with-whooping-cough/

  13. This article surveys the ability of the Measles virus to inhibit the immunological memory of the immune system, thus leaving those suffering from the illness more vulnerable to immunosuppression, and thus complications from other diseases down the road. One aspect of this article that I found compelling was Measles’ ability to induce hearing loss, and in some cases even after the administration of a vaccination, thus representing a form of “immune amnesia”.

    The Rubella form of measles is a member of the Togaviridae family of viruses and is comprised of a single-stranded RNA. If Rubella, which is commonly referred to as German Measles, is obtained while a mother is pregnant, it can be a teratogen, which could have significant implications for the neurodevelopmental process of the child. Hearing loss is the manifestation of congenital rubella syndrome. While vestibular utility is spared, Sensiorneural Hearing Loss is the most frequent adverse manifestation of congenital rubella infection. There is a lot more research that needs to be conducted to understand the mode of action of Rubella created hearing loss, however it has been proven that the measles virus can induce direct cochlear damage and cell death in the Corti and Stria vascularis.

    Vaccination of women before arriving at reproductive age has proven to help prevent congenital rubella in their children. Additionally, the frequency of the formation of otosclerorsis is higher in those individuals who have never received a vaccination for measles then those who have. In places where people, especially women, are not routinely vaccinated, SNHL is a commonly observed condition. Contrarily, in some cases, congenital rubella still occurred even after vaccination. Whether this occurred as a result of a lapse in immunological memory is still not fully understood.

    While there is overwhelming evidence to prove that the measles vaccine provides sufficient coverage to protect children from the illness, more research should be conducted to discern under what conditions the vaccine may not work and why.

    Work Cited

    Cohen, Brandon E., Anne Durstenfeld, and Pamela C. Roehm. “Viral causes of hearing loss: a review for hearing health professionals.” Trends in hearing 18 (2014): 2331216514541361.

  14. While human implications are ultimately the goal of many research studies, it would be interesting to see how similar viruses effect animal models. For example, canine distemper virus (CDV) is of the same class of viruses that measles belongs to and studies have shown that the CDV can also cause immunosuppression. CDV is a highly contagious, systemic infection characterized by fever leukopenia, inflammation of the GI and respiratory membranes and can affect a variety of carnivore species. CDV quickly spreads throughout the immune system of carnivores and induces the two primary indicators of morbillivirus immunosuppression – inhibition of lymphocyte proliferation. Studying how CDV linked immunosuppression propagates in carnivore species could have many implications. In Indonesia, an increasing number of Sumatran tigers – a critically endangered species – are being exposed to CDV. This is likely not the only highly endangered species at risk of CDV. With increasing numbers of species becoming endangered or extinct, this path of study could increase conservation efforts around the globe. This could also have implications in zoological settings as well. Since CDV is air borne, it can spread easily from one individual to another. If multiple animals or carnivore species are kept in close quarters, then the risk of infection is high

    http://jvi.asm.org/content/77/23/12579.short
    http://jvi.asm.org/content/86/7/3658.abstract
    http://www.merckvetmanual.com/mvm/generalized_conditions/canine_distemper/overview_of_canine_distemper.html
    http://news.nationalgeographic.com/news/2013/06/130612-canine-distemper-virus-health-tigers-science-animals/

  15. I believe this article emphasizes the unique threat of viruses such as measles that pose a threat so strong against our immune systems and it is primarily due to indirect effects. Most known viruses directly attack the immune system and disease incurred was as a direct result of its infection. The ability to erase immune memory through destruction of memory lymphocytes cannot be understated and failure to see this as a major issue could be devastating for future generations. Victims of immune suppression from measles are known to experience life-threatening illnesses that would have been controlled if not for prior measles infection. How do we know that future measles virus strains will not evolve to diversify in not only the types but intensity of infections that develop? Could these rare infections be spreadable to the point where even people that were vaccinated with measles still get infected? These critical questions are the reasons why I feel maximizing measles vaccination must be the primary goal globally in terms of reducing the chances for the virus to evolve into a form that is much stronger in its indirect effects and also one that could be more deadly in its direct form as well.
    Studies and research confirms that is the number one preventer of death within children in terms of its vaccine usage. The virus can not only degrade lymphocyte memory but also can debilitate the ability of cells like dendrites to present antigens and activate what would be additional memory T cells to help support the immune system. These effects are responsible for the “erasing” and “amnesia” that measles causes, thereby facilitating the entry of previously non-threatening microbes. These microbes in turn now have become quite potent due to a weakened system and wreak havoc especially in the less developed systems of children or aged systems of the elderly. This article illustrates why its vaccination must be used globally to prevent unthinkable infection outbreak in the future.

    Kerdiles, Y., Sellin, C., Druelle, J., & Horvat, B. (2005). Immunosuppression caused by measles virus: Role of viral proteins. Rev. Med. Virol. Reviews in Medical Virology, 16(1), 49-63. doi:10.1002/rmv.486

  16. Measles is an incredibly dangerous disease that is easily prevented by the MMR (measles, mumps, and rubella) vaccine. Despite this, measles outbreaks are still reported in countries like India. Measles remains a leading cause of death in young children. Recent efforts by the Indian government, in collaboration with the World Health Organization (WHO), have taken place to try to prevent mortality due to measles.

    It’s sad that the ones who are succumbing to measles are those in resource poor countries. Impoverished populations are the ones who are affected by the symptoms of measles, like pneumonia, encephalitis, and immune amnesia, the most.

    In 2010, India’s efforts to reduce their measles burden have improved the lives of thousands of children. For example, the number of cases in Gujarat has gone from 1000 in 2010 to zero in 2012.

    The measles vaccine is actually incredibly cheap. It costs less than a dollar to vaccinate a child against measles. By increasing awareness of this global problem, we can eradicate measles as we did smallpox, and improve the livelihood of the poor.

    Sources:
    UNICEF’s website: http://unicef.in/Story/1000/Measles
    World Health Organization’s website: http://www.who.int/features/2013/india_measles/en/

    • I agree, since the measles vaccine is incredibly cheap, there is absolutely no reason as to why this disease is still prominent in countries like India. I understand that the World Health Organization has made in effort to eradicate the measles virus, however, I feel like more can be done.

  17. Measles is a virus that is highly contagious given that the virus is an airborne pathogen that can spread from person to person via cough or sneeze. It was the first virus identified to cause immunosuppression in the host, dampening the immune response, and making an individual susceptible to diseases that would normally be resolved. Fortunately, researchers have created vaccination capable of preventing primary infections. However, there is a part of society that does not agree with vaccinations, even though it has proven to be effective in preventing disease. According to this blog, “Mass measles vaccination has reduced childhood mortality by 30 to 50% in resource-poor countries, and by up to 90% in the most impoverished populations.” Given that some individuals cannot have vaccinations for certain health reasons, I feel that it is our responsibility for the people that can receive vaccinations to do so, to protect the individuals who cannot, especially since some viruses are more dangerous towards infants and children.

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