Dear Dr. Resnick,

I am 50 years old and have been very healthy except I have a type of arthritis that is treated with a medicine that suppresses my immune system.  I have become alarmed about the measles outbreaks here in California where I live since people like me are more vulnerable to all infectious diseases. I had to ask my GP to check to see if I were still immune to measles and he reluctantly did a blood test called MMR, which documented that I was still immune.  However, one of the members of my support group found out that she was not immune ( though she had been checked years before). She did get the vaccination.  I have three questions:
1.  Why do people who had measles when they were young or had the infection, lose their immunity to measles?
2.  Shouldn’t everyone be tested again for MMR and be immunized again if they are no longer immune?
3.  How bad could this public health crisis become since so many people are no longer having recommended vaccinations?  

Sara

Dear Sara,

Many people born prior to the 1960s remember having measles. One patient described it to me as “the sickest I have ever been.”  Measles is a highly contagious viral illness that causes high fevers and a rash. The disease can have serious complications including pneumonia and swelling of the brain (encephalitis) that may cause disability or even death.  Prior to the availability of the measles vaccine, there were approximately 500,000 reported cases of measles in the United States each year, but the real number of infections may have been closer to four million. Approximately 48,000 people were hospitalized, 1,000 were permanently disabled, and 500 died each year.  After 1967, the measles vaccine was widely available and cases in the U.S. declined by more than 99%, culminating in 2000 when measles was declared eradicated here.

The measles vaccine, given as part of the measles, mumps, and rubella or “MMR” combination vaccine, is extremely safe and effective. Children now routinely receive two doses of the vaccine, which results in 99% of those who receive the vaccine becoming immune. Rarely, one may not respond to the vaccine or may lose immunity over time; however, we are not sure why some people lose their immunity over time and others keep strong immunity.  This has not been a significant issue since most people were fully vaccinated and cases of the disease were extremely rare. When the disease was eradicated, even those who were not immune were not at risk of exposure to the disease.

Unfortunately, a fraudulent medical study was published in 1998 that claimed that the MMR vaccine was linked to Autism Spectrum Disorder and gastrointestinal disease.  This “research” was resoundingly proven to be false; the “study” was commissioned and funded by a group seeking to file a class-action lawsuit against vaccine manufacturers. The authors blatantly falsified the data, the journal that published the study retracted it, and the lead author had his medical credentials revoked.  Devastatingly, the damage was done, and some parents seized on this lie as a reason not to vaccinate their children. The anti-vaccine movement has grown rapidly, fueled by an internet frenzy and irresponsible rhetoric, and represents possibly the most harmful fraud in modern medicine. Decreased vaccination rates due to vaccine refusal led to an increase in measles cases, which occurred almost exclusively in unvaccinated people.  For example, over the ten years between 2001-2010, there were only 692 measles cases reported in the U.S., and there have already been more than 700 cases reported in the first four months of 2019. We have no idea how widely this current outbreak will spread, but we do know that the vast majority of those who have contracted measles were not fully vaccinated. The scientific fact is that vaccines are safe, effective, and save lives; not just the lives of those who receive vaccines but of those around them who may be unknowingly susceptible.

The resurgence of this once eradicated disease means that people who have lost their immunity over time, as well as those who cannot be vaccinated because they take immunosuppressive medications, are on chemotherapy, or are pregnant are now at risk of contracting this deadly disease.  Due to the current outbreak, it is a good idea for every adult born after 1959 (those born before 1959 are assumed to have been exposed to measles) to make sure they are still immune to measles, which can be done through a simple blood test. If there is no evidence of measles antibodies one should receive an MMR booster shot to become protected.  In rare cases, there are specific health conditions that prevent one from being vaccinated, so please discuss your case with your doctor.

References

Health impact of measles vaccination in the United States.
Bloch AB, Orenstein WA, Stetler HC, Wassilak SG, Amler RW, Bart KJ, Kirby CD, Hinman AR Pediatrics. 1985;76(4):524.

Epidemiology of measles–United States, 2001-2003.
Centers for Disease Control and Prevention (CDC)
MMWR Morb Mortal Wkly Rep. 2004;53(31):713.

Epidemiology and Prevention of Vaccine-Preventable Diseases (The Pink Book), 12th ed, Atkinson W, Wolfe C, Hamborsky J (Eds), The Public Health Foundation, Washington, DC 2011.

How the case against the MMR vaccine was fixed.
Deer B BMJ. 2011;342:c5347