MMR Vaccine Shows Potential for Protection Against COVID-19

A new study has theorized that the MMR vaccine could provide potential protection against, as well as reduce the severity, of the coronavirus disease 2019 (COVID-19). The theory behind the study was first put forth in March of 2020, after observations that countries with the fewest COVID-19 deaths had recent, large scale MMR vaccination campaigns.

The study, published in mBio, shows that the levels of mumps IgG antibodies are inversely correlated with the level of severity in COVID-19 patients who have recovered and were previously vaccinated with the MMR II. No age associated factors, like a prevalence of comorbidities, showed any significant correlations with severity of illness or titer values. This eliminates the possibility that the inverse correlations observed were age related.

Researchers took 80 test subjects and divided them into 2 groups. One group was made up of 50 people who were born in the United States and showed MMR antibodies from receiving the MMR II vaccine. The second group also had MMR antibodies, but received them from other sources, such as previously being infected with measles, mumps and/or rubella.

The study found that there was a significant inverse correlation within the group who had received the MMR II vaccination between the severity of COVID-19 and the levels of mumps titers. Subjects with the highest levels of mump titers (134 to 300 AU/ml) were mostly asymptomatic and functionally immune, while subjects with the lowest titer levels (below 75 AU/ml) had the most severe cases of COVID-19.

"This is the first immunological study to evaluate the relationship between the MMR II vaccine and COVID-19. The statistically significant inverse correlation between mumps titers and COVID-19 indicates that there is a relationship involved that warrants further investigation," coauthor David J. Hurley, PhD, said. "If it has the ultimate benefit of preventing infection from COVID-19, preventing the spread of COVID-19, reducing the severity of it, or a combination of any or all of those, it is a very high reward low risk ratio intervention.”

The MMR II vaccination is considered to be very safe and has been found to have very few side effects. This study demonstrates that the vaccine could potentially play a key role in combating COVID-19 through long-term, cross-protective immunity. If the MMR II is proven to be effective, it could impact both pre- and post-clinical management of COVID-19.