Watch CBS News

How Effective Is Moderna Vaccine Against Variants? Dr. Mallika Marshall Answers Your COVID-19 Questions

BOSTON (CBS) - Dr. Mallika Marshall is answering your coronavirus-related medical questions. If you have a question for Dr. Mallika, email her or message her on Facebook or Twitter.

Dr. Mallika is offering her best advice, but as always, consult your personal doctor before making any decisions about your personal health.

There is growing concern about two new strains of the coronavirus, one that is ravaging the United Kingdom and has now been identified in the U.S., and one in South Africa. Moderna said Monday their vaccine is still protective against both but is looking into whether a booster shot may be needed for the latter.

The Cambridge-based company says that their vaccine produces six times fewer neutralizing antibodies for the variant recently identified in South Africa, so they plan to test a booster of their two-dose vaccine to try to enhance the immune response to that particular strain.

This sounds concerning. How confident are they that their vaccine will continue to work in the meantime?

The company says they are encouraged by new data and are confident that the vaccine is effective against both the U.K. and South African variants. They say the vaccine produces enough antibodies to clear the threshold needed to neutralize the virus. But out of an abundance of caution and to be proactive, they are going to study whether a booster can be even more effective at tackling the South African variant and future variants as well. That way if the effect of the vaccine wanes in the future, they'll be ready.

We received a related question from Leslie who writes on Facebook, "I am wondering if the coronavirus will end up being like the flu - that people will have to get a vaccine shot every year against the 'new' strain."

That is certainly possible. Influenza viruses and coronaviruses do tend to mutate over time and its unclear how long immunity will last. But the beauty of the mRNA technology, used in both the Moderna and Pfizer vaccines, is that it can be used to quickly develop an effective vaccine even if mutations do occur.

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.