COVID-19 Q&A: Does body size and weight affect how well the vaccine works?

ANCHORAGE, Alaska (KTUU) - Alaska News Source is answering viewer questions about the COVID-19 vaccine.

Question:

“Are the COVID vaccines that are currently available as effective on someone whose body mass is larger than the size of another individual who has a regular BMI? As with most anything, it usually takes a larger dose for larger people to be as effective as a regular dose for an average person.” - Beth

Answer:

Alaska’s Chief Medical Officer Dr. Anne Zink said studies show the vaccines should work well regardless of body size.

“The big studies done for Pfizer, Moderna were done in big trials, and so they had over 30 and over 40,000 people in each trial of different ages, of different ethnic groups, different sizes, different people who had been exposed to COVID and who hadn’t. And what they found is that all of those other factors did not make a difference in someone’s immune response system. People have of all sorts of ages, sizes, colors, all seem to have a fairly similar robust immune response to it,” Zink said.

More information on the Moderna vaccine, including clinical trials, is available here. More information on the Pfizer vaccine, including clinical trials, is available here.

Editor’s Note: Viewer questions are lightly edited for clarity.