COVID-19 Vaccines and Obesity

April 8, 2021

March 2021

In March of 2020 we published our first newsletter on the COVID-19 pandemic. At the time, we speculated that people with obesity would be adversely affected by COVID-19. One year and over 2.5 million global deaths later, we know that this is the case. According to the Centers for Disease Control and Prevention (CDC), having a BMI ≥ 30 increases a person’s risk for invasive mechanical ventilation, hospitalization, and death due to COVID-19.
Although the past year has been marked by death and despair, many are now seeing a reason to be hopeful that the end of the pandemic is near. With 3 vaccines authorized for use in the U.S. and several more in development, many are optimistic about achieving herd immunity from COVID-19 in 2021. National guidance recommends vaccinating vulnerable individuals first, although guidance has been implemented differently in each state.
In many states, individuals with a BMI ≥ 30 are considered an at-risk population that is eligible for vaccination. However, some states have introduced a bias to their vaccination rollout, prioritizing congenital diseases over those they perceive having a behavioral component. Unfortunately, this is not the first time we’ve seen weight bias contradicting science when it comes to COVID-19 vaccines. Earlier in the pandemic, there was speculation that the COVID-19 vaccine would be less effective in people with obesity. However, data from the clinical trials of all three of the U.S.-approved vaccines have shown that the vaccines are equally effective in people with obesity. Shown below are the efficacies for the Pfizer-BioNTech, Moderna, and Johnson & Johnson vaccines.


Vaccine Efficacy by BMI

Pfizer-BioNTech Moderna Johnson & Johnson
Obesity (BMI > 30) 95.4% Severe Obesity (BMI > 40) 91.2% Obesity (BMI > 30) 65.9%
No Obesity 94.8% Obesity (BMI > 30) 95.8% No Obesity 68.8%
All Participants 95% All Participants 94.5% All Participants 66.1%


Although comparing vaccine efficacy results can be confusing, it’s clear that all 3 vaccines available in the U.S. provide a comparable health benefit across BMIs. As people across the country register for vaccination, many are surprised to find that their BMIs qualify them to receive a COVID-19 vaccine as an at-risk individual. Although BMI has its flaws as a measurement of obesity, experts maintain that BMI is a valid measurement to use for vaccine prioritization because of the elevated severe illness risks observed for those at higher BMIs.
It’s important to remember that, regardless of BMI, the CDC recommends getting a COVID-19 vaccine as soon as one is available to you. Until vaccines are available to everyone, it is important that everyone continue to wear a mask, wash their hands frequently, and practice social distancing. For those who wish to know more about COVID-19 and obesity, several resources are available on the STOP Obesity Alliance website.