COVID-19 Vaccination and Obesity: Optimism and Challenges.

Researchers have speculated that vaccines to prevent coronavirus disease 2019 (COVID-19) may be less effective for individuals with obesity, a major risk factor for mortality and morbidity from COVID-19. Initial results from the Pfizer-BioNTech and Moderna COVID-19 vaccine trials, though limited by inadequate power to compare subgroups and incomplete stratification of high-risk groups, appear to have similar efficacy among individuals with and without obesity. Careful follow-up in placebo-controlled studies is required to generate data on long-term vaccine immunogenicity, particularly in high-risk groups. Subsequent analyses should stratify safety and efficacy results by each class of obesity. Speculation about variable effectiveness of COVID-19 vaccines in obesity likely increases vaccine hesitancy among individuals with obesity, who face not only a higher risk of severe outcomes from COVID-19 but also weight stigma, which reduces health care engagement at baseline. Clinical and public health messaging must be data driven, transparent, and sensitive to these biological and sociological vulnerabilities.