Obesity is associated with an increased risk of severe Coronavirus Disease 2019 (COVID-19) infection and mortality. COVID-19 vaccines reduce the risk of serious COVID-19 outcomes; however, their effectiveness in people with obesity is incompletely understood. We studied the relationship among body mass index (BMI), hospitalization and mortality due to COVID-19 among 3.6 million people in Scotland using the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) surveillance platform. We found that vaccinated individuals with severe obesity (BMI > 40 kg/m2) were 76% more likely to experience hospitalization or death from COVID-19 (adjusted rate ratio of 1.76 (95% confidence interval (CI), 1.60-1.94). We also conducted a prospective longitudinal study of a cohort of 28 individuals with severe obesity compared to 41 control individuals with normal BMI (BMI 18.5-24.9 kg/m2). We found that 55% of individuals with severe obesity had unquantifiable titers of neutralizing antibody against authentic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus compared to 12% of individuals with normal BMI (P = 0.0003) 6 months after their second vaccine dose. Furthermore, we observed that, for individuals with severe obesity, at any given anti-spike and anti-receptor-binding domain (RBD) antibody level, neutralizing capacity was lower than that of individuals with a normal BMI. Neutralizing capacity was restored by a third dose of vaccine but again declined more rapidly in people with severe obesity. We demonstrate that waning of COVID-19 vaccine-induced humoral immunity is accelerated in individuals with severe obesity. As obesity is associated with increased hospitalization and mortality from breakthrough infections, our findings have implications for vaccine prioritization policies.


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Cite as

van der Klaauw, A., Horner, E., Pereyra-Gerber, P., Agrawal, U., Foster, W., Spencer, S., Vargese, B., Smith, M., Henning, E., Ramsay, I., Smith, J., Guillaume, S., Sharpe, H., Hay, I., Thompson, S., Innocentin, S., Booth, L., Robertson, C., McCowan, C., Kerr, S., Mulroney, T., O'Reilly, M., Gurugama, T., Gurugama, L., Rust, M., Ferreira, A., Ebrahimi, S., Ceron-Gutierrez, L., Scotucci, J., Kronsteiner, B., Dunachie, S., Klenerman, P., PITCH Consortium, Park, A., Rubino, F., Lamikanra, A., Stark, H., Kingston, N., Estcourt, L., Harvala, H., Roberts, D., Doffinger, R., Linterman, M., Matheson, N., Sheikh, A., Farooqi, S. & Thaventhiran, J. 2023, 'Accelerated waning of the humoral response to COVID-19 vaccines in obesity', Nature Medicine, 29, pp. 1146-1154. https://doi.org/10.1038/s41591-023-02343-2

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Last updated: 30 May 2023
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