A new study sheds light on the heightened risk of COVID-19 reinfection in overweight individuals, calling for more nuanced health policies and protective measures for this group.

Facing COVID-19: Being Overweight But Not Obese Does Not Reduce the Risk of Reinfection, Says a New Study

A landmark study led by the University of Queensland has uncovered that being overweight significantly impairs the body’s ability to produce antibodies in response to SARS-CoV-2 infection, although it does not affect the immune response post-vaccination.

Marcus Tong, a PhD candidate at the School of Chemistry and Molecular Biosciences and the lead researcher of the study, elaborated on these findings.

“We’ve previously shown that being overweight – not just being obese – increases the severity of SARS-CoV-2. But this work shows that being overweight creates an impaired antibody response to SARS-CoV-2 infection but not to vaccination,” he said.

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The research team’s method involved analyzing blood samples from individuals who had recovered from COVID-19.

These participants had not experienced reinfection during the study duration, which spanned approximately 3 and 13 months post-infection.

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“At 3 months post-infection, an elevated BMI was associated with reduced antibody levels. And at 13 months post-infection, an elevated BMI was associated with both reduced antibody activity and a reduced percentage of the relevant B cells, a type of cell that helps build these COVID-fighting antibodies” Tong detailed.

Interestingly, the study found that an elevated BMI did not influence the antibody response elicited by COVID-19 vaccination, measured around 6 months after the second dose.

Associate Professor Kirsty Short, contributing to the research, emphasized the study’s implications for health policy.

“If infection is associated with an increased risk of severe disease and an impaired immune response for the overweight, this group has a potentially increased risk of reinfection. It makes it more important than ever for this group to ensure they’re vaccinated.” she stated.

Dr. Short also addressed broader public health considerations. “We’d suggest that more personalised recommendations are needed for overweight people, both for ongoing COVID-19 management and future pandemics. Finally, the data provides an added impetus to improve SARS-CoV-2 vaccination in low-income countries, where there’s a high percentage of people who are overweight and are dependent on infection-induced immunity,” she added.

The team’s findings also underscore the need for improved vaccination efforts in low-income countries, where a significant proportion of the population is overweight and relies on natural immunity post-infection.

The findings of the study were published in the journal Clinical & Translational Immunology.

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