Obesity was flagged as a risk factor for severe COVID-19 early in the global pandemic. The UK’s vaccine programme in 2021 gave priority to people with a BMI over 40, categorising them as a high-risk group. However, prior to this study, little was known about the effectiveness of the COVID-19 vaccines for overweight people and those with obesity.
The new study, led by researchers at the University of Oxford, also found that vaccinated people with underweight or overweight are at greater risk of hospitalisation and death compared with vaccinated people of healthy weight. This replicates the findings seen in a previous analysis before the vaccination programme began. Moreover, the findings suggest that underweight people were less likely to be vaccinated, although the reasons for this are not well understood.