A recent study published in the journal Nature Medicine examines the effectiveness of COVID-19 vaccines in obese individuals compared to those with a normal body mass index (BMI). The research reveals that obesity can affect the immune response to vaccines and potentially increase the risk of severe COVID-19 outcomes. The study analysed data from vaccinated individuals in Scotland, including those with severe obesity and a normal BMI. It found that severely obese individuals had lower levels of neutralising antibodies six months after vaccination compared to those with a normal BMI. However, peak antibody levels were higher in the severely obese group. The findings suggest that while vaccines can target the virus in obese individuals, the reduced neutralising capacity of antibodies may impact the effectiveness of the vaccine. The study highlights the importance of targeted strategies and further research to optimise COVID-19 vaccine responses in the obese population.