Obesity may weaken Covid vaccine protection

Severe obesity may weaken the effectiveness of COVID-19 vaccines in those who have never been infected with the coronavirus, according to a small Turkish study.

Among those in the study without previous SARS-CoV-2 infection who had received the Pfizer/BioNTech vaccine, patients with severe obesity had antibody levels more than three times lower than normal-weight individuals. Among recipients of Sinovac Biotech’s CoronaVac, those with severe obesity and no history of prior infection had antibody levels 27 times lower than normal weight people, according to data being presented this week at the European Congress on Obesity in Maastricht, Netherlands. By comparison, in the 70 volunteers with a previous coronavirus infection, antibody levels were similar in people with and without severe obesity.

For the study, researchers had compared immune responses to vaccines in 124 volunteers with severe obesity – defined as a body mass index of 40 or higher – and 166 normal-weight individuals (BMI less than 25). Overall, 130 participants had received two doses of the Pfizer/BioNTech mRNA vaccine and 160 had received two doses of Sinovac’s inactivated-virus vaccine.

While two doses of the Pfizer/BioNTech vaccine “may generate significantly more antibodies than CoronaVac in people with severe obesity… further research is needed to determine whether these higher antibody levels provide greater protection against COVID-19,” study leader Volkan Demirhan Yumuk from Istanbul University said in a statement.