Severe obesity impairs antibody response to COVID-19 vaccine, study shows

Compared with normal-weight adults, severely obese adults ( 18 years or older) had a significantly weaker immune response to the COVID-19 vaccine

The study also found that people with severe obesity (BMI over 40kg/m2) produced significantly more antibodies after receiving the Pfizer/BioNTech BNT162b2 mRNA vaccine than those receiving the coronavirus vaccine, suggesting that the Pfizer/BioNTech vaccine may be a better option for this vulnerable population select

Obesity is a disease that complicates the course of COVID-19, and SARS-CoV-2 vaccine antibody responses in obese adults may be affected

To learn more, the researchers surveyed 124 severely obese adults (average age 42-63) who visited Istanbul University's Cerrahpasa Obesity Center, Cerrahpaña Medical Faculty Hospitals, at Pfizer, between August and November 2021.

The researchers measured antibody levels in blood samples from patients and normal-weight controls who received two doses of the Pfizer/Biotech or CoronaVac vaccine and a second dose four weeks earlier

Overall, 130 participants received two doses of Pfizer/Biotech and 160 participants received two doses of CoronaVac, 70 of whom were previously infected with SARS-CoV-2 (see table in Editor's Notes)

Among those who had not been infected with SARS-CoV-2 and had received the Pfizer/Biotech vaccine, severely obese patients had antibody levels more than three times lower than normal-weight controls (average 5823 vs 19371 AU/ml; note to editors) in Table 1)

Likewise, among participants not previously infected with SARS-CoV-2 and vaccinated against the coronavirus, severely obese patients had 27-fold lower antibody levels than normal-weight controls (mean 178 vs 4894 AU/ml; in a note to the editor).

However, among patients previously infected with SARS-CoV-2, antibody levels in severely obese patients and those vaccinated with Pfizer/Biotech or CoronaVac were not significantly different from normal-weight controls (mean 39043 vs 14,115 AU/ml and 3221 AU/ml vs.

Interestingly, the analysis found that among severely obese patients, with or without previous SARS-CoV-2 infection, those vaccinated with Pfizer/Biotech had significantly higher levels of antibodies than those vaccinated with CoronaVac

"These results provide new information on the antibody response to the SARS-CoV-2 vaccine in severely obese people and underscore the importance of prioritizing and increasing vaccine uptake in this vulnerable population," Professor Yumuk said