Scientists from the University of Cambridge found that obesity accelerates the weakening of immunity after vaccination against COVID-19. The results of the research have been published magazine nature medicine.
“We know that obese people have an impaired immune response to other vaccines, including flu, rabies, and hepatitis vaccines. But the effect on COVID vaccines has been little studied,” he said.
Vaccines help the body produce antibodies that recognize spike protein (a protein found on the surface of SARS-CoV-2 that allows it to attach to and infect cells). Vaccines also stimulate immune cells called T cells to protect against severe COVID-19.
Various studies have shown that antibody levels may be lower in obese people after vaccination than in the general population.
Using a data platform called EAVE II, the team analyzed the health data of 5.4 million people across Scotland. Specifically, they looked at hospitalizations and deaths due to COVID-19 among 3.5 million adults who received two doses of the vaccine (Pfizer or AstraZeneca).
They found that severely obese people with a body mass index over 40 had a 76% higher risk of hospitalization and death from COVID after vaccination than people with a BMI in the normal range. The risk was also moderately increased in people with a BMI of 30 to 40 and those with low weight (below a BMI of 18.5).
“Our team conducted experiments to characterize the immune response to a third dose or booster in extremely obese people. We studied 28 extremely obese people and measured antibody levels and function, as well as the number of immune cells in their blood after vaccination. We compared the results with those of 41 normal-weight subjects,” he said. stated authors.
Although antibody levels were similar in all samples, the ability of antibodies to effectively fight the virus was reduced in people with severe obesity. This could mean that COVID vaccines cause lower quality antibody synthesis in obese people.