Pfizer vaccine may be less effective in people with obesity, says study

LONDON: The Pfizer/BioNTech vaccine may be less effective in people with obesity, data suggests, foreign media reported.

Italian researchers have discovered that healthcare workers with obesity produced only about half the amount of antibodies in response to a second dose of the jab compared with healthy people. Although it is too soon to know what this means for the efficacy of the vaccine, it might imply that people with obesity need an additional booster dose to ensure they are adequately protected against coronavirus.

Previous research has suggested that obesity – which is defined as having a body mass index (BMI) over 30 – increases the risk of dying of Covid-19 by nearly 50%, as well as increasing the risk of ending up in hospital by 113%.

Some of this may be because people with obesity often have other underlying medical conditions, such as heart disease or type 2 diabetes, that increase their risk from the coronavirus, but excess body fat can also cause metabolic changes, such as insulin resistance and inflammation, which make it harder for the body to fight off infections.

This constant state of low-grade inflammation can also weaken certain immune responses, including those launched by the B and T cells that trigger a protective response following vaccination. Separate research has shown that the flu vaccine is only half as effective in people with obesity compared to those who are a healthy weight.