In a new alarming discovery, scientists have said that obesity can also result in the loss of immune response to viruses relatively quickly and they may require frequent inoculation of booster doses.
According to the research findings published in the journal Nature Medicine, 55% of people who are severely obese had no longer antibodies to fight COVID after six months of their second dose.
On the contrary, 12% of healthy people lost their protective antibodies by the same point.
Experts were unsure about what is causing it, but are examining whether hormones elevated in obese people are talking with immune cells to prevent long-term antibody generation.
There were concerns about short needles of vaccines being unable to penetrate more into obese people. However, it was ruled out after discovering that antibody levels are high initially after the jab.
"I don’t think too short needles were a factor contributing to our findings — we found that vaccine-triggered antibody levels, shortly after vaccination, were actually higher in people with obesity," said Dr James Thaventhiran, from Cambridge’s Medical Research Council (MRC) Toxicology Unit.
Dr Thaventhiran also added: "Our data shows that waning of protection occurs more rapidly with increasing body weight."
"Why this happens is unknown. We are actively investigating whether the cross-talk between the immune cells and the hormones and other signalling molecules which are elevated with obesity leads to an impairment that prevents normal antibody generation."
During the COVID-19, Obese people were more likely to be hospitalised, needed ventilators, and died due to the virus.
The new research put forth a suggestion that vaccine protection warnings may have played a role.
In the study, Edinburgh University scientists monitored the health of 3.5 million people in Scotland who got Pfizer or AstraZeneca jabs and found that obese people — a body mass index (BMI) greater than 40kg/m2 — had a 76% higher risk of the severity of the virus as compared to those with a normal BMI.
They also revealed that severely obese people had been hospitalised and died sooner due to breakthrough infections after their second dose of the vaccine.
"More frequent booster doses are likely to be needed to maintain protection against COVID-19 in people with obesity. Because of the high prevalence of obesity across the globe, this poses a major challenge for health services," said Professor Sadaf Farooqi from the Wellcome-MRC Institute of Metabolic Science.