Obese people need more COVID-19 boosters: study

By Mark Waghorn via SWNS

Obese people need frequent 'booster' COVID-19 jabs - just like the elderly, according to new research.

Vaccines used to protect people from the virus are less effective in overweight patients as immunity wears off faster, scientists said.

Infected patients are also often worse hit by the virus if they are morbidly overweight, researchers added.

Millions of participants were analyzed for the study that found morbidly obese people, with a BMI (body mass index) higher than 40, were 76 percent more likely to get severe COVID-19 symptoms than those of normal girth.

A smaller increase in risk was also discovered in those with a BMI of at least 30, which affects a quarter of Britons, and those who were underweight.

Infections after the second dose also led to hospitalization and death sooner, from 10 and 15 weeks, among each obesity group, respectively.

This was up to twice as long than for people of normal weight, who ended up in hospital on average 20 weeks after infection, the study found.

Professor Sir Aziz Sheikh, of the University of Edinburgh and a lead author of the study, said: "Our findings demonstrate that protection gained through COVID-19 vaccination drops off faster for people with severe obesity than those with a normal body mass index.

"Using large-scale data assets such as the EAVE II Platform in Scotland have enabled us to generate important and timely insights that enable improvements to the delivery of COVID-19 vaccine schedules in a post-pandemic UK."

His team tracked 3.5 million individuals north of the border - analyzing hospitalization and mortality rates in those who received two Pfizer or AstraZeneca jabs.

Clinical trials have shown the vaccines can dramatically reduce symptoms, hospitalization and deaths - including for people with obesity.

Co-lead author Prof Sadaf Farooqi, from the Wellcome-MRC Institute of Metabolic Science, Cambridge, said: "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."

Previous studies suggested lower antibody levels in vaccinated people who have obesity - making them more vulnerable. But the reasons remained unclear.

The study in Nature Medicine found their power declines quicker. It has important implications for prioritization policies around the world.

During the pandemic, obese people were more likely to be hospitalized, require ventilators - and die.

The Cambridge group analyzed severely obese patients attending the city's Addenbrooke's Hospital, comparing the number and function of immune cells in their blood to those of normal weight.

They found six months after a second vaccine dose, the former similar levels of antibodies to virus. But they were not as good at fighting it.

More than half (55 percent) had undetectable 'neutralizing capacity’ - compared to 12 percent of those with normal BMI.

Dr. Agatha van der Klaauw, the first author of the study, said: "This study further emphasizes obesity alters the vaccine response and also impacts on the risk of infection.

"We urgently need to understand how to restore immune function and minimize these health risks."

It is believed the antibodies were not able to bind to the SARS-CoV-2 virus, which causes COVID-19, with the same strength.

But when given a third 'booster' dose, their ability was restored in normal weight and severely obese groups. But immunity again declined more rapidly in the latter, putting them at greater risk of infection with time.

Dr. James Thaventhiran, of the MRC Toxicology Unit and a co-lead author, said: "It is promising to see that booster vaccines restore the effectiveness of antibodies for people with severe obesity, but it is concerning that their levels decrease more quickly, after just 15 weeks.

"This shows that the vaccines work as well in people with obesity, but the protection doesn't last as long."

Currently the NHS encourages seasonal boosters if you are aged 75 or over, live in a care home, or have a weakened immune system.

Around 6.4 million people are eligible for the jab because of a medical condition - a number that would soar if obese individuals were invited.

The findings of the research were published in Nature Medicine.