How Obesity and Other Conditions Could Hinder the Effectiveness of a COVID-19 Vaccine

ISLAMABAD, August 14 (Online): Experts say obesity, as well as other factors such as diabetes and older age, can inhibit a vaccine’s ability to produce effective antibodies against a virus.

Several promising COVID-19 vaccines have moved into the final stages of clinical trials in order to be approved for use by the general public.

But even when we have a safe vaccine in hand, some experts have raised concerns that the United States’ high obesity rate — as well as other factors — might influence how effective those vaccines are in producing immunity to the novel coronavirus.

“A vaccine is typically utilized to raise neutralizing antibody levels in the body so that an individual can be protected,” said Chris Xu, PhD, chief executive officer of biotech company ThermoGenesis, which has developed rapid COVID-19 antibody tests and studied the disease in detail.

“Researchers believe that due to increased production of leptin (which correlates with body fat mass) and fat, the obese population has a more difficult time gaining vaccine-induced antibody protection,” Xu told Healthline.

More than 40 percentTrusted Source of adults, as well as 18 percentTrusted Source of children in the United States, have obesity, according to the Centers for Disease Control and Prevention (CDC).

That could spell trouble if the eventual COVID-19 vaccines induce a weaker immune response in people with obesity.

Scientists first found a link between obesity and lower vaccine effectiveness in the 1970s when studying the hepatitis B vaccine.

Since then, researchers have identified lower vaccine immune response with the influenza A/H1N1 vaccineTrusted Source as well as with rabies and tetanus vaccines among people with obesity.

The reason has less to do with being overweight, per se, as much as the excess inflammation that comes with it, said Dr. John Morton, the division chief of bariatric and minimally invasive surgery at Yale Medicine in Connecticut.

“What we know is that the vaccines in general do not work as well in patients who have obesity,” he told Healthline. “Inflammation can attack the vaccine and make it less effective.”

In fact, people with obesity can often produce healthy levels of antibodies following a vaccine but still display less protection from a virus because of other inflammation-induced deficiencies in the body’s immune response.

That means other inflammatory conditions or conditions that inhibit the immune system — including older age — can also reduce a vaccine’s effectiveness.

“The ability of an individual to be able to respond to a vaccine is dependent on their immune system,” Xu explained. “Data suggests that people that are obese inhibit T-cell activation, which plays an important role in providing protective antibodies.”

Diabetes, which often goes hand-in-hand with obesity, should also get a close look, he added.

“Diabetes has shown to be a risk factor that associates with the weakening of the immune system, therefore, potentially could affect the effectiveness of a vaccine,” Xu said. “In addition, the vaccine’s safety profile in diabetic patients may need to be carefully examined.”

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