Obesity might affect how well a coronavirus vaccine works

First phase 3 coronavirus vaccine candidate begins testing in US

As the coronavirus spreads, researchers are racing to find a vaccine.

More than 150,000 people in the United States — nearly 4,000 of them in Georgia — have died from COVID-19, making the need for a vaccine urgent.

Researchers from Emory University are working with a team to create a COVID-19 vaccine. Although their vaccine has showed positive results, more work is needed to be sure it is safe.

When a vaccine is found, it might not work for everyone, Sarah Varney writes for Kaiser Health News.

In the United States, the promise of a vaccine “is hampered by a vexing epidemic that long preceded Covid-19: obesity,” she wrote.

Studies have shown that flu, hepatitis B, tetanus and rabies vaccines can be less effective in obese adults than in the general population, and there’s no reason to believe a coronavirus vaccine will be any different.

“Will we have a Covid vaccine next year tailored to the obese? No way,” Raz Shaikh, an associate professor of nutrition at the University of North Carolina-Chapel Hill, told Varney.

“Will it still work in the obese? Our prediction is no.”

According to the Centers for Disease Control and Prevention in Atlanta, 30-35% of Georgia’s adults are obese, meaning their body mass index, or BMI, is 30 or higher.

The CDC initially warned that people who were morbidly obese —having a BMI of 40 or more or were about 100 pounds overweight — were among the groups at highest risk of becoming severely ill with COVID-19.

It wasn’t long before that warning was expanded to include people with a body mass index of 30 or more.

How does obesity prevent vaccines from working correctly?

According to Varney: “A healthy immune system turns inflammation on and off as needed, calling on white blood cells and sending out proteins to fight infection. Vaccines harness that inflammatory response. But blood tests show that obese people and people with related metabolic risk factors such as high blood pressure and elevated blood sugar levels experience a state of chronic mild inflammation; the inflammation turns on and stays on.”

Although scientists are still researching its causes, it seems chronic inflammation interferes with the body’s immune response to vaccines.

“Obesity is a serious global problem, and the suboptimal vaccine-induced immune responses observed in the obese population cannot be ignored,” researchers from the Mayo Clinic’s Vaccine Research Group wrote in a 2015 study published in the journal Vaccine.

Obese individuals shouldn’t take this information to mean there is no point in getting a coronavirus vaccination, however.

Dr. Timothy Garvey, an endocrinologist and director of diabetes research at the University of Alabama at Birmingham, said it’s still safer for obese people to get vaccinated than not.

“The influenza vaccine still works in patients with obesity, but just not as well,” he said. “We still want them to get vaccinated.”