Coronavirus Vaccine May Not Work Well for Obese People, Researchers Warn

The inefficacy can make the obese people, who are already at risk of contracting coronavirus, vulnerable amid the pandemic

As several countries race to make a vaccine on coronavirus, American researchers on Friday warned that the potential medication is less likely to be efficient on obese people. The inefficacy can make the obese people, who are already at risk of contracting Covid-19, more vulnerable amid the pandemic.

Researchers explain that obesity pushed the body's immune response that led to excessive inflammation. This, in turn, made the body less ineffective in fighting the virus.

"It is not a question of not working, it is more of a question of efficacy,' Dr Chad Petit, an assistant professor at the University of Alabama at Birmingham, told "In other words, the vaccine [could work] but it [may not be] as effective."

Earlier this year, the Centers for Disease Control and Prevention warned that people who fell into the morbidly obese category – body mass index of 40 or more – were at highest risk of falling severely ill with the coronavirus. Later, the CDC added that obese people with a body mass index of 30 or more were also at the same risk as the morbidly obese people in falling sick with Covid-19.

coronavirus infection

According to Dr William Schaffner, the size of the vaccine needle matters for obese people since the standard one-inch needle could prove less effective on them.

"Physicians have to very mindful what needle-length to use so that, if you're giving an intramuscular injection, it can actually reach the muscle," Dr Schaffner, who is a professor at the Vanderbilt University Medical Center in Nashville, told

It was in 1985 when scientists first found that obesity could weaken the vaccine's efficacy after studying that the immunity for hepatitis B diminished quickly among obese hospital workers in a matter of 11 months after taking the vaccination. Similar observations were found among obese people who had their vaccinations hepatitis A, influenza, rabies, and tetanus.

However, researchers said it was important to get flu shots no matter what. "We want to encourage everyone to get the flu shot. This winter, both Covid and flu will be active. The flu vaccine isn't perfect, but we know it can prevent infection and. even if not, it will be milder," Dr Schaffner reportedly said.

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Petit explained that obese adults who got their influenza vaccine in previous studies were well protected. "In other words, less protection is definitely better than no protection," he reportedly said.

Since the coronavirus was declared a pandemic by the World Health Organization earlier this year, scientists across countries have been working to make a vaccine. On Friday, it was reported that Russia's Health Ministry's would register its potential coronavirus vaccine.

This would be the world's first Covid-19 vaccine to have been registered and it would be used for a nationwide immunization program that is slated to be launched in October.