COVID-19 Vaccines Far Less Effective in People With Severe Obesity: Study

A health worker fills a syringe with Ebola vaccine before injecting it to a patient, in Goma, Democratic Republic of Congo, on Aug. 5, 2019. Baz Ratner/Reuters

Severe obesity may weaken the effectiveness of COVID-19 vaccines among individuals who have never been infected with the virus, according to a small study published this month.

A study conducted by Professor Volkan Demirhan Yumuk from Istanbul University in Turkey found that adults aged 18 or older with severe obesity have a much weaker immune response to the vaccine as compared with individuals with normal weight, according to a news release from the European Association for the Study of Obesity.

Among those in the study without previous a COVID-19 infection who had received the Pfizer/BioNTech mRNA vaccine, patients with severe obesity had antibody levels more than three times lower than normal-weight individuals. Those who received the Chinese-made CoronaVac and who had severe obesity and no history of prior infection had antibody levels 27 times lower than normal-weight people, according to data being presented this week at the European Congress on Obesity in Maastricht, Netherlands.

For the study, researchers had compared immune responses to vaccines in 124 volunteers with severe obesity—defined as a body mass index (BMI) of 40 or higher—and 166 normal-weight individuals (BMI less than 25). Overall, 130 participants had received two doses of the Pfizer/BioNTech mRNA vaccine and 160 had received two doses of Sinovac’s inactivated-virus vaccine.

“These results provide new information on the antibody response to SARS-CoV-2 vaccines in people with severe obesity and reinforce the importance of prioritizing and increasing vaccine uptake in this vulnerable group,” Yumuk said in the news release, referring to severely obese individuals. SARS-CoV-2, a type of coronavirus that causes COVID-19, is another name for the CCP (Chinese Communist Party) virus.

“Our study confirms that immune memory induced by prior infection alters the way in which people respond to vaccination and indicates that two doses of Pfizer/BioNTech vaccine may generate significantly more antibodies than CoronaVac in people with severe obesity, regardless of infection history. However, further research is needed to determine whether these higher antibody levels provide greater protection against COVID-19,” he added.

In March, another study commissioned by the World Obesity Fund suggested that individuals who are obese should be prioritized for COVID-19 vaccines. Researchers with the organization said that 2.2 million of the 2.5 million COVID-19 deaths reported in February occurred in countries where at least half the population can be considered overweight or obese.

They called on countries to note that obesity can lead to an elevated “risk factor for other conditions, including significantly worsening the outcomes of COVID-19 infection,” noting that dealing with the obesity crisis “would have resulted in far less stress on health services and reduced the need to protect those services from being overwhelmed.”

Reuters contributed to this report.