COVID-19 Summary: Obesity weakens vaccine protection and risks mutations

In this week’s summary, the latest scientific research, including coronavirus treatments and vaccines, suggests that obesity may weaken vaccine protection in people who have never been infected with COVID-19, and unvaccinated Omicron patients It may be at risk for variants and it has been suggested that various vaccines provide adequate protection against severe infections.

Obesity weakens people who have never been infected

Severe obesity may reduce the effectiveness of the COVID-19 vaccine in people who have never been infected with the coronavirus, according to a small Turkish study.

Among patients in previous SARS-CoV-2 infection-free studies who received the Pfizer / BioNTech vaccine, antibody levels in severely obese patients were more than one-third that of individuals of normal body weight.

According to data released this week at the European Obesity Conference in Maastricht, the Netherlands, the antibody levels of Sinovac Biotech’s CoronaVac recipients who are severely obese and have no previous history of infection are those of normal weight. It was 1/27 of.

By comparison, 70 volunteers previously infected with the coronavirus had similar antibody levels in those with and without severe obesity.

In this study, researchers compared the immune response to vaccines in 124 severely obese volunteers with a body mass index of 40 or higher and 166 normal-weight individuals (BMI <25). .. Overall, 130 participants received two Pfizer / BioNTech mRNA vaccines and 160 received two Sinovac inactivated virus vaccines.

Two doses of the Pfizer / BioNTech vaccine can produce “much more antibodies than CoronaVac in severely obese people … these high antibody levels enhance protection against COVID-19. Further research is needed to determine whether or not to do so, “research leader Volkan Demirhan Yumuk said in a statement from the University of Istanbul.

Unvaccinated Omicron patients

Infection with the Omicron variant of the coronavirus can significantly improve the immune system’s ability to protect against other mutants, but only those who have been vaccinated have been found by South African researchers.

In unvaccinated people, Omicron infections provide only “limited” protection against reinfection, they reported in Nature on Friday. In 39 patients with Omicron infection, including 15 immunized with the Pfizer / BioNTech or Johnson & Johnson vaccine, researchers have shown that immune cells have the ability to neutralize not only Omicron but also previous variants. I measured it.

On average 23 days after the onset of Omicron symptoms, unvaccinated patients had 2.2-fold lower neutralization of the first version of the Omicron variant compared to vaccinated people and of the second Omicron subline. Neutralization is 4.8 times lower and delta neutralization is 12 times lower. 9.6-fold lower beta mutant neutralization and 17.9-fold lower neutralization of the original SARS-CoV-2 strain.

The immune gap between unvaccinated and vaccinated individuals is “concerned,” the researchers said.

“Especially as immunity weakens, unvaccinated individuals after Omicron infection are likely to have inadequate cross-protection against existing and possibly newly emerging SARS-CoV-2 mutants.” They said.

“Omicron infection alone is not sufficient to protect against it, which may mean that vaccination is needed even in areas with a high prevalence of Omicron infection to protect it from other variants. “

Various vaccines protect well

Pfizer / BioNTech and Modena messenger RNA (mRNA) vaccines produce high antibody levels to protect against SARS-CoV-2 infection, whereas AstraZeneca viral vector-based vaccines are hospitalized with COVID-19. And provide equal protection against death. Of dozens of studies.

A panel of Southeast Asian experts reviewed 79 previous studies for AstraZeneca-sponsored studies. Panelists said in a report posted to Research Square prior to peer reviews that both types of vaccines were more than 90% effective against hospitalization and death.

“High levels of antibody formed after COVID-19 vaccination are often interpreted as vaccine efficacy. Initial antibody response levels may vary from vaccine to vaccine, but may include hospitalization with COVID-19. The ability to prevent death is comparable. ” Dr. Erlina Burhan, a panel member who is a specialist in lung diseases at the University of Indonesia, said in a statement.

A panelist spokesperson said the findings show that decision makers need to use the most suitable vaccine type with access to the local situation, and those who can choose the vaccine are best available the earliest. Said suggesting that you need to know.

According to another study published in Nature Communications, Moderna’s mRNA shots have slightly higher protection against coronavirus infection than the Pfizer / BioNTech vaccine, but “protection against hospitalization, ICU admission, or death / hospital relocation.” There is no difference in the effectiveness of the vaccine. “

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