Obesity may impair vaccine protection;  Unvaccinated Omicron patients face risks from variants

Obesity may impair vaccine protection; Unvaccinated Omicron patients face risks from variants

The syringes used to give doses of the Pfizer-BioNTech vaccine against coronavirus disease (COVID-19) are photographed in a sharps container at a booster clinic for children ages 12 to 17 in Lansdale, Pennsylvania, US, January 9, 2022. Photo: Hannah Beer – Reuters

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May 6 (Reuters) – Here is a summary of some recent studies on COVID-19. They include research that requires further study to confirm results and that has not yet been approved by peer review.

Obesity may impair vaccine protection in people who have never been infected

A small Turkish study shows that obesity may impair the effectiveness of COVID-19 vaccines in those who have never had the coronavirus.

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Among those who participated in the study without prior SARS-CoV-2 infection and who received the Pfizer (PFE.N)/BioNTech vaccine, obese patients had antibody levels three times lower than individuals of normal weight. Among the CoronaVac recipients from Sinovac Biotech (SVA.O), people who were obese with no history of previous infection had antibody levels 27 times lower than people of normal weight, according to data presented this week at the European Congress on Obesity. in Maastricht, The Netherlands. By comparison, in the 70 volunteers who had previously contracted coronavirus, antibody levels were similar in obese and non-obese people.

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

While two doses of the Pfizer/BioNTech vaccine “may generate significantly more antibodies than CoronaVac in obese people…More research is needed to determine whether these higher antibody levels provide greater protection against COVID-19.” Study leader Volkan Demirhan Yumuk of Istanbul University said in a statement

Unvaccinated Omicron patients at risk for variants

South African researchers have found that infection with the Omicron variant of the coronavirus can significantly improve the immune system’s ability to protect against other variants, but only in vaccinated people.

In unvaccinated people, omicron infection provides only “limited” protection from reinfection, they report Friday in the journal Nature. In 39 patients who developed an Omicron infection — including 15 who had been immunized with vaccines from Pfizer/BioNTech or Johnson & Johnson (JNJ.N) — the researchers measured the ability of immune cells to neutralize not only Omicron but also its precursor variants. On average 23 days after Omicron symptom onset, unvaccinated patients had 2.2-fold lower neutralization of the first version of the Omicron variant than vaccinated subjects, 4.8-fold lower neutralization of the second Omicron sub-series, 12-fold lower neutralization, 9.6 Lower beta variant neutralization fold, and 17.9 fold lower neutralization for the original SARS-CoV-2 strain. The researchers said the gap in immunity between unvaccinated and vaccinated individuals was “alarming”.

“Especially with diminished immunity, it is likely that non-immunized individuals following omicron infection may have poor cross-protection against current and possibly emerging variants of SARS-CoV-2,” they said. “The implication may be that omicron infection alone is not sufficient for protection and vaccination should be given even in areas where omicron infection is common to protect against other variants.”

Various vaccines protect well against severe COVID-19

Whereas mRNA vaccines from Pfizer/BioNTech and Moderna (mRNA.O) generate higher levels of antibodies to protect against SARS-CoV-2 infection, the virus-based AstraZeneca (AZN.L) vaccine provides equivalent protection against hospitalization and death from COVID-19 according to a review of dozens of studies.

A panel of Southeast Asian experts reviewed 79 previous studies of an AstraZeneca-funded study. In a report published on Research Square ahead of peer review, panel members said both types of vaccines have shown more than 90% effectiveness against hospitalization and death. “The high level of antibodies formed after a COVID-19 vaccine is often interpreted as a vaccine’s efficacy. We now understand that although levels of initial antibody response can vary for different vaccines, their ability to prevent hospitalization or death due to COVID-19 is the equivalent,” panel member Dr. Erlena Burhan, a pulmonologist at the University of Indonesia, said in a statement.

A spokesperson for panel members said the findings suggested decision makers should use whichever type of vaccine is accessible and ideal for their local situation, and that people with a vaccine choice should know that the vaccine they can get the fastest is best.

A separate study published in Nature Communications found that while Moderna’s mRNA shots offered slightly greater protection against coronavirus infection than the Pfizer/BioNTech vaccine, “there are no differences in vaccine efficacy to protect against hospitalization, ICU admission, or death/reproduction transfer.” .

Click for a Reuters graphic of vaccines in development.

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(Nancy Lapid reports). Editing by Bill Bercrot

Our Standards: Thomson Reuters Trust Principles.

2022-05-06 17:58:00

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