According to a Turkish study, severe obesity may weaken the effectiveness of COVID-19 vaccines in those who have never been infected with the coronavirus.
Among those in the study without previous SARS-CoV-2 infection who had received the Pfizer /BioNTech vaccine, patients with severe obesity had antibody levels more than three times lower than normal-weight individuals. Among recipients of Sinovac Biotech’s CoronaVac, those with 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. By comparison, in the 70 volunteers with a previous coronavirus infection, antibody levels were similar in people with and without severe obesity.
For the study, researchers had compared immune responses to vaccines in 124 volunteers with severe obesity – defined as a body mass index 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.
While two doses of the Pfizer/BioNTech vaccine “may generate significantly more antibodies than CoronaVac in people with severe obesity… further research is needed to determine whether these higher antibody levels provide greater protection against COVID-19,” study leader Volkan Demirhan Yumuk from Istanbul University said in a statement
Infection with the Omicron variant of the coronavirus can significantly improve the immune system’s ability to protect against other variants, but only in people who have been vaccinated, South African researchers have found.
In unvaccinated people, an Omicron infection provides only “limited” protection against reinfection, they reported on Friday in Nature. In 39 patients who had Omicron infections – including 15 who had been immunized with vaccines from Pfizer/BioNTech or Johnson & Johnson – the researchers measured the ability of immune cells to neutralize not only Omicron but also earlier variants. At an average of 23 days after Omicron symptoms started, unvaccinated patients had 2.2-fold lower neutralization of the first version of the Omicron variant compared to vaccinated people, 4.8-fold lower neutralization of the second Omicron sublineage, 12-fold lower Delta neutralization, 9.6-fold lower Beta variant neutralization, and 17.9-fold lower neutralization of the original SARS-CoV-2 strain. The gap in immunity between unvaccinated and vaccinated individuals “is concerning,” the researchers said.
“Especially as immunity wanes, unvaccinated individuals post-Omicron infection are likely to have poor cross-protection against existing and possibly emerging SARS-CoV-2 variants,” they said. “The implication may be that Omicron infection alone is not sufficient for protection and vaccination should be administered even in areas with high prevalence of Omicron infection to protect against other variants.”
While the mRNA vaccines from Pfizer/BioNTech and Moderna generate higher antibody levels to protect against SARS-CoV-2 infection, AstraZeneca’s viral-vector-based vaccine provides equivalent protection against hospitalization and death from COVID-19, according a review of dozens of studies.
A panel of experts in Southeast Asia reviewed 79 previous studies for a study funded by AstraZeneca. Both types of vaccines showed over 90% efficacy against hospitalization and death, the panelists said in a report posted on Research Square ahead of peer review. “The high level of antibodies formed after the COVID-19 vaccination is often interpreted as the effectiveness of a vaccine. We now understand that while initial antibody response levels can vary across vaccines, their ability to prevent being hospitalized or dying from COVID-19 is equivalent,” panel member Dr. Erlina Burhan, a lung disease specialist at the University of Indonesia, in a statement.
Luckily here in the Philippines, the national government has prepared an aggressive COVID-19 vaccination program that enabled its citizen to achieve herd immunity. Vaccines of different brands were readily availanle that is why as early as last quarter of last year, we can say that we are now experiencing the post pandemic where almost all businesses are back to normal.
With additional reports: Reuters