This week’s collection of some of the latest scientific studies on the coronavirus and efforts to find cures and vaccines for COVID-19 revisits concerns about vaccine overdose and efficacy and builds hope one dose may be sufficient in some cases.
One dose may be sufficient for COVID-19 survivors
COVID-19 survivors may only need one picture of the new vaccines from Moderna Inc. and Pfizer / BioNTech, instead of the usual two doses, because their immune systems have begun to experience the recognition of the virus, according to two separate reports. posted on medRxiv ahead of peer review.
In one study of 59 health care workers who received COVID-19 and received one of the vaccines, antibody levels after the first picture were higher than levels typically seen after two doses in people without a history of COVID-19. In a separate study, researchers found that 41 survivors of COVID-19 developed “high antibody titers within days of vaccination,” and these levels were 10 to 20 times higher than in the unprotected, unvaccinated volunteers after only one dose of vaccine.
“The antibody response to the first dose of vaccine in individuals with a previous immune system is equal to or even higher than the levels” found in unprotected individuals after the second vaccine dose, the authors of that paper. “Changing the policy to give these people just one dose of the vaccine would not adversely affect their antibody titers, freeing them from unnecessary pain and freeing many emergency doses of vaccines,” he said. them.
The Oxford / AstraZeneca vaccine may work best with doses months apart
Among the recipients of the COVID-19 vaccine from Oxford University and AstraZeneca, extending the interval between the first and second doses resulted in better results, researchers said in a paper posted last week ahead of a peer review by the Lancet on its introductory site.
For volunteers ages 18 to 55, vaccine efficacy was 82.4% with 12 or more weeks between doses, compared with 54.9% when the increase was given within six weeks after the first dose. The maximum interval between doses given to older volunteers was eight weeks, so there were no data for the efficacy of a 12-week dosing gap in that group.
The European medicines regulator has said there is not enough data to determine how well the vaccine works in people over 55. According to their findings, the authors say, “A second dose is an effective strategy that is given after three months … and this is probably the best way to introduce a pandemic vaccine when not there are not many products in the short term. “
Delays in the second dose of the COVID-19 vaccine have been a controversial issue in the medical community.
J&J vaccine 66% effective in global testing
Johnson & Johnson’s single-dose vaccine was 66% effective in preventing moderate and severe COVID-19 in a late-stage global trial with nearly 44,000 volunteers including regions with anxious changes of the virus, the company said.
Protection levels 28 days after vaccination changed from 72% in the United States to 66% in Latin America and just 57% in South Africa, where a strong new variant has become commonplace. Two-dose vaccines from Pfizer / BioNTech and Moderna were approximately 95% effective in significant trials, but these were carried out before the emergence of the highly adaptable new variants.
“Right now, any protection and additional vaccinations are good,” said Walid Gellad, an associate professor of health policy at the University of Pittsburgh who was not involved in the trial. “The key is not only overall effectiveness but especially effectiveness against serious disease, hospitalization and death.”
In a press release, J&J said his vaccine was 85% effective in stopping serious disease and preventing hospitalization across all districts and against a number of changes. The vaccine uses a common cold virus to inject coronavirus proteins into cells and to stimulate an immune response. The company plans to seek emergency use approval from the U.S. Food and Drug Administration (FDA) next week.