Vials with labels of Pfizer-BioNTech and Moderna coronavirus (COVID-19) vaccine can be seen in this illustrative photo taken on March 19, 2021.
Given Ruvic | Reuters
Given Ruvic | Reuters
The following is a summary of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for Covid-19.
Moderna’s vaccine might be best against Delta
Pfizer and BioNTech’s mRNA vaccine may be less effective than Moderna’s against the delta variant of the coronavirus, according to two reports published Sunday on medRxiv ahead of peer review. In a study of more than 50,000 patients from the Mayo Clinic Health System, researchers found that Moderna’s vaccine efficacy against infection had fallen to 76% in July – when the delta variant was predominant -om 86% in early 2021. During the same period, the effectiveness of the Pfizer / BioNTech vaccine fell to 42% from 76%, according to the researchers. While both vaccines remain effective in preventing hospitalization from Covid, a Moderna booster may soon be needed for anyone who received the Pfizer or Moderna vaccines earlier this year, said the analytics firm’s Dr Venky Soundararajan. Massachusetts Data Center, which led the Mayo Study.
In a separate study, residents of nursing homes for the elderly in Ontario produced stronger immune responses – especially against disturbing variants – after the Moderna vaccine than after the Pfizer / BioNTech vaccine. Seniors may need higher vaccine doses, boosters and other preventative measures, said Anne-Claude Gingras of the Lunenfeld-Tanenbaum Research Institute in Toronto, which led the Canadian study. When asked to comment on the two research reports, a Pfizer spokesperson said, “We continue to believe that a third booster dose may be needed within 6 to 12 months of full vaccination to maintain the highest levels of protection.
Covid-19 breakthrough more likely months after vaccination
People who received their second dose of the Pfizer / BioNTech vaccine five months or more ago are more likely to test positive for Covid-19 than people who were fully vaccinated less than five months ago, suggest new data. Researchers studied nearly 34,000 fully vaccinated adults in Israel who were tested to see if they had a breakthrough case of Covid-19. Overall, 1.8% tested positive. At all ages, the chances of testing positive were higher when the last vaccine dose had been received at least 146 days earlier, the medRxiv research team reported Thursday before the peer review. In patients over 60 years of age, the chances of a positive test were almost three times higher when at least 146 days had passed since the second dose. Most of the new infections have been seen recently, said co-author Dr Eugene Merzon of Leumit Health Services in Israel. “Very few patients required hospitalization, and it is too early to assess the severity of these new infections in terms of hospitalization, need for mechanical ventilation or mortality,” he added. “We plan to continue our research. “
Ovarian egg sacs not damaged by Covid-19 antibodies
The sacs in the ovaries where eggs are stored are not damaged by Covid-19 antibodies, whether those antibodies are the result of infection or vaccination, suggests a small study. Israeli researchers analyzed the fluid in the ovarian sacs, or follicles, of 32 women whose eggs were taken to be fertilized with sperm in a test tube. Fourteen women had not been vaccinated against or infected with the coronavirus. The others had either recovered from Covid-19 or received the Pfizer / BioNTech mRNA vaccine, and in both of these groups, researchers saw antibodies to the virus in follicular fluid. There was no difference between the groups in the ability of the follicles to make female sex hormones, nourish and nourish the egg so that it forms a good quality embryo, and release the egg during ovulation. . There was also no difference in “the rate of good-quality embryos” among the eggs retrieved from each patient, “said Dr Yaakov Bentov of Hadassah-Hebrew University Medical Center in Jerusalem, co. -author of a report published on Saturday in Human Reproduction.