JERUSALEM (Reuters) – Pfizer’s COVID-19 vaccine significantly reduces virus transmission, found two Israeli studies and sheds light on one of the biggest questions in the global effort to destroy the pandemic.
Data analysis in a study by the Israeli Ministry of Health and Pfizer Inc. found that the Pfizer vaccine developed with the BioNTech of Germany reduces infection, including in asymptomatic cases, by 89.4% and in symptomatic cases by 93, 7%.
Findings from the pre-published study, which has not yet been peer-reviewed but based on a national database that is one of the world’s most advanced, were first reported by the Israeli news website Ynet late Thursday and were obtained by Reuters on Friday.
Pfizer declined to comment and the Israeli Ministry of Health did not respond to a request for comment.
A separate study by the Israeli Sheba Medical Center, published in The Lancet Medical Journal on Friday, found that among 7,214 hospital staff who received their first dose in January, there was an 85% reduction in symptomatic COVID-19 within 15 to 28 days with an overall reduction. infections, including asymptomatic cases detected by testing, of 75%.
More research is needed to draw a definitive conclusion, but the studies are among the first to suggest that a vaccine can stop the spread of the new coronavirus and not just prevent people from getting sick.
Michal Linial, a professor of molecular biology and bioinformatics at the Hebrew University of Jerusalem, said the findings were a major step in answering one of the key questions in combating the pandemic.
“Whether it’s a 75 or 90 percent reduction, no matter, it’s a big drop in transfer,” Linial said. “This means that the individual is not only protected, but that the vaccination also protects his or her environment.”
The researchers said further investigation into asymptomatic transmission among people who have been fully vaccinated is necessary because they are less likely to be tested for COVID-19.
Vaccine developers also said more research on transmissibility was needed. In December, the BioNTech of Germany said it would take three to six months more study.
‘DYNAMIC VIRUS’
Israel’s universal healthcare and advanced data capabilities have provided a nationwide database that can provide insight into how effective the vaccines are beyond controlled clinical trials.
The Ministry of Health / Pfizer study analyzed the data collected between January 17 and February 6 and looked at individuals who were fully vaccinated after receiving their second Pfizer shot.
To date, more than 30%, or 2.8 million of Israel’s nine million people, have received both doses.
Sheba’s study found that only the first dose of Pfizer’s vaccine was 85% effective, possibly triggering a debate over the recommended dose for two doses.
Canadian researchers suggested in a letter published this week that the second dose of Pfizer be delayed, given the high level of protection from the first shot to increase the number of people vaccinated.
The U.S. Food and Drug Administration said in December that data from the trials showed that the vaccine had begun to provide some protection to recipients before they received the second shot, but more data would be needed to address the potential of a single dose. shot to determine.
Pfizer said the alternative dosing systems of the vaccine have not yet been evaluated and that the decision rests with the health authorities.
Another warning is that the group studied in the hospital was mostly young and healthy, said Gili Regev-Yochay, Sheba epidemiologist.
Unlike with Pfizer’s clinical trial, ‘we do not have many (staff) here older than 65’, she told reporters. But she also said the Sheba study took place during an increase in coronavirus infections in Israel, which flooded hospitals with new cases.
Pfizer declined to comment on the data, saying in a statement that it was conducting its own analysis of “the reality of the vaccine in various parts of the world, including Israel”.
Both studies’ findings are comparable to the overall efficacy of approximately 95% in a two-dose regimen with 21 days apart. Researchers from the Ministry of Health and Pfizer have found that the vaccine is effective against the British coronavirus variant, which accounts for about 80% of Israel’s confirmed cases.
Eran Kopel, an epidemiologist at Tel Aviv University, said the Sheba study was important, but it focused on one hospital and a relatively small group of people, so one could not draw clear epidemiological conclusions from it. ‘.
The data from the Ministry of Health was encouraging, he said, but further research and regular surveys are needed.
‘The vaccinations are a very good tool, but it’s hardly the end. It is a dynamic virus that has surprised the scientific world with its rapid pace of change and diversity, ”he said.
Additional reporting by Dan Williams in Jerusalem; Edited by Jane Merriman and Barbara Lewis