JERUSALEM (Reuters) – Pfizer’s COVID-19 vaccine significantly reduces virus transmission, according to two Israeli studies, which shed light on one of the biggest questions of 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 Germany’s BioNTech reduces infection, including in asymptomatic cases, by 89.4% and in syptomatic cases by 93.7% .
Findings from the pre-published study, not yet peer-reviewed but based on a national database that is one of the most advanced in the world, were first reported Thursday by Israeli news site Ynet and obtained by Reuters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 from Israel’s Sheba Medical Center, published Friday in the medical journal The Lancet, found that among 7,214 hospital staff who received their first dose in January, there was an 85% decrease in symptomatic COVID levels within 15 to 28 days. 19 with an overall reduction. of infections, including asymptomatic cases detected by testing, of 75%.
More research is needed to reach 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 big step towards answering one of the most important questions in fighting the pandemic.
“Whether it’s a 75 percent or 90 percent reduction doesn’t matter – it’s a big drop in transmission,” said Linial. “It means that not only is the vaccinated person protected, the vaccination also protects his or her environment.”
The researchers said further research was needed on asymptomatic transmission in fully vaccinated people because they are less likely to be tested for COVID-19.
Vaccine developers have also said more research was needed on portability. In December, Germany’s BioNTech said it would take three to six months more research.
‘DYNAMIC VIRUS’
A global leader in vaccine rollout, Israel’s universal healthcare and advanced data capabilities have provided a nationwide database that can provide insight into how effective the vaccines are outside of controlled clinical trials.
The Department of Health / Pfizer study analyzed data collected between Jan. 17 and Feb. 6, looking at individuals who were fully vaccinated after receiving their second Pfizer injection.
To date, more than 30%, or 2.8 million of Israel’s nine million residents, have received both doses.
Sheba’s study found that only the first dose of the Pfizers vaccine was 85% effective, possibly sparking debate about the recommended two-dose schedule.
Canadian researchers suggested in a letter published this week that the second dose of Pfizer should be delayed, given the high level of protection from the first injection, to increase the number of people being vaccinated.
The U.S. Food and Drug Administration said in December that those studies showed that the vaccine began to provide recipients with some protection before they received the second injection, but more data would be needed to assess the potential of a single-dose injection .
Pfizer has said alternative vaccine dosing regimens have yet to be evaluated and the decision rests with the health authorities.
Another caveat is that the cohort studied in the hospital was “largely young and healthy,” said Sheba epidemiologist Gili Regev-Yochay.
Unlike Pfizer’s clinical trial, “we don’t have many (staff) over 65 here,” she told reporters. But she also said the Sheba investigation took place during an increase in coronavirus infections in Israel, flooding hospitals with new cases.
Pfizer declined to comment on the data, saying in a statement that it was conducting its own analysis of “the vaccine’s true effectiveness in various locations worldwide, including Israel.”
The findings of both studies compared with the overall efficacy of approximately 95% on a two-dose regimen 21 days apart. Researchers from the Ministry of Health / Pfizer found the vaccine to be effective against the British coronavirus variant, which makes up about 80% of confirmed cases in Israel.
Eran Kopel, an epidemiologist at Tel Aviv University, said the Sheba study was important, but focused on one hospital and a relatively small group of people, so “you couldn’t draw clear epidemiological conclusions from it.”
The data from the Health Department was encouraging, he said, but further research and regular surveys were needed.
“The vaccinations are a very good tool, but this is not the end yet. This is a dynamic virus that has surprised the scientific world with its rapid pace of change and variation, ”he said.
Additional reporting by Dan Williams in Jerusalem; Editing by Jane Merriman and Barbara Lewis