The COVID-19 vaccine developed by Pfizer and BioNTech is 95 percent effective at protecting against infection, large human trials found, but there is no conclusive evidence yet that the vaccines prevent transmission of the new coronavirus. "Early findings from Oxford/AstraZeneca revealed its vaccine could have some effect on transmitting the virus, while similar results have also been reported by Pfizer/BioNTech," Reuters reports. But "scientists do not yet know whether COVID-19 vaccinations will reduce transmission because this was not tested in the trials."
A new study from Israel's Sheba Medical Center in Tel Hashomer suggested that the Pfizer vaccine does, in fact, reduce transmission. The small study of 102 medical workers found that after the second dose of the vaccine, 100 of the subjects had significantly higher levels of antibodies than even people who recovered from severe COVID-19 infections, The Jerusalem Post reports.
"The results of the survey are in line with Pfizer's experiment and even better than expected," said Prof. Gili Regev-Yochay, director of Sheba's Infectious Disease Epidemiology Unit. "I expect that the survey results of the other employees participating will be similar. There is certainly reason for optimism." It isn't clear how long immunity will last, and the results are preliminary, but Regev-Yochay said it appears to her that fully vaccinate people won't shed the virus, meaning they won't pass it on to others.
"People who have received both doses of the vaccine have levels of antibodies ranging from six to 59," Regev-Yochay said. "These are high values, and it's encouraging and reasonable to assume that these people will not be carriers or contagious, although that is still not a direct conclusion." Israel is the first country to have vaccinated nearly a quarter of its population, making it a valuable resource for vaccine developers and public health experts.