Pfizer vaccine recipients are unlikely to transmit the virus to others, according to the author of an Israeli study.
Participants in the survey developed up to 20 times more antibodies within a week of receiving the second dose of the Pfizer/BioNTech vaccine.
The survey, which reviewed data from 102 of about 1,000 of the Sheba Medical Centre’s medical staff who have received both shots, showed that only two subjects have developed low amounts of antibodies – one of the subjects suffered from a compromised immune system.
There was no explanation for why the second person did not develop antibodies, and the hospital said it was investigating the matter.
The rest – 98 per cent – have developed levels of antibodies that were even higher than patients who have recovered from a serious coronavirus-induced condition, the hospital said in a statement released on Monday.
Professor Gili Regev-Yohai, director of Sheba’s Infectious Disease Epidemiology Unit, said that people who received both doses of the vaccine will most likely not become carriers of the virus and will not spread it further due to the high level of antibodies they have obtained.
It is the first indication that a Covid-19 vaccine may stop transmission.
As of Monday, the hospital had vaccinated some 80 per cent of its employees with the first dose – a total of 7,106 individuals – and 4,484 with the booster shot.
“The results of the survey are consistent with Pfizer’s experiment and even exceeded expectations,” Prof Regev-Yohai said.
While people who were sick and recovered are not yet eligible to receive the Pfizer vaccine in Israel, if further research shows that the vaccine produces improved immunity, it is possible that they will be inoculated in a second phase, at least with the booster shot, she said.
It is one of the first studies conducted outside of Pfizer’s own trial into the efficacy of the vaccine.
Israel leads the world in inoculations per capita, having surpassed the two million mark over the weekend.