Does the vaccine against the novel coronavirus prevent people from transmitting it to others? According to research carried out by Israeli researchers, most likely the answer is yes.
The issue has been considered crucial by health authorities and experts all over the world in order to formulate how fast vaccinating can enable societies to go back to normal life. Clinical trials, which focused on the effectiveness of the vaccine in protecting people from getting infected themselves or developing severe symptoms, did not offer sufficient information in this field.
A team of researchers from several institutions came up with the idea of taking advantage of the fast pace of the vaccination campaign in the country to start looking for some evidence based on real world data.
In the past few months, several studies have shown a correlation between the viral load, which measures the amount of virus in the body, and the ability of a person to infect others.
“We thought that it would be interesting to compare what happened to people over the age of 60, the first age group to be inoculated, to those ages 40-59, who started to be vaccinated later,” Yaniv Erlich, the leading author of the study, told The Jerusalem Post.
Erlich, a former associate professor of computer studies at Columbia University, currently serves as the chief science officer at MyHeritage. Since June, the Israeli company that specializes in DNA tests for ancestry and genetic testing has been operating a lab that processes several thousand coronavirus tests per day in cooperation with the Health Ministry.
Erlich, in collaboration with scholars from some of the leading academic institutions in Israel, including Technion-Israel Institute of Technology and Tel Aviv University, analyzed the viral load of some 16,000 tests returning a positive result between December 1 and January 30.
“We considered four two-week-long windows, knowing that by the end of the period we considered some 80% of people over 60 in Israel had received at least one vaccine, compared to some 30 or 40% of those ages 40-59,” he explained. “Our hypothesis was that the viral load would be lower for individuals in the former group compared to the latter, and our findings confirmed it.”
According to Erlich, while no significant difference between the two groups in the viral load was reported between the beginning of December and mid-January, in the last two weeks, those over 60 presented a viral load lower by 50 to 95%. The scientist highlighted that one of the limits of the study was that they did not know whether the people who took the test had been inoculated nor if they had received one or two shots.
However, this might also mean that if a similar study was to be conducted on people already a week past their second jab, when immunity is considered to kick in, the results could be even more promising.
The study has not been published yet in a peer-reviewed journal. Erlich said that the goal is to achieve this result as well as carry out similar research with more data.