COVID-19 vaccine seems to reduce viral load, transmission – Israeli study

Those who are vaccinated and get infected with the virus present a viral load four times lower than those who were not inoculated, according to an Israeli study recently published in the journal Nature Medicine.

The level of viral load is one of the key elements affecting the ability of a virus carrier to pass on the disease. Therefore, the findings support the notion that those who are jabbed are unlikely to infect others.

The research was done on thousands of patients. It was conducted by the laboratory of Prof. Roy Kishony at the Technion-Israel Institute of Technology in collaboration with the Maccabi Research and Innovation Center, which is headed by Dr. Tal Patalon.

“In this study, we wanted to investigate what happens in the rare case when someone who is vaccinated gets infected,” the Technion’s Dr. Idan Yelin, a lead author of the study together with Matan Levine-Tiefenvrun, told The Jerusalem Post. “In order to do so, we could not just look into whether they are positive or negative. We wanted to look into the number of viral particles they carried.”

Viral load is affected by many elements, including the stage of infection and the age of the patient, he said.

The data from Maccabi allowed the researchers to compare the findings about the patients who were infected after the inoculation with a control group of non-vaccinated patients with similar characteristics.

“There was a very clear difference between the two groups, with the vaccinated patients presenting a viral load four-fold lower than the other ones,” Yelin said.

“The findings present implications on two levels,” he said. “First of all, there is a clear connection between the level of viral load and the severity of the disease. A lower viral load tells us that the immune system is handling the virus better, and the disease is going to be milder.”

Real-world clinical data have repeatedly demonstrated that the vaccine is 99% effective in protecting people from serious symptoms.

“This is completely in line with our findings,” Yelin said.

The second important element is that a lower viral load is likely to be associated with lower transmissibility of the virus.

“There are fewer viral particles in the droplets of whichever type of body fluid you consider,” Yelin said. “For this reason, when someone who was vaccinated gets infected, nonetheless, they are less capable of transmitting the virus.”

The question of whether vaccinated people can infect others has been repeatedly indicated by health experts and officials as a key to deciding how Israel can leave coronavirus restrictions behind.

As more encouraging studies investigating the issue are published, the country might start to dream of a world without masks.