Israel aiming to launch fourth COVID shot trial

Israel’s largest hospital is expected to launch a trial to determine the benefits of receiving a fourth dose of the Pfizer coronavirus vaccine, The Jerusalem Post confirmed.

The trial was first reported on by KAN News. It will be run by Sheba Medical Center at Tel Hashomer under the guidance of Dr. Gili Regev-Yochay, director of the Infectious Disease Epidemiology Unit at the hospital. It will look to see how much an additional shot raises a person’s antibody levels.

The volunteers, likely hospital workers who are already part of an ongoing antibody study at the hospital, will be tested several times before and after the fourth dose. The exact number of participants is still fluid.

The hospital has applied to the Health Ministry’s Helsinki Committee to carry out the trial and is still waiting for final approval.

Health officials met earlier this week to examine whether a fourth dose should be administered already, in light of data showing that two doses are largely not effective against the Omicron variant and three doses are less protective than they were against Delta. However, they decided against moving forward with another shot – even for immunocompromised people.

People receive a third dose of the Sinopharm vaccine against the coronavirus disease (COVID-19) at the Belgrade Fair vaccination center in Belgrade, Serbia, August 25, 2021. (credit: REUTERS/ZORANA JEVTIC)

Israel was the first in the world to administer a third shot of the vaccine. Administering a fourth, even via a clinical trial, would be largely unprecedented, although the US Centers for Disease Control and Prevention updated its guidelines in late October saying that moderately or severely immunocompromised people who receive three shots as their primary dose can receive a booster dose, too, for a total of four COVID-19 vaccine doses.

An official close to the project said the hospital does not expect recruitment for the trial to be easy, given the amount of vaccine fatigue in the country and the recent revelation that the original vaccine may not work as well against newer variants.

Both Pfizer and Moderna have said they are looking into updating their vaccines to increase their efficiency against the Omicron variant.