JERUSALEM, Undefined (AFP) — Fourth doses of the Pfizer and Moderna vaccines against Covid-19 are only “partially” effective for the Omicron variant of the virus, the authors of an Israeli trial said Monday. A team from Sheba Medical Center near Tel Aviv began conducting a trial in December on fourth doses of coronavirus vaccines, inoculating 154 hospital personnel with Pfizer jabs and 120 other volunteers with Moderna doses. Preliminary results of the trial “have shown […]