Professor Jacov Lavee receives a fourth dose of coronavirus disease (COVID-19) vaccine as part of a trial in Israel, as Health Ministry is considering offering the second booster to the elderly and immuno-compromised at Sheba Medical Center in Ramat Gan, Israel December 27, 2021. REUTERS/Ronen Zvulun An Israeli heart transplant surgeon on Monday became the first to be jabbed with a fourth dose of the COVID-19 vaccine, as an unprecedented clinical trial kicked off to determine the efficacy of administering a second round of boosters amid the fast spread of the Omicron variant. “It’s one small jab in the shoulder,...