An Israeli hospital administered fourth Covid-19 vaccine doses to a test group of health workers today, in what it called the first major study into whether a second round of boosters will help contend with the fast-spreading Omicron variant.
Results of the trial, likely to be closely watched internationally, will be submitted to Israel's health ministry in about two weeks, said a spokesperson for Sheba Medical Centre near Tel Aviv.
Israel was the fastest country to roll out initial vaccinations a year ago, and became one of the first to launch a booster programme after observing that immunity waned over time.
Today, the Health Ministry said it was shortening the time between offering the second and third doses of Covid-19 vaccine to three