econd coronavirus vaccine booster shot for people with weakened immune systems, with a final decision on wider usage still pending.
An Israeli hospital administered fourth shots to a test group of health workers on Monday, in what it called the first major study into whether a second round of boosters will help contend with the Omicron variant.
Meanwhile, the number of daily new COVID-19 cases worldwide has crossed one million for the first time since infections were first recorded two years ago, according to a tally. The pandemic began in March 2020.
New infections in the United States have soared to their highest level on record, largely driven by the highly contagious Omicron coronavirus variant.
Australia also hit a new record on Thursday as it narrowed its definition of close contacts of coronavirus cases and relaxed requirements for COVID-19 tests, in a bid to relieve pressure on testing sites.
