As Omicron threatens a surge, some countries shorten booster timelines

Half a dozen laboratory studies have shown that an initial course of Covid vaccines - typically given in two doses - is not enough to halt infection from Omicron variant, but a booster shot may help

A growing number of countries are reducing the wait time for COVID-19 vaccine boosters from six months to as few as three in a bid to ward off a new surge in infections from the Omicron variant.
 

They are reacting to early evidence suggesting that Omicron is spreading faster than its predecessor, Delta, and is more likely to infect people who were vaccinated or had COVID in the past. Some scientists, however, say that giving boosters too soon could compromise the level of longer-term vaccine protection.

While data remains limited, half a dozen laboratory studies have shown that an initial