Some countries shorten COVID-19 booster timelines in face of Omicron surge

Dec 20 (Reuters) -  ...

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 course of COVID-19 vaccines - typically given in two doses - is not enough to halt infection from the Omicron variant, but a booster shot may help....

Research from southern Africa and the UK shows that the variant is spreading very quickly, prompting forecasts that it will soon outpace Delta in several countries. Scientists are also trying to determine how severe cases of Omicron are.

Many countries, including the United States, earlier this year authorized booster doses at six months after a person completes vaccination. This month, South Korea, the United Kingdom and Thailand cut that interval to three months. Belgium has lowered it to four months.

France, Singapore, Taiwan, Italy and Australia have decreased their booster wait time to five months.

Some countries, including the United States, South Africa and Germany, have stuck to the six-month booster schedule.

Finland has recommended a three-month booster timeline for at-risk groups, saying it does not believe shortening the time for the general population will slow rising hospitalizations.

Spain and Lithuania are also so far offering boosters only to people with weak immune systems, the elderly or vulnerable, while India has not decided on a booster campaign. The World Health Organization, which had told rich countries to prioritize sending first COVID vaccine doses to the developing world, has become more open to boosters in light of rising cases. ...