Some countries shorten booster timeline to five months amid omicron spread

Several countries are moving up their COVID-19 booster shot eligibility timelines amid a spike in cases due to the omicron variant, Reuters reported.

The standard timeline for booster shots in many countries, including the United States, has been six months after the conclusion of the first round of vaccinations.

As the new highly contagious variant continues to spread and cases surge, France, Singapore, Taiwan, Italy and Australia have decided to move their booster shot inoculation period ahead to five months. Belgium will now allow booster shots four months after initial vaccination, and South Korea, the United Kingdom and Thailand have decreased the time frame to three months, according to Reuters.

The U.S. so far has stuck with its six-month recommendation.

Many countries are adjusting their guidance, as some reports suggest the newest variant, which was first detected in South Africa, is more likely to evade preexisting immunity compared than other variants.

Some scientists are expressing concern that advancing the booster timeline could affect the vaccine’s efficacy, however.

“In general for multiple-dose vaccines … the immune system works better if it has time to mature,” William Schaffner, an infectious diseases expert from the Vanderbilt University School of Medicine, told Reuters.

Experts continue to stress that vaccination is the best line of defense against the aggressive new variant. 

“The vaccinated and those who are boosted I believe will be relatively well protected, at least against severe disease,” Anthony Fauci said last week.