LONDON — The UK Health Security Agency recommended against giving a fourth COVID-19 vaccine to the most vulnerable, stating that the need for further doses would continue to be reviewed.

Priority should continue to be given to rolling out first booster doses to all age groups, the government agency said.

"The current data shows the booster dose is continuing to provide high levels of protection against severe disease, even for the most vulnerable older age groups," said Professor Wei Shen Lim, the JCVI’s chair of COVID-19 immunization, in a statement.

"For this reason, the committee has concluded there is no immediate need to introduce a second booster dose, though this will continue to be reviewed."

While the booster dose protects against severe disease, its protection against infection is "more short-lived", declining to around 30% after three months, the agency said.

Protection against severe disease remained at 90% for people aged 65 and over three months after a booster jab.

Pfizer’s CEO Albert Bourla said earlier in December that a fourth dose of a COVID-19 jab may be needed due to the emergence of the more transmissible Omicron variant.

Israel this month began giving fourth booster doses to citizens aged 60 and over and medical staff. — Euronews