COVID booster jabs provide 90% protection against hospitalisation in the over-65s for at least three months, UK scientists have said.
It means there is “no immediate need” for a fourth jab to be administered to vulnerable people, the UK Health Security Agency (UKHSA) said.
Older adults who have not had a booster suffer a significant loss of protection, however.
With two doses, the figure drops to 70% after three months and 50% after six months, the UKHSA said.
The “timing and need for further booster doses will continue to be reviewed as the data evolves”, scientists added.
For the moment, priority will be given to “rolling out first booster doses to all age groups”.
Protection against mild symptomatic infection is more short-lived, the UKHSA said, and “drops to around 30% by about three months”.
Professor Wei Shen Lim, who sits on the Joint Committee on Vaccination and Immunisation, said “high levels” of protection were being provided “even for the most vulnerable older age groups”.
He added: “The data is highly encouraging and emphasises the value of a booster jab.
“With Omicron continuing to spread widely, I encourage everyone to come forwards for their booster dose, or, if unvaccinated, for their first two doses, to increase their protection against serious illness.”
Just over 35 million people have now had a third vaccine, meaning 61% of people aged 12 and over have been boosted, according to the latest daily official figures.
It comes as Health Secretary Sajid Javid warned that hospital admissions from coronavirus were rising and that the NHS was facing a “rocky few weeks ahead” as he urged people in the UK to get their boosters.