LONDON — UK government advisers have recommended against giving a fourth dose of COVID-19 vaccine to nursing home residents and people over 80 because data shows that a third shot offers lasting protection against admission to the hospital.

For people over 65, protection against hospitalization remains at about 90% three months after the third dose, according to data compiled by the U.K. Health Security Agency.

As a result, the Joint Committee on Vaccination and Immunization on Friday advised the government that there was no need to offer a fourth dose, or second booster, to vulnerable people at this time. Instead, the government should focus on giving a third dose to as many people as possible to boost protection against the highly transmissible omicron variant.

“The current data show the booster dose is continuing to provide high levels of protection against severe disease, even for the most vulnerable older age groups,” said Prof. Wei Shen Lim, the committee’s chair. “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.”

The U.K. is racing to offer booster shots to adults across the country after research showed that two doses were not enough to protect people from omicron. The variant has fueled a surge in coronavirus infections and hospitalizations.

The number of people in the U.K. hospitalized with COVID-19 rose to 18,454 on Thursday, more than double the figure two weeks earlier.

Rising staff absences at U.K. hospitals have already prompted the military to provide backup to beleaguered doctors and nurses.

More than 39,000 staff members at hospitals in England were off work for reasons related to COVID-19 on Jan. 2, up 59% from the previous week, according to NHS England.

The respected trade publication, the Health Service Journal, said staff absences across the entire National Health Service, including mental health trusts and other areas, may be as high as 120,000.