UK to offer fourth coronavirus vaccine shot to people 75 and over

The United Kingdom will offer a fourth dose of COVID-19 vaccine to certain vulnerable populations this spring, health officials there said Monday.

The U.K will offer the additional shot to people aged 75 and over, as well as people in care homes for older adults and people 12 and over who are immunosuppressed.

"We know immunity to COVID-19 begins to wane over time," U.K. Health Secretary Sajid Javid said. "That's why we're offering a spring booster to those people at higher risk of serious COVID-19 to make sure they maintain a high level of protection. It's important that everyone gets their top-up jabs as soon as they're eligible."

The additional shot will be offered six months after the person's last dose, and comes as the country prepares to lift all COVID-19 restrictions. U.K. officials noted most of the country's most vulnerable residents received their previous shot in September or October.

A broader booster shot campaign, for additional higher-risk groups, could occur in the fall.

The move from the U.K. could play into the debate in the United States over whether an additional shot is needed.

So far, U.S. officials are not recommending fourth doses, except for immunocompromised people, though they say they are still studying the question and gathering data.

A Centers for Disease Control and Prevention (CDC) study earlier this month found a third shot's protection against hospitalization waned somewhat from 91 percent after two months to 78 percent after four months.

CDC Director Rochelle Walensky said in an interview on the "In the Bubble with Andy Slavitt" podcast released Monday that 78 percent protection is "still pretty high."

"We're still doing pretty well at 78 percent in terms of hospitalization," Walensky said. "Now, we're going to continue to follow this. This was our first data point."

"As we follow those data, we'll continue to make recommendations and see if boosters are needed for that population," she added.