Biden officials to get key data on new Covid booster’s effectiveness

Yet it remains unclear how significant that upgrade will be. An earlier pair of small studies released in recent weeks found little relative additional benefit, and health officials have internally sought to temper expectations that the booster will do a significantly better job in guarding against the virus.

The results are also unlikely to alter the White House’s core message that Americans who get the booster shot are far more protected against Covid than those who go without any vaccination.

“Virtually every Covid death in America is preventable,” President Joe Biden said in late October, as he got the updated booster shot. “Almost everyone who will die from Covid this year will not be up to date on their shots or they will not have taken Paxlovid when they got sick.”

Pfizer did not respond to a request for comment. The White House declined to comment.

Pharmaceutical company Moderna, which also developed an updated booster, is not expected to submit full data on its vaccine to the administration until later this month, the people with knowledge of the matter said.

The new data comes roughly two months after the Biden administration rolled out the updated vaccines, citing the need to safeguard Americans ahead of an expected winter Covid surge. The boosters were tailored to better protect against the Omicron strains driving the majority of cases — a development that Joe Biden hailed as “a serious, giant step forward.”

Still, the administration’s vaccination campaign has progressed slowly, with federal estimates showing fewer than 9 percent of those eligible have received an updated booster so far. Across the country, health officials have blamed the low uptake on a combination of public apathy toward the pandemic, a lack of government resources to promote the shots and a deepening partisan divide over the Covid response.

Biden health officials had hoped that initial data would show the boosters perform significantly better than the original vaccines, providing a fresh jolt that would convince people to urgently seek out the vaccines.

After early studies conducted by academic researchers found limited improvement, Biden health officials reached out to outside public health experts to help downplay the results and urge patience for Pfizer’s fuller findings, the people with knowledge of the matter said. Within the administration, health officials have quibbled with the studies’ small sample sizes — predicting that Pfizer’s results are more likely to show a modest improvement compared with the original vaccines.

Officials also anticipate that the boosters could provide better protection against newer variants increasingly circulating within the U.S. — a prospect that Pfizer is still studying.