US works with vaccine makers on booster dose for some - CDC director

The US Food and Drug Administration is working with vaccine makers Pfizer Inc and Moderna Inc to allow certain vulnerable people to receive a third booster shot of their Covid-19 vaccines to improve their immune response, the director of the US Centers for Disease Control and Prevention said on Thursday.

Speaking at a White House Covid-19 press briefing, CDC Director Rochelle Walensky said the shots would be available to certain people who are moderately and severely immune compromised, such as people who have had organ transplants and some cancer patients. She estimated the group of vulnerable people was less than 3% of adults.

"This action is about ensuring our most vulnerable, who may need an additional dose to enhance their biological responses to the vaccines are better protected against Covid-19," Walensky said.

The CDC's Advisory Committee on Immunization Practices will meet on Friday to discuss this issue and offer recommendations.

Top US infectious disease official Dr. Anthony Fauci said US officials do not believe elderly or others who are not immunocompromised need another vaccine dose at this moment.

Still, he said the government was evaluating the necessity of booster shots on a day-by-day basis.

"It's a true statement that we believe sooner or later you will need a booster for durability of protection," Fauci said.

Cases and hospitalizations have surged across the country in the past month. Some hospitals in Arkansas, Florida, Louisiana and Mississippi have run out of beds, and the outbreak is spreading beyond the epicenter in the US South to Oregon and Washington state.

Some other countries, such as Israel and Germany, plan to or have already administered third shots to elderly or vulnerable people to try to slow the spread of the contagious Delta variant of the coronavirus.