US health officials are preparing to authorise a third dose of mRNA Covid-19 vaccines for immunocompromised adults.
Speaking to reporters at the White House on Thursday, Rochelle Walensky, director of the Centers for Disease Control and Prevention, said the Food and Drug Administration had been working with vaccine manufacturers Pfizer and Moderna to “allow boosters” for a small share of adults who are deemed immunocompromised.
Walenksy said the CDC’s advisory committee on immunisation practices would meet on Friday to discuss the issue.
“Emerging data show that certain people who are immune compromised, such as people who have had organ transplants and some cancer patients, may not have had an adequate immune response to just to two doses of the Covid vaccine,” she said, adding: “To be clear, this is a very small population. We estimate it to be less than 3 per cent of adults.”
“At this time, only certain immune compromised individuals may need an additional dose,” Walensky said. She cited a study published this week in The New England Journal of Medicine that showed immunocompromised people produced more antibodies to fight off coronavirus after an additional dose of a mRNA Covid-19 vaccine.
The move comes as cases and hospitalisations from Covid-19 have increased due to the spread of the contagious Delta variant. The US reported 132,384 infections on Wednesday, Walensky said, bringing the seven-day average to about 113,000 cases, a 24 per cent increase from a week ago.
An average of 9,700 patients have been admitted to hospitals with Covid-19 each day over the past week, she said, a 31 per cent increase from a week ago.
The increases have been most notable in parts of the country where vaccinations have lagged, leading some officials to describe the current surge as a “pandemic of the unvaccinated.”
Earlier on Thursday, Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases, told NBC News that “inevitably” everyone would need a third dose of vaccinations.
“No vaccine, at least not within this category, is going to have an indefinite amount of protection,” Fauci said. “Inevitably, there will be a time when we’ll have to give boosts.
“Right now at this moment, other than the immunocompromised, we’re not going to be giving boosters to people,” he added. “But we will be following them very carefully and if they do need it, we’ll be ready to give it to them.”
Fauci’s comments were underscored by Jeff Zients, the White House Covid-19 response co-ordinator, who said the US had enough vaccine supply and the infrastructure to quickly roll out booster shots should they be needed.
The Biden administration announced last month it had secured another 200m doses of the BioNTech/Pfizer Covid-19 vaccine, expanding its total order to 500m, as officials prepare for the next phase of vaccinations, including children under 12 and potential booster shots.
“If and when there is a decision, we are prepared,” Zients said on Thursday. “We have the supply and you will be able to get a booster in a fast and efficient way, if and when the science dictates.”
ABC News on Wednesday published internal CDC documents showing that an estimated 1m Americans had already received unauthorised third doses of Covid-19 vaccines.
Walensky, when asked about the reports, said the health officials were “asking people to follow our guidance, to follow what APIC [Association for Professionals in Infection Control and Epidemiology] will say and the FDA will say in the coming days, several days, and to follow recommendations”.
Additional reporting by Peter Wells in New York