About 2 million people received Pfizer COVID-19 booster shots this week and another 1 million people are scheduled for one in the next couple of weeks, the White House announced Friday.

“That’s a very strong start,” White House COVID-19 Response Coordinator Jeff Zients said in a virtual briefing with reporters. The robust demand comes despite confusing messages before the rollout and data suggesting two doses of the mRNA vaccines offer durable protection against severe disease for most Americans. 

Zients also announced 8,000 onsite clinics will open in the coming weeks focused on booster shots and flu shots, including at nursing homes and assisted living facilities. 

Walgreens and CVS, the federal government’s private partners on the vaccine rollout in long-term care facilities last winter, did not immediately reply to requests for comment. 

Demand has been spurred by thousands of texts, emails and calls from pharmacies and public health departments to eligible people, Zients said. Maryland conducted 250,000 calls. 

Vaccine effectiveness against infection can fall by 1 percent to 5 percent five months after a second shot, according to a Food and Drug Administration analysis of a Pfizer study. But the vaccine remains durable against serious disease and death for a longer period.

Meanwhile, Biden health officials acknowledged the urgency of vaccinating eligible people who have yet to receive their first vaccine. 

Infectious diseases experts agree that reaching the unvaccinated is the most important obstacle to ending the pandemic. 

“There are still places around the country where far too many individuals remain unvaccinated and many states where the vaccination rate is less than 50 percent,” Centers for Disease Control and Prevention Director Rochelle Walensky said. 

About 185 million Americans have received a vaccine, Walensky said, while 70 million eligible people have yet to get a first shot. 

Roughly 180,000 people have died since the spring, after FDA authorized three vaccines.

Zients touted high vaccination rates at places that have implemented vaccine requirements in the three weeks since President Joe Biden announced a new forthcoming Occupational Safety and Health Administration rule would demand that large businesses put mandates in place.

The number of job postings requiring COVID-19 vaccination has increased by 20-fold, Zients said, citing data from LinkedIn.