In many parts of the United States, it worked. Millions lined up for shots and, as the vaccination rate increased nationwide, daily COVID-19 cases, hospitalizations and deaths dropped.
But the focus on vaccines accompanied a decline in COVID-19 testing, mixed messages on masking, and a failure to anticipate potent anti-vaccination sentiment, misinformation and the virus' own ability to mutate rapidly into more formidable variants, some critics said.
"To protect the country from COVID, you need to have multiple strategies," said Dr. Peter Chin-Hong, an infectious disease specialist and professor at the University of California, San Francisco. "We jumped on the vaccine bandwagon and excitement at the expense of other core strategies in the pandemic."
COVID-19 cases are rising in nearly 90 percent of jurisdictions in the United States, according to the Centers For Disease Control and Prevention (CDC), with outbreaks in areas with low vaccination rates.
The new spike in cases has clouded what had been a full-steam ahead economic recovery, and could be especially risky if consumers become more cautious and spending slows as pandemic-era unemployment benefits, rent moratoria and other supports begin to expire.
"Vaccination remains the most important thing we can do to prevent the spread of the virus, and so we need to be pulling all levers to support vaccination," said Carole Johnson, the White House's coordinator on COVID-19 testing.
White House officials said Biden's $1.9 trillion pandemic relief package, known as the American Rescue Plan, invested billions of dollars into COVID testing for schools and people who are uninsured.
UNDERESTIMATING ANTI-VAX MOVEMENT
Americans' refusal to take free, widely available vaccines that shield them from serious illness and death has confounded the Biden White House.
While vaccines largely protect people from contracting and transmitting the Delta variant, there are rare cases where fully vaccinated people get the virus and may be able to pass it on.
Biden has increasingly referred to the pandemic as one of the unvaccinated.
"It's the just unfortunate conflation of two things, and that is a virus that has evolved to be extraordinarily efficient in transmitting from person to person ... superimposed upon an almost inexplicable resistance to vaccinations," top U.S. infectious disease expert Anthony Fauci told Reuters.
Fauci said that the federal government would rely at least in part on vaccine mandates from schools and businesses for their students and employees to spur lagging vaccination rates.
"If you can't get people on their own volition ... to do what is important for their own health and for that of the country, then you talk about pressure. And pressure is local mandates," he said.
About 163.3 million people, or 49.2% of the total U.S. population, have been fully vaccinated, according to the CDC. The agency's data shows a slight uptick in the vaccination rate in recent weeks. Testing has increased as well.
Many experts had suggested that vaccinating 70% or more of the population could help curb COVID-19 transmission through so-called herd immunity, when combined with people who developed immunity following an infection.
But the ability of the coronavirus to mutate quickly into new, highly transmissible variants has cast doubt on whether herd immunity can be achieved.
As of July 27, the United States was on pace to vaccinate 70% of the entire population by Dec. 16, far later than many developed economies, Reuters analysis shows.
Politics is at least partly to blame.
Some Republican lawmakers have refused to say whether they have taken a vaccine and opposed Biden's efforts to get more people vaccinated.
The spread of misinformation sparked Senate Minority Leader Mitch McConnell, one of the Biden administration's toughest policy opponents, to plan pro-vaccination commercials funded with money from his re-election campaign in his home state of Kentucky, the 79-year-old lawmaker told Reuters.
Anti-vaccination sentiment did not come out of the blue. Reuters/Ipsos polling showed hesitancy was ripe through 2020 and early 2021.
The White House has repeatedly pushed back against misinformation, targeting social media platforms in particular.
Dr. Peter Hotez, a vaccinologist and dean of the National School of Tropical Medicine at Baylor College of Medicine, said the Biden administration's acknowledgement of the "terrible impact" of the anti-vaccine movement was important, but he said the government could do more.
"Anti-science is arguably one of the leading killers of the American people, and yet we don't ... treat it as such. We don't give it the same stature as global terrorism and nuclear proliferation and cyber attacks," he said.
The Kaiser Family Foundation said earlier this month its surveys showed Democrats were much more likely to say they have been vaccinated than Republicans.
Former Trump administration officials argue Biden should have given his predecessor some credit for pushing speedy development of the vaccines, to boost vaccination rates among his supporters.
Trump, who has continued to claim falsely that he won the 2020 election, is the only living president who has not participated in public service announcements to encourage people to take the vaccine.
The White House has rejected criticism that it did not engage Trump more.
MASKS OFF AS A REWARD
The Biden administration sought to create incentives for people of all political stripes by emphasizing, in line with CDC guidance updated in the spring, that those who received their shots could move around without covering their mouth and nose.
"If you are fully vaccinated, you no longer need to wear a mask," Biden said in a May 13 speech in the White House Rose Garden.
But critics say the guidance on mask-wearing has been confusing.
On Tuesday the CDC partially reversed course, encouraging vaccinated Americans to go back to wearing masks in indoor public places in regions where the Delta variant is rapidly spreading.
"I honestly think it's like trying to put toothpaste back in the tube," said Carlos del Rio, a professor of medicine and infectious disease epidemiology at Emory University in Atlanta, referring to getting people to mask up again.
Meanwhile, as the Delta variant spreads, a lack of testing makes it harder to track asymptomatic cases.
Eric Topol, a genomics expert and director of the Scripps Research Translational Institute in La Jolla, California, said rapid testing would help vaccinated people check themselves before traveling or dining in a restaurant.
"That's blatantly missing," he said.
Biden's American Rescue Plan invested $4.8 billion for testing of uninsured people and $10 billion for testing in schools, the White House said.
"Testing has tended to ebb and flow with cases," said Johnson, the testing coordinator. "Because ... we have worked so hard to get people vaccinated, there were not as many people seeking testing."
In 2020, U.S. regulators worked on overdrive to authorize dozens of COVID-19 tests, including low cost, rapid antigen tests, with the goal of boosting national testing capacity to some 200 million per month by the end of 2020.
But demand for tests declined as vaccination rates increased. Earlier this month, Abbott Laboratories said it laid off 400 workers at two of its test-making facilities in response to falling demand.
(Additional reporting by Carl O'Donnell and Howard Schneider; Editing by Heather Timmons, Caroline Humer and Grant McCool) ((email@example.com; +1 202 898 8300; On Twitter: @jeffmason1; Reuters Messaging: firstname.lastname@example.org))