Half of U.S. adults have received their first dose of the COVID-19 vaccine, but cases are still rising, driven by fast-moving variants and spread among younger people who haven’t been vaccinated in hot spots such as Michigan.
Daily cases remain close to the 70,000 mark and hospitalizations are up slightly, while deaths are relatively static, suggesting vulnerable seniors are benefiting from vaccination but the shots haven’t reached enough Americans to hit a tipping point in transmission overall.
The situation underscores the challenge before President Biden as he implores Americans to get vaccinated and create sufficient immunity to crush the spread. Every state is offering the vaccine to any adult, meeting the White House’s goal of widespread eligibility by April 19.
“We remain in a complicated stage. On the one hand, more people in the United States are being vaccinated every single day at an accelerated pace,” said Rochelle Walensky, director of the Centers for Disease Control and Prevention. “On the other hand, cases and hospitalizations are increasing in some areas of the country and cases among younger people, who have not yet been vaccinated, are also increasing.
“We all have a role in turning this tide and to trend our cases down,” she said. “One of the most important things we can do to get back to the things we love is to get vaccinated.”
White House COVID-19 adviser Andy Slavitt said hugs and maskless visits with friends and family should be an incentive, while Mr. Biden insisted there are enough doses available for any adult who wants them.
“We have enough of it, you need to be protected and you need, in turn, to protect your neighbors and your family. So please, get the vaccine.”
Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, said data from Israel, which got a fast start on vaccination, suggest about 40% of the population will need to be fully vaccinated to see changes in transmission.
Right now, about 4 in 10 Americans have received one dose but only a quarter of Americans are fully vaccinated, defined as 14 days after the second dose of the two-shot vaccines from Pfizer-BioNTech and Moderna or the single shot from Johnson & Johnson’s version, which is on hold as scientists study rare blood clots in a handful of recipients.
“It doesn’t appear that we have crossed the threshold of population immunity where we will start to see cases decline,” Dr. Adalja said.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, also cited Israel as a guiding light, given its progress in slashing cases.
“We are not there yet, but we can get there,” he said.
Experts say anywhere from 70% to 90% of the U.S. population must be vaccinated to bring the virus under control completely. Fearful that demand will stall before then, officials are pointing to data showing how effective the shots are in preventing disease.
While no vaccine is perfect, federal officials have received reports of only 6,000 “breakthrough infections” among the 84 million people who are fully vaccinated.
“These vaccines are working. The efficacy we saw in clinical trials is now being shown in the real world,” Dr. Walensky said.
The vaccination campaign began with health care workers before expanding to older Americans and essential workers. Despite the widening campaign, hospitalizations have risen slightly, to about 45,000 nationwide compared to about 41,000 who were taking up beds a month ago.
Deaths tend to rise with hospitalizations, and there are some signs of that happening — about 695 people died per day, on average, in the week ending Saturday, compared to 681 per day during the prior week, Dr. Walensky said.
Yet 80% of American seniors have received at least one dose, and 65% are fully vaccinated, so it’s possible deaths will not surge again. Historically, deaths from the coronavirus have been concentrated among older adults.
Experts hope that metrics will look better soon, as the vaccine campaign chugs along.
“It is still the case that younger individuals who have not been highly vaccinated are driving spread as they are more risk-tolerant and are not vaccinated yet being exposed to more highly contagious variants,” Dr. Adalja said. “To me, cases are not the most important factor — it is hospitalization and hospital capacity. Those metrics, even in states in which hospitalizations may have recently increased, are not concerning and each day are less likely to become concerning as millions are vaccinated.”