Half of all Americans aged 18 or older have now gotten at least one shot in the arm of a COVID-19 vaccine, the U.S. Centers for Disease Control and Prevention announced Sunday.

The agency said that almost 130 million people — 50.4% of the U.S. adult population — have received at least one dose of vaccine, while almost 84 million adults, or nearly a third (32.5%), are fully vaccinated.

For many, the protection that comes with immunization has meant a relaxation of rules and precautions that have separated loved ones for more than a year.

“It’s a little emotional. I haven’t been able to see my grandmother in a year and a half almost,” Alabama resident Amanda Grimsley, 35, told the Associated Press. “And that’s the longest my entire family has ever gone without seeing her. And we’ll be seeing her in mid-May now.”

But even as the United States passed a milestone in the numbers of citizens vaccinated, billions more people around the globe lack access to vaccines, and the global COVID-19 death count surpassed 3 million, the AP reported.

In the United States, efforts to vaccinate are now beginning to shift from getting shots into the arms of those who were eager for immunization, to trying to convince the many who are still hesitant.

Politics and geography remain key factors in vaccine acceptance. According to a poll conducted in late March by the Associated Press-NORC Center for Public Affairs, 36% of Republicans said they will probably or definitely not get vaccinated, versus 12% of Democrats.

And while less than one-quarter of people living in cities say they are hesitant about getting a shot, that number rises to one-third of Americans living in rural areas, polling found.

Nevertheless, overall acceptance of the vaccines is on the rise. According to the AP-NORC poll conducted in January, 67% of Americans said they’d be willing to get a COVID-19 vaccine, but that number has risen to 75% in the latest AP-NORC poll.

Race also seems to be playing less of a role: In January, an AP-NORC poll found 41% of Black Americans, 34% of Hispanic Americans and 31% of white Americans saying they would probably or definitely not get vaccinated. However, the latest poll found those numbers had fallen to 24%, 22% and 26%, respectively.

Johnson & Johnson COVID vaccine in limbo after clotting reports

In the meantime, the fate of Johnson & Johnson’s coronavirus vaccine hangs in the balance after a government advisory committee said it needed more time and evidence to determine whether unusual, but severe, blood clots seen in a handful of people were caused by the vaccine.

So far, only six clotting cases have been officially reported out of more than 7 million shots given of the one-dose vaccine. But on Tuesday, U.S. health officials recommended a pause in J&J vaccinations.

On Wednesday, advisers to the CDC held an emergency meeting to look at the evidence and decided they did not have enough information or time to recommend how to proceed, the AP reported. A second emergency hearing has been scheduled for next week.

But some vaccine specialists who watched the deliberations said the public shouldn’t have to wait for more advice.

The CDC advisors stressed they need to proceed carefully.

“I continue to feel like we’re in a race against time and the variants, but we need to [move forward] in the safest possible way,” said CDC adviser Dr. Grace Lee, of Stanford University, who was among those seeking to postpone a vote on the vaccine, the AP reported.

Authorities have studied the clots for only a few days and have little information to judge the shot, said fellow CDC adviser Dr. Beth Bell, from the University of Washington, the AP reported.

“I don’t want to send the message [that] there is something fundamentally wrong with this vaccine,” Bell said. “It’s a very rare event. Nothing in life is risk-free. But I want to be able to understand and defend the decision I’ve made based on a reasonable amount of data.”

One of the most worrying things about the clots is that they are atypical and require different treatment. They occur in unusual places, such as in veins that drain blood from the brain, and in people with abnormally low levels of clot-forming platelets, the AP reported. The six cases raised an alarm bell because that number is at least three times more than experts would have expected to see of more typical clots, said the CDC’s Dr. Tom Shimabukuro.

“What we have here is a picture of clots forming in large vessels where we have low platelets,” Shimabukuro explained to the AP. “This usually doesn’t happen,” but it is eerily similar to European reports of clotting with the AstraZeneca vaccine.

The J&J clotting cases in the United States were all among women younger than 50. In Europe, most but not all cases following AstraZeneca vaccinations have been among women under 60, leading different countries to deploy that vaccine in more limited ways.

Also, a 25-year-old man experienced a similar clot during U.S. testing of J&J’s vaccine, something the government scrutinized at the time but could not link to the shot. And on Wednesday, the company also brought to the CDC’s attention a woman whose clot did not occur in the brain, the AP reported. So far, the clots have occurred between one and three weeks after people received the J&J vaccine, and officials cautioned that more reports could surface, the AP reported.

Booster shots a possibility

Vaccinated Americans will probably need booster shots to guard against emerging coronavirus variants in the future, a White House adviser and Pfizer’s CEO said Thursday.

The United States is already planning for future booster shots, Dr. David Kessler, chief science officer for the pandemic response, said during a House subcommittee hearing on the country’s vaccination efforts.

And in remarks released Thursday, Pfizer CEO Albert Bourla said the most likely scenario included the need for a third vaccine dose six to 12 months after initial inoculation, after which “there will be an annual revaccination.”

“There are vaccines like polio where one dose is enough, and there are vaccines like flu that you need every year,” Bourla said in a conversation hosted by CVS Health, CNBC News reported. “The COVID virus looks more like the influenza virus than the polio virus.”

In February, Pfizer said it was testing a third dose of its COVID-19 vaccine to understand the immune response against new variants of the virus. And Moderna said this week that it was at work on a booster for its vaccine, while Johnson & Johnson has said that its single-shot vaccine will probably need to be given annually, The New York Times reported.

Kessler, who runs the Biden administration’s vaccine effort, told the House subcommittee that the government was looking ahead, the Times reported. While he emphasized the “strong efficacy” of the current vaccines, including against the new variants, he said the government was “taking steps to develop [the] next generation of vaccines that are directed against these variants if in fact they can be more effective.”

He was one of several top health officials at the subcommittee hearing who implored Americans to get vaccinated and sought to reassure the country that all three federally authorized vaccines are safe. However, they said little about restarting distribution of J&J’s shots, which the U.S. Food and Drug Administration has paused to examine a handful of clotting cases in those who got the vaccine.

Late Thursday, the CDC said it had scheduled a new emergency hearing on the safety of J&J’s for April 23.

The U.S. coronavirus case count passed 31.6 million on Monday, while the death toll neared 567,000, according to a Times tally. Worldwide, more than 141.5 million cases had been reported by Monday, with over 3 million dead from COVID-19, according to data from Johns Hopkins University

More information

The U.S. Centers for Disease Control and Prevention has more on the new coronavirus.

SOURCES: The New York Times; Associated Press

Source: HealthDay