As the Delta variant rages around the world, a heated debate has arisen over whether public health officials should recommend booster shots.
On one side are global health officials who contend that available vaccines would be better used to inoculate high-risk people in poor nations where few have gotten the shots.
On the other are leaders and health officials in wealthier countries, who are setting aside doses for more vulnerable people who may need additional doses to protect them from the virus.
Biden administration officials have already begun developing a plan that would roll out third shots of the Pfizer and Moderna vaccines as early as this fall, saying the logistics are too complicated to wait for scientific certainty that the extra doses are really needed.
Full vaccination is highly effective at protecting against severe disease caused by the virus, and it is not yet clear how soon additional doses might be necessary for certain groups. Some vaccines require boosters to remain highly protective.
In the United States, federal officials last week authorized a third shot of the Pfizer and Moderna vaccines for people with compromised immune systems because of organ transplants, chemotherapy or other medical conditions.
But officials at the Food and Drug Administration and the Centers for Disease Control and Prevention have said that authorizing third doses for immunocompromised people was a separate issue from whether booster doses were needed for the rest of the population.
Pfizer has pushed for swift authorization of third doses, but U.S. officials said in July that they would need more data, possibly months’ worth, before they could answer the question.
Some individuals are taking matters into their own hands. Just over a million people who received a two-dose vaccine in the United States have already received a third dose, Dr. Kathleen Dooling, a C.D.C. official, said on Friday. It was not clear how many were immunosuppressed.
Understand the State of Vaccine and Mask Mandates in the U.S.
- Mask rules. The Centers for Disease Control and Prevention in July recommended that all Americans, regardless of vaccination status, wear masks in indoor public places within areas experiencing outbreaks, a reversal of the guidance it offered in May. See where the C.D.C. guidance would apply, and where states have instituted their own mask policies. The battle over masks has become contentious in some states, with some local leaders defying state bans.
- Vaccine rules . . . and businesses. Private companies are increasingly mandating coronavirus vaccines for employees, with varying approaches. Such mandates are legally allowed and have been upheld in court challenges.
- College and universities. More than 400 colleges and universities are requiring students to be vaccinated against Covid-19. Almost all are in states that voted for President Biden.
- Schools. On Aug. 11, California announced that it would require teachers and staff of both public and private schools to be vaccinated or face regular testing, the first state in the nation to do so. A survey released in August found that many American parents of school-age children are opposed to mandated vaccines for students, but were more supportive of mask mandates for students, teachers and staff members who do not have their shots.
- Hospitals and medical centers. Many hospitals and major health systems are requiring employees to get a Covid-19 vaccine, citing rising caseloads fueled by the Delta variant and stubbornly low vaccination rates in their communities, even within their work force.
- New York. On Aug. 3, Mayor Bill de Blasio of New York announced that proof of vaccination would be required of workers and customers for indoor dining, gyms, performances and other indoor situations, becoming the first U.S. city to require vaccines for a broad range of activities. City hospital workers must also get a vaccine or be subjected to weekly testing. Similar rules are in place for New York State employees.
- At the federal level. The Pentagon announced that it would seek to make coronavirus vaccinations mandatory for the country’s 1.3 million active-duty troops “no later” than the middle of September. President Biden announced that all civilian federal employees would have to be vaccinated against the coronavirus or submit to regular testing, social distancing, mask requirements and restrictions on most travel.
Officials from the World Health Organization argue fiercely that booster programs will further deprive lower-income countries of desperately needed vaccines.
Leaving large swaths of the world unvaccinated, W.H.O. officials say, is wasteful, shortsighted and gives the virus enormous latitude to mutate into potentially more transmissible or virulent variants.
International vaccine distribution has been wildly unequal. Many countries in North America and Europe have at least partially vaccinated more than half of their populations, compared with barely more than 4 percent of Africa’s population, according to the Our World in Data project at Oxford University.
At a briefing this month, the W.H.O.’s director general, Dr. Tedros Adhanom Ghebreyesus, called for richer countries to stop giving third doses until the end of September. “We cannot — and we should not — accept countries that have already used most of the global supply of vaccines using even more of it, while the world’s most vulnerable people remain unprotected,” he said.
In an essay in the British newspaper The Guardian on Friday, Andrew Pollard, the director of the Oxford Vaccine Group at the University of Oxford, and Seth Berkley, the chief executive of Gavi, a global vaccine alliance, said that there was not enough evidence yet to enable a decision on boosters.
“Large-scale boosting in one rich country would send a signal around the world that boosters are needed everywhere,” they wrote. “This will suck many vaccine doses out of the system, and many more people will die because they never even had a chance to get a single dose.”