Then came the Delta variant. Despite keeping their countries largely sealed off, the virus found its way in. And when it did, it spread quickly. In the summer, South Korea battled its worst wave of infections; hospitals in Indonesia ran out of oxygen and beds; and in Thailand, health care workers had to turn away patients.
With cases surging, countries quickly shifted their vaccination approach.
Sydney, Australia, announced a lockdown in June after an unvaccinated limousine driver caught the Delta variant from an American aircrew. Then, Prime Minister Scott Morrison, who had previously said vaccination “was not a race,” called in July on Australians to “go for gold” in the country’s inoculation drive.
The State of Vaccine Mandates in the U.S.
- Vaccine rules. On Aug. 23, the F.D.A. granted full approval to Pfizer-BioNTech’s coronavirus vaccine for people 16 and up, paving the way for mandates in both the public and private sectors. 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. California became the first state to issue a vaccine mandate for all educators in public and private schools. New York City has also introduced a vaccine mandate for teachers and staff, but it has yet to take effect because of legal challenges. On Sept. 27, a federal appeals panel reversed a decision that temporarily paused that mandate. it. Los Angeles has mandated vaccines for students 12 and older who are attending class in person.
- Hospitals and medical centers. Many hospitals and major health systems are requiring employees to get vaccinated. Mandates for health care workers in California and New York State appear to have compelled thousands of holdouts to receive shots.
- New York City. Proof of vaccination is required of workers and customers for indoor dining, gyms, performances and other indoor situations. City education staff and hospital workers must also get a vaccine.
- At the federal level. On Sept. 9, President Biden announced a vaccine mandate for the vast majority of federal workers. This mandate will apply to employees of the executive branch, including the White House and all federal agencies and members of the armed services.
- In the private sector. Mr. Biden has mandated that all companies with more than 100 workers require vaccination or weekly testing, helping propel new corporate vaccination policies. Some companies, like United Airlines and Tyson Foods, had mandates in place before Mr. Biden’s announcement.
He moved to overcome a supply shortage, compounded by the slow regulatory approval. In August, Australia bought one million Pfizer doses from Poland; this month, Mr. Morrison announced a purchase of a million Moderna shots from Europe.
When the Delta outbreak emerged, fewer than 25 percent of Australians over the age of 16 had received a single shot. In the state of New South Wales, which includes Sydney, 86 percent of the adult population has now received a first dose, and 62 percent of adults are fully vaccinated. The country expects to fully inoculate 80 percent of its population over the age of 16 by early November.
“There was great community leadership — there were people from across the political divide who came out to support vaccination,” said Greg Dore, an infectious-disease expert at the University of New South Wales. “It really helped us turn around a level of hesitancy that was there.”
Many governments have used incentives to encourage inoculations.
In South Korea, the authorities eased restrictions in August on private gatherings for fully vaccinated people, allowing them to meet in larger groups while maintaining stricter curbs for others. Singapore, which has fully vaccinated 82 percent of its population, previously announced similar measures.
Researchers there have also analyzed the pockets of people who refuse to be inoculated and are trying to persuade them.