Editor's note: Because information on COVID-19 continues to evolve, this content may have changed since we went to press in mid-October.

* On August 5, vaccine maker Novavax announced it had asked regulators in India, Indonesia, and the Philippines to allow emergency use of its COVID-19 vaccine, offering it first to low-income countries before wealthier ones with ample supplies.

* On August 23, the Food and Drug Administration (FDA) granted full approval to Pfizer's COVID-19 vaccine (marketed as Comirnaty) in people ages 16 and older. The vaccine is still available for those ages 12 to 15 under emergency use authorization.

* People who know they were infected with SARS-CoV-2 in the past may need only one dose of the Pfizer vaccine to gain strong immunity, according to a small study published in the August 6 JAMA Network Open. The study highlighted, however, that prior infection alone was not a robust defense against COVID-19.

* On September 9, President Biden announced that private sector businesses with 100 or more employees must require COVID-19 vaccination or weekly testing for their workers. Approximately 17 million health care workers employed by hospitals and other institutions that accept Medicare and Medicaid reimbursement will also face strict new vaccination requirements, as will federal workers and contractors. Several states, such as California and New York, have also mandated vaccines for health care workers.

* On September 17, the FDA's Vaccines and Related Biological Products Advisory Committee voted unanimously to recommend an additional booster dose of COVID-19 vaccine for people ages 65 and older and for those at risk for severe illness, including health care workers and those at high risk for occupational exposure.