The US health regulator on 23 August gave full approval to Pfizer-BioNTech's COVID-19 vaccine, a key milestone for public health that can instil further confidence in consumers and also spur authorities to make vaccinations mandatory.

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The US Food and Drug Administration (USFDA) had earlier in December 2020 given emergency use authorisation (EAU) for the vaccine, developed by US-based Pfizer and its German partner BioNTech. More than 200 million Pfizer doses have been administered in the US, and hundreds of millions more worldwide, since December. "Today the US Food and Drug Administration approved the first COVID-19 vaccine. The vaccine has been known as the Pfizer-BioNTech COVID-19 Vaccine, and will now be marketed as Comirnaty, for the prevention of COVID-19 disease in individuals 16 years of age and older," the US health regulator said in a statement.

The vaccine also continues to be available under emergency use authorisation, including for individuals 12 through 15 years of age and for the administration of the third dose in certain immunocompromised individuals, it added. "The FDA's approval of this vaccine is a milestone as we continue to battle the COVID-19 pandemic," Acting FDA Commissioner Janet Woodcock said.

While this and other vaccines have met the FDA's rigorous, scientific standards for emergency use authorisation, as the first FDA-approved COVID-19 vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product, she added. "While millions of people have already safely received COVID-19 vaccines, we recognise that for some, the FDA approval of a vaccine may now instil additional confidence to get vaccinated. Today's milestone puts us one step closer to altering the course of this pandemic in the US," Woodcock said.

Pfizer CEO Albert Bourla said in a statement he hopes the decision "will help increase confidence in our vaccine, as vaccination remains the best tool we have to help protect lives." Comirnaty contains messenger RNA (mRNA), a kind of genetic material. "To support the FDA's approval decision today, the FDA reviewed updated data from the clinical trial which supported the EUA and included a longer duration of follow-up in a larger clinical trial population," the FDA said.

Specifically, in the FDA's review for approval, the agency analysed effectiveness data from approximately 20,000 vaccine and 20,000 placebo recipients ages 16 and older who did not have evidence of the COVID-19 virus infection within a week of receiving the second dose. The safety of Pfizer-BioNTech COVID-19 vaccine was evaluated in approximately 22,000 people who received the vaccine and 22,000 people who received a placebo 16 years of age and older, it added.

"Based on results from the clinical trial, the vaccine was 91% effective in preventing COVID-19 disease," FDA said. More than half of the clinical trial participants were followed for safety outcomes for at least four months after the second dose. Overall, approximately 12,000 recipients have been followed for at least 6 months, it added. The vaccine is effective in preventing COVID-19 and potentially serious outcomes including hospitalisation and death, the US health regulator said.

US vaccinations bottomed out in July at an average of about a half-million shots per day, down from a peak of 3.4 million a day in mid-April. With Delta variant cases on the rise, the pace of vaccination has increased, with a million jabs a day given on Thursday, Friday and Saturday. Just over half of the US population is fully vaccinated with one of the country's three options -- Pfizer, Moderna or Johnson & Johnson. Moderna has also applied to the FDA for full approval of its vaccine. J&J said it hopes to do so later this year.

The FDA already is allowing the emergency use of the third dose of either the Pfizer or Moderna vaccine for people with severely weakened immune systems. For everyone else who got those vaccinations, the Biden administration is planning for boosters starting in the fall, if the FDA and the Centers for Disease Control and Prevention agree. This month, New York City, New Orleans and San Francisco all imposed proof-of-vaccination requirements at restaurants, bars and other indoor venues.

At the federal level, President Joe Biden is requiring government workers to sign forms attesting that they have been vaccinated or else submit to regular testing and other requirements. Anxious Americans increasingly are on board -- close to 6 in 10 favour requiring people to be fully vaccinated to travel on aeroplanes or attend crowded public events, according to a recent poll by The Associated Press-NORC Center for Public Affairs Research. The Delta variant has sent cases, deaths and hospitalisations soaring in recent weeks in the US, erasing months of progress.