Novavax submits final data to FDA for emergency use authorization of its Covid-19 vaccine, the United States orders another 10 million doses of Pfizer's Covid-19 antiviral pill, and more in this week's roundup of Covid-19 news.

• Covid-19 vaccines do not increase the risk of preterm or small-for-gestational-age births in pregnant people, according to a new study published Tuesday in CDC's Morbidity and Mortality Weekly Report. For the study, researchers examined 46,079 singleton pregnancies, including 10,064 among individuals who received at least one dose of a Covid-19 vaccine between Dec. 15, 2020, and July 22, 2021. Of the individuals who were vaccinated, most received the Pfizer-BioNTech or Moderna vaccines. Overall, the researchers found that 6.6% of all the infants had been born prematurely and 8.2% were born small for their gestational age. There were no differences in rates among individuals who had been vaccinated and those who had not. The researchers said their findings "[support] the safety of Covid-19 vaccination during pregnancy." According to the New York Times, the researchers plan to conduct follow-up studies to find out if Covid-19 affects infants and their development. (Rabin, New York Times, 1/4; AHA News, 1/4; D'Ambrosio, MedPage Today, 1/4; Coleman, The Hill, 1/4)

• President Joe Biden on Tuesday announced the United States will purchase 20 million courses of Pfizer's Covid-19 antiviral pill, Paxlovid—doubling a previous order of 10 million. The drug, along with a similar Covid-19 pill developed by Merck, was authorized for emergency use by FDA late last month. According to Pfizer, the delivery of the first 10 million courses will be complete by June, and the second 10 million will be ready by September. Previously, the White House said that around 265,000 courses will be available in January, The Hill reports. In addition, some experts have criticized the current limited supply of Paxlovid, particularly as Covid-19 cases continue to surge around the country. "It's still way too small and too late to meet the anticipated needs," said Eric Topol, a professor of molecular medicine at Scripps Research. (Sullivan, The Hill, 1/4; Saric, Axios, 1/4)

• CDC on Tuesday updated its Covid-19 vaccine guidance to recommend individuals who initially received Pfizer-BioNTech's vaccine get a booster dose after five months instead of six. The move comes after FDA on Monday authorized reducing the booster interval for Pfizer-BioNTech's vaccine to five months, saying that a third shot at that time may "provide better protection sooner for individuals against the highly transmissible omicron variant." According to Axios, CDC's booster recommendations for the Moderna and Johnson & Johnson vaccines remain the same at six and two months, respectively. In addition to shortening the booster interval for Pfizer-BioNTech recipients, CDC also recommended that children ages 5-11 who are immunocompromised receive an additional vaccine dose 28 days after their second shot. "[The new] recommendations ensure people are able to get a boost of protection in the face of omicron and increasing cases across the country, and ensure that the most vulnerable children can get an additional dose to optimize protection against Covid-19," said CDC Director Rochelle Walensky. (Gonzalez, Axios, 1/4; Coleman, The Hill, 1/4; Sullivan, NPR, 1/4)

• Novavax last week filed final data for its protein-based Covid-19 vaccine with FDA, potentially clearing the way for an emergency use authorization early this year, The Hill reports. A phase 3 trial in the United States and Mexico with more than 25,000 participants found that the vaccine had an efficacy rate of 90%. "Novavax is committed to delivering our protein-based vaccine in the United States, where the Covid-19 pandemic continues to evolve with the emergence of new variants," said Stanley Erck, the company's president and CEO. Last month, the European Commission authorized Novavax's Covid-19 vaccine for use in the European Union. (Dress, The Hill, 12/31/21)

• FDA last week authorized an at-home Covid-19 test manufactured by Siemens Healthineers, adding to the United States' testing supply as demand surges, The Hill reports. The test can be self-administered by those ages 14 and older, or parents can use it to test their children ages 2 to 13. According to Axios, Siemens Healthineers' test is expected to be available to the public starting in January. "Increasing Americans' access to easy-to-use, reliable Covid tests is a top priority for the Biden administration, and we are using all resources at our disposal to make more tests available and ramp up supply," said HHS Secretary Xavier Becerra. "Adding two new authorized tests will give Americans more options for testing at home, which helps keep people safe and provides peace of mind." Previously, the Biden administration committed to purchasing 500 million at-home Covid-19 tests that will be distributed to Americans free of charge. (Falconer, Axios, 12/30/21; Choi, The Hill, 12/29/21)

• COVAX, an initiative aiming to distribute Covid-19 vaccines around the world, shipped more than 900 million vaccine doses to 144 countries in 2021, The Hill reports, with a record 309 million of those doses shipped in December. However, COVAX fell over a billion doses short of the 2 billion goal it had set for itself in 2021. During a media conference, World Health Organization Director-General Tedros Adhanom Ghebreyesus said he was optimistic about COVAX's work going into the new year. "Our projections show that supply should be sufficient to vaccinate the entire global population, and to give boosters to high-risk populations by the first quarter of 2022," he said. In addition, Tedros underscored the need to curtail vaccine inequity to end the pandemic. "The longer inequity continues, the higher the risks of the virus evolving in ways we can't prevent or predict," he said. "If we end inequity, we end the pandemic. In turn, we save lives, we relieve the burden on health systems and give respite to the legions of health workers who have toiled tirelessly and sacrificed so much for two years." (Dress, The Hill, 1/1; Aizenman, "Goats and Soda," NPR, 12/30/21; Dress, The Hill, 12/31/21)