The vaccines now in use are based on the form of the virus that circulated at the beginning of the pandemic and are less effective against the omicron variant. New options are in the works.
People who are 50 and older and certain immunocompromised individuals may get a second Pfizer-BioNTech or Moderna COVID-19 vaccine booster four months after they received the first.
The FDA now cautions against using a specific lot of Abbott Nutrition's Similac PM 60/40 after a second infant dies. Abbott voluntarily recalled the specialty product on Monday.
Abbott Nutrition voluntarily recalled some powdered formulas sold under the Similac, Alimentum and EleCare brands. The FDA is investigating links to four bacterial infections, one of which was fatal.
"We believe additional information regarding the ongoing evaluation of a third dose should be considered as part of our decision-making for potential authorization," FDA officials said in a statement.
The Food and Drug Administration this week approved an injectable drug that helps prevent the spread of HIV. It only has to be taken once every eight weeks, compared to a daily oral pill.
Omicron has many more mutations than previous variants of concern, a fact that raises questions about how effective existing vaccines will be against the new form of the coronavirus.
Officials say the recall was prompted after a random sample tested positive for the organism listeria monocytogenes. No illnesses have been reported, the FDA says.
The Food and Drug Administration also gave an OK to boosters that differ from the vaccine originally used to immunize people against COVID-19. A mix-and-match approach could ease the booster rollout.