The Biden administration may scrap plans to expand eligibility for second boosters to younger adults. Instead, it's trying to speed up the next generation of boosters targeting the omicron variant.
Pfizer and BioNTech, which produced the first COVID-19 vaccine authorized in the U.S., say they will expand ongoing trials to include a third dose for children as young as 6 months old.
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.
The companies studied a 10 microgram vaccine dose in children 5 to 11, a third of the dose used for adults, to minimize side effects and because it still prompts a strong immune response.
Pfizer and BioNTech say that early trial results show their vaccine established a strong antibody response against the coronavirus. FDA review is still needed.
As of late May, 50.6% of Canada's population had received at least one vaccination shot — but only 4.6% of the population was fully vaccinated.
The FDA has authorized storing the Pfizer-BioNTech COVID-19 vaccine at refrigerator temperatures for up to a month. Previously the vaccine could only be kept in a regular fridge for up to 5 days.
Pfizer said in late March that clinical trials found "100% efficacy and robust antibody responses" to the coronavirus in 12- to 15-year-olds.
With the Tokyo Games weeks away, the pharmaceutical company and its German partner, BioNTech, have agreed to donate the necessary doses.
Agency officials said reducing the number of doses creates a potential for harm in patients because "they may assume that they are fully protected when they are not" and may "take unnecessary risks."