The agency announced on Tuesday that any kid in that age group who finished their primary vaccination series at least five months ago can go ahead and get their booster. Pfizer-BioNTech’s mRNA-based vaccine is currently the only COVID-19 immunization and booster available for children ages 5 through 17. Children younger than 5 are the only US age group that remains ineligible for a COVID shot. “Vaccination continues to be the most effective way to prevent COVID-19 and its severe consequences, and it is safe,” FDA Commissioner Robert M. Califf said in a statement. “If your child is eligible for the Pfizer-BioNTech COVID-19 vaccine and has not yet received their primary series, getting them vaccinated can help protect them from the potentially severe consequences that can occur, such as hospitalization and death.”    It’s unclear whether this new announcement will spur many parents to take their kids for COVID shots. Vaccination rates for children continue to lag far behind those of older populations. Although the FDA authorized the Pfizer-BioNTech vaccine for use in children ages 5 through 11 in November, the Centers for Disease Control and Prevention report that just 29 percent of those children are fully vaccinated.  While the FDA has authorized Pfizer-BioNTech’s booster for this new age cohort, the CDC still has to decide whether it wants to formally recommend the booster for these kids. The agency will discuss this option when it meets with its panel of expert advisers on Thursday. Adults aged 18 and older in the US are eligible for primary vaccines and boosters made by Pfizer-BioNTech, Moderna, or Johnson & Johnson. People ages 50 and older are also eligible for a second booster, though the guidance for those boosters on the Centers for Disease Control and Prevention’s website was quietly updated Friday, indicating those who are eligible may want to wait till the fall to get additional shots in case variant-specific vaccines become available. Another group must continue to wait, too: Parents of the country’s youngest children. The expected timelines for vaccine approval for children under 5 have been repeatedly pushed back. Both Pfizer and Moderna have been studying their vaccines’ effectiveness in small children, and the FDA is set to review those data in June. According to the CDC, 491 kids under the age of 5 have died from COVID-19. Evidence shows that children are also vulnerable to long COVID. However, research suggests that as many as three-quarters of all US children have already been infected by coronavirus, specifically during the winter Omicron wave.