The Food and Drug Administration has granted authorization for the updated COVID-19 booster shots for children between the ages of six months and five.

The updated bivalent vaccine provides protection against the BA.4 and BA.5 subvariants of the omicron strain of COVID-19.

The authorization applies to booster shots manufactured by Pfizer and Moderna, though eligibility rules are different for each brand.

Children who received the original Moderna vaccine can receive a single booster two months after completing the primary series.

Children who have not started the three-dose primary series of Pfizer's vaccine or who have not received the third dose of their primary series will receive the updated booster shot.

Children who have already completed their three-dose primary series with Pfizer's original vaccine are not eligible for a booster dose of the updated bivalent vaccine at this time.

"Vaccines remain the best defense against the most devastating consequences of disease caused by the currently circulating omicron variant, such as hospitalization and death. Based on available data, the updated, bivalent vaccines are expected to provide increased protection against COVID-19," said Peter Marks, M.D., Ph.D., director of the FDA's Center for Biologics Evaluation and Research. "Parents and caregivers can be assured that the FDA has taken a great deal of care in our review, and we encourage parents of children of any age who are eligible for primary vaccination or a bivalent COVID-19 vaccine booster dose to consider seeking vaccination now as it can potentially help protect them from COVID-19 during a time when cases are increasing."