On Dec. 5, Pfizer applied for the FDA's emergency use authorization on its updated COVID-19 booster for children between 6 months and 4 years old.
Like the company's omicron-focused boosters that were authorized a few months ago, these vaccine candidates are engineered to target omicron subvariants BA.4 and BA.5. As of Dec. 3, BA.5 accounts for 13.8 percent and BA.4 makes up 0 percent of COVID-19 infections. In mid-November, omicron subvariants BQ.1 and BQ.1.1 surpassed the "sister variants" in prevalence.
Currently, Pfizer's tweaked vaccine is authorized for emergency use in those who are 5 years and older.