AdvertisementModerna asks FDA to authorize first COVID-19 vaccine for very young children04:14Download AudioResumeApril 28, 2022Rob SteinfacebookEmailModerna says its vaccine appears to be about 51 percent effective for children ages 6 months to less than 2 years, and 37 percent effective for those ages 2 to less than 6 years. (dpa picture alliance via Getty Images)