As of the end of September 2022, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, which causes Coronavirus Disease 2019, had been detected in nearly 15 million children in the US (COVID-19).
Presently, children make up about 18.5% of COVID-19 cases that have been reported in the US. Children and infants who contract SARS-CoV-2 may develop severe illnesses and require hospitalization. Children under six months old made up 44% of hospitalizations among children ages 0 to 4 years old during the Omicron predominance.
The best defense against COVID-19 and its complications is vaccination. In clinical trials and the real world, COVID-19 vaccines have shown to be highly effective, particularly against the original and Delta variants of the virus. Data from the real world indicate decreased COVID-19 vaccine protection against Omicron variants. However, infants younger than six months old are not eligible for any COVID-19 vaccines currently on the market and must rely on maternal placentally acquired immunity.
Between December 15, 2020, and May 31, 2022, we located 62,117 infants born at Kaiser Permanente Northern California (KPNC), an integrated healthcare delivery system. For our primary analysis, we excluded 10,412 (16.8%) infants and 21,891 (35.2%) based on the maternal exclusion criteria.
19 418 (64.06%) of the cohort’s mothers were unvaccinated while pregnant, 1138 (3.75%) had only received one dose of the mRNA COVID-19 vaccine, and 9755 (32.18%) had received two doses. The vaccine was given to most mothers (1032 out of 1138) who only received one dose during the third trimester.
Only 32% of the babies in the cohort in the current study’s mothers received at least two doses during pregnancy. Even though this percentage may not be representative of the rate of immunized pregnant women within KPNC due to our exclusion criteria, more efforts are needed to promote COVID-19 vaccines for pregnant people because vaccination protects mothers and their infants until they are old enough to receive their COVID-19 vaccine.