Abstract and Introduction
Approximately 12 million children and adolescents aged ≤18 years in the United States have been infected with SARS-CoV-2, the virus that causes COVID-19, since December 2019,* and COVID-19–associated hospitalization rates increased among children aged <5 years during the B.1.617.2 (Delta) and B.1.1.529 (Omicron) variant peaks. In June 2022, the Food and Drug Administration amended the Emergency Use Authorization for the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine to include use of the vaccine in children aged 6 months–4 years and mRNA-1273 (Moderna) for children 6 months–5 years, which CDC recommends all children receive.† Advance reports indicated that fewer than 50% of parents were willing to vaccinate their children aged <5 years.[2,3] Using the Pediatric Research Observing Trends and Exposures in COVID-19 Timelines (PROTECT)§  prospective cohort, changes in parental perceptions toward COVID-19 vaccines and vaccination¶ for children aged <5 years were examined during July 2021–May 2022. Among 393 parents who participated in a baseline survey, approximately 64%, 19%, and 10% reported they were likely, were unsure, or were unlikely, respectively, to have their child aged <5 years receive the COVID-19 vaccine. The odds of parents intending to vaccinate their child was lower 3 months after the baseline survey, (adjusted odds ratio [aOR] = 0.84, 95% CI = 0.6–1.0) than at baseline. During the same period, parents also were less likely to perceive that COVID-19 vaccines were effective (aOR = 0.61, 95% CI = 0.4–0.8) and safe (aOR = 0.65, 95% CI = 0.5–0.9) compared with baseline. Intent to vaccinate and perception of safety increased 6 months after the baseline survey in unadjusted models (OR = 1.66, 95% CI = 1.1–2.5; and OR = 1.82, 95% CI = 1.3–2.6, respectively), but were no longer significant after adjusting for the child's receipt of a positive SARS-CoV-2 test result before survey completion, age, sex, race and ethnicity, health insurance, and study site. Enhanced efforts to address parental confidence in childhood vaccination and increase vaccination coverage among children aged <5 years are needed, including reinforcing the effectiveness and safety of vaccination against COVID-19.
PROTECT is an ongoing prospective cohort that includes >2,300 children and adolescents aged 4 months–17 years; the study monitors infections with SARS-CoV-2 in Arizona, Florida, Texas, and Utah. Children were recruited via community outreach from the public and from families participating in the HEROES-RECOVER longitudinal cohorts of essential and frontline workers.[5,6] Upon enrollment, parents provided sociodemographic information, COVID-19 illness history, vaccination history, and their perceptions about COVID-19 vaccines for children. Participants are surveyed every 3 months. SARS-CoV-2 infections are identified among participant children through midturbinate nasal specimens collected weekly and tested via reverse transcription–polymerase chain reaction. Parents who completed the baseline survey and at least one follow-up survey were included in analysis. One child was randomly selected from households with two or more children aged <5 years to avoid household clustering. This study was restricted to 393 children aged <5 years who were enrolled in the PROTECT study during July 2021–May 2022. Vaccine intention was ascertained using baseline parental responses to the question, "What are the chances that [child] will get a COVID-19 vaccination?" Responses were grouped into three categories: unlikely (almost zero chance, very small chance); unsure (small chance, do not know, moderate chance); and likely (large chance, very large chance, almost certain).
A generalized estimating equation (GEE) model was used for each question to evaluate whether within-parent responses changed from a neutral or negative response (unsure or unlikely) to a positive response 3 and 6 months after the baseline enrollment survey. All available surveys from participants in the analytic group were included in the GEE models. The survey time point was added as a categorical predictor to calculate the OR for vaccine intention and vaccine perceptions. In addition, ORs describe the likelihood of all participants providing more positive responses at the 3-month and 6-month surveys compared with the baseline survey. Both unadjusted and adjusted models were calculated; the adjusted model included a positive test for SARS-CoV-2 infection in the child between surveys, sociodemographic characteristics, and study site. For vaccination intention outcomes, GEE models with multinomial distributions and cumulative logit links were used; the other models assessing perception outcomes used binomial distributions and logit links. All statistical analyses were completed using SAS (version 9.4; SAS Institute); statistical significance was defined as p<0.05 for chi-square tests and nonoverlapping 95% CIs for GEE models. PROTECT was reviewed by CDC and approved by the Institutional Review Boards at University of Arizona and Abt Associates under reliance agreements; the study was conducted consistent with applicable federal law and CDC policy.**
During July 2021–May 2022, parents provided information on 393 children aged <5 years enrolled in the PROTECT study (Table 1). The majority of children (227; 58%) resided in Arizona, and 92 (23%) had parents in the HEROES-RECOVER cohort.[5,6] Median age was 2.8 years (SD = 1.3 year); 189 (48%) were male, 183 (47%) were non-Hispanic White persons, and 110 (28%) were Hispanic persons; 132 (34%) children received a positive SARS-CoV-2 test result during the study. At baseline, 253 (64.4%) parents reported that they were likely to get their child vaccinated; 76 (19.3%) were unsure, and 39 (9.9%) reported that they were unlikely to vaccinate their child (Table 1). There were statistically significant differences in vaccine intention identified by study site (p<0.001), positive SARS-CoV-2 test result during the study (p = 0.006), percent of household members vaccinated (p = 0.011), and household income (p = 0.003).
Approximately two thirds of participants (270; 68.7%) completed a 3-month survey and 137 (34.9%) completed a 6-month survey (Table 2) (Figure). Among parents who completed a 3-month survey, 11 (4.1%) changed their vaccination intent from a neutral or negative to positive response after 3 months, although parents overall were 24% less likely to vaccinate (aOR = 0.76) than they were at baseline. Also at 3 months, 30 (11.2%) parents changed their perception of vaccine effectiveness from neutral or negative to positive, although overall, they were 39% less likely to perceive the vaccine as effective (aOR = 0.61). At 3 months after the baseline survey, perception of vaccine safety changed from neutral or negative to positive for 29 (10.9%) parents; however, overall parents were 35% less likely to perceive the vaccine as safe (aOR = 0.65). When asked about perceived trust in government, 28 (10.7%) of parents changed from a negative or neutral to a positive response after 3 months, although they were 51% less likely to report trust in the government compared with baseline (aOR = 0.49).
Distribution of 3-month and 6-month surveys, by study month — Pediatric Research Observing Trends and Exposures in COVID-19 Timelines cohort, four states, October 2021–May 2022
Among 137 parents who completed a 6-month survey, 11 (8.1%) changed their perception of vaccine effectiveness from neutral or negative to positive (Table 2); overall parents were 62% less likely to have a positive response (aOR = 0.38) regarding vaccine effectiveness. Eleven (8.4%) parents changed their level of trust in government from negative or neutral to positive, although overall, parents were 49% less likely to have a positive response (aOR = 0.51). In unadjusted models only, vaccination intent and perceptions of vaccine safety were less likely to be neutral or negative at 6 months (OR = 1.66 and OR = 1.82, respectively); after adjusting for receipt of a positive SARS-CoV-2 test result before 6-month survey completion, age, sex, race and ethnicity, health insurance, and site, these were no longer statistically significant.
Morbidity and Mortality Weekly Report. 2022;71(35):1109-1114. © 2022 Centers for Disease Control and Prevention (CDC)