Post by Nadica (She/Her) on Nov 27, 2024 4:16:33 GMT
COVID-19 Vaccine Reactogenicity Among Young Children - Published Nov 25, 2024
Introduction
COVID-19 vaccine reactogenicity data among young children, which inform parental decisions and health care professional recommendations for vaccination, are limited. Reactogenicity can be described as expected and common symptoms after vaccination (eg, pain at injection site). We assessed reactions to COVID-19 vaccines among children of participants in the Centers for Disease Control and Prevention (CDC) COVID-19 Vaccine Pregnancy Registry (C19VPR).
Methods
From November 2022 to September 2023, C19VPR participants (people receiving a COVID-19 vaccine 30 days before last menstrual period or during pregnancy) who reported a live birth were asked at least 15 months after delivery about their child’s COVID-19 vaccination status. We asked participants to report local and systemic reactions, severity of reactions, reaction-related health care, and coadministration of other vaccines for each COVID-19 vaccine their child received; data were collected for up to 3 vaccinations. This activity was reviewed by the CDC and deemed public health surveillance, not research; it was exempt from Human Research Protections Office review and was conducted consistent with applicable federal law and CDC policy—for example, see, eg, 45 CFR part 46.102(l)(2), 21 CFR part 56; 42 USC §241(d); 5 USC §552a; 44 USC §3501 et seq. Details on C19VPR methodology are available1; additional analytic details are available in eMethods in Supplement 1. We excluded children without information on vaccine manufacturer and/or date. Participant race and ethnicity were self-reported and classified into smaller groups based on CDC methods for grouping race and ethnicity.2
We compared prevalence of adverse reactions by vaccine manufacturer, dose, and coadministration, using prevalence ratios adjusted for variables associated with reactions (ie, child age at dose 1 and history of childhood SARS-CoV-2 infection). Reactions across all doses were compared by manufacturer using binomial regression with generalized estimating equations to account for correlations introduced by including more than 1 dose for the same child. This study followed the STROBE reporting guideline. Analysis was conducted in SAS, version 9.4 (SAS Institute). Statistical tests were 2-sided with significance set as P < .05.
Results
Among 5644 children who received at least 1 dose of COVID-19 vaccine (2569 [45.5%] BNT162b2 [Pfizer-BioNTech]; 2972 [52.7%] mRNA-1273 [Moderna]), the mean age at first dose was 12.4 months (minimum, 6 months; maximum, 24 months) (Table; Figure). Coadministration of dose 1 with another vaccine was reported for 20.0% of children. Postvaccination reactions were reported for 46.7% of children, with 21.1% and 38.8% experiencing local and systemic reactions, respectively. Commonly reported reactions included irritability or fussiness (1700 [30.1%]), local reaction (1191 [21.1%]), and fever (779 [13.8%]). Among children with reported reactions, 18 of 56 (0.3%) experienced reactions described by participants as severe. In total, 87 of 5644 children (1.5%) were reported to have received care from a health care professional for a reaction after any dose (BNT162b2, 45 [1.8%]; mRNA-1273, 42 [1.4%]). Six participants reported a seizure or febrile seizure after receiving COVID-19 vaccination. No deaths were reported.
Among children receiving doses from the same manufacturer, a report of any reaction was significantly higher after dose 1 than dose 2 (BNT162b2, 39.1% vs 28.1%; mRNA-1273, 40.7% vs 33.1%). Any reaction was more common among children receiving only mRNA-1273 compared with only BNT162b2 (adjusted prevalence ratio, 1.14; 95% CI, 1.09-1.20) and with coadministration of another vaccine (adjusted prevalence ratio, 1.20; 95% CI, 1.13-1.29).
Discussion
No unexpected reactions were identified. Similar to our study, data from clinical trials and V-safe found that irritability was the most common systemic reaction among children aged 6 months to younger than 2 years, followed by fever and fatigue or sleepiness.3-7 In contrast to other studies observing a higher prevalence of reactions after the second COVID-19 vaccine dose, we observed a higher prevalence after the first dose. This difference may reflect maternal vaccination; the first COVID-19 vaccination in our cohort may be some children’s second immunological encounter with a COVID-19 vaccine. Generalizability may be limited because of a relatively demographically homogenous cohort, and participant-reported data may be subject to recall bias. These findings add evidence indicating that mild or moderate local and systemic reactions may be experienced, but severe reactions and serious adverse events are rare.
Introduction
COVID-19 vaccine reactogenicity data among young children, which inform parental decisions and health care professional recommendations for vaccination, are limited. Reactogenicity can be described as expected and common symptoms after vaccination (eg, pain at injection site). We assessed reactions to COVID-19 vaccines among children of participants in the Centers for Disease Control and Prevention (CDC) COVID-19 Vaccine Pregnancy Registry (C19VPR).
Methods
From November 2022 to September 2023, C19VPR participants (people receiving a COVID-19 vaccine 30 days before last menstrual period or during pregnancy) who reported a live birth were asked at least 15 months after delivery about their child’s COVID-19 vaccination status. We asked participants to report local and systemic reactions, severity of reactions, reaction-related health care, and coadministration of other vaccines for each COVID-19 vaccine their child received; data were collected for up to 3 vaccinations. This activity was reviewed by the CDC and deemed public health surveillance, not research; it was exempt from Human Research Protections Office review and was conducted consistent with applicable federal law and CDC policy—for example, see, eg, 45 CFR part 46.102(l)(2), 21 CFR part 56; 42 USC §241(d); 5 USC §552a; 44 USC §3501 et seq. Details on C19VPR methodology are available1; additional analytic details are available in eMethods in Supplement 1. We excluded children without information on vaccine manufacturer and/or date. Participant race and ethnicity were self-reported and classified into smaller groups based on CDC methods for grouping race and ethnicity.2
We compared prevalence of adverse reactions by vaccine manufacturer, dose, and coadministration, using prevalence ratios adjusted for variables associated with reactions (ie, child age at dose 1 and history of childhood SARS-CoV-2 infection). Reactions across all doses were compared by manufacturer using binomial regression with generalized estimating equations to account for correlations introduced by including more than 1 dose for the same child. This study followed the STROBE reporting guideline. Analysis was conducted in SAS, version 9.4 (SAS Institute). Statistical tests were 2-sided with significance set as P < .05.
Results
Among 5644 children who received at least 1 dose of COVID-19 vaccine (2569 [45.5%] BNT162b2 [Pfizer-BioNTech]; 2972 [52.7%] mRNA-1273 [Moderna]), the mean age at first dose was 12.4 months (minimum, 6 months; maximum, 24 months) (Table; Figure). Coadministration of dose 1 with another vaccine was reported for 20.0% of children. Postvaccination reactions were reported for 46.7% of children, with 21.1% and 38.8% experiencing local and systemic reactions, respectively. Commonly reported reactions included irritability or fussiness (1700 [30.1%]), local reaction (1191 [21.1%]), and fever (779 [13.8%]). Among children with reported reactions, 18 of 56 (0.3%) experienced reactions described by participants as severe. In total, 87 of 5644 children (1.5%) were reported to have received care from a health care professional for a reaction after any dose (BNT162b2, 45 [1.8%]; mRNA-1273, 42 [1.4%]). Six participants reported a seizure or febrile seizure after receiving COVID-19 vaccination. No deaths were reported.
Among children receiving doses from the same manufacturer, a report of any reaction was significantly higher after dose 1 than dose 2 (BNT162b2, 39.1% vs 28.1%; mRNA-1273, 40.7% vs 33.1%). Any reaction was more common among children receiving only mRNA-1273 compared with only BNT162b2 (adjusted prevalence ratio, 1.14; 95% CI, 1.09-1.20) and with coadministration of another vaccine (adjusted prevalence ratio, 1.20; 95% CI, 1.13-1.29).
Discussion
No unexpected reactions were identified. Similar to our study, data from clinical trials and V-safe found that irritability was the most common systemic reaction among children aged 6 months to younger than 2 years, followed by fever and fatigue or sleepiness.3-7 In contrast to other studies observing a higher prevalence of reactions after the second COVID-19 vaccine dose, we observed a higher prevalence after the first dose. This difference may reflect maternal vaccination; the first COVID-19 vaccination in our cohort may be some children’s second immunological encounter with a COVID-19 vaccine. Generalizability may be limited because of a relatively demographically homogenous cohort, and participant-reported data may be subject to recall bias. These findings add evidence indicating that mild or moderate local and systemic reactions may be experienced, but severe reactions and serious adverse events are rare.