The weekly report from the Centers for Disease Control and Prevention (CDC), revealed the response to vaccines - local and systemic reactions, in children aged 5-11 years after Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccination in the United States.
After the authorization and administration of approximately 8.7 million vaccine doses in children during November 3–December 19, 2021, serious adverse events were rarely reported as per the information collected in surveillance systems.
Based on the observations, the authors advised the parents and guardians of the children to expect local and systemic reactions after vaccination with the Pfizer-BioNTech COVID-19 vaccine. These reactions are more common after the second dose.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of COVID-19. It is an illness that may cause fever, cough, fatigue, breathing difficulties, or even death. To date, SARS-CoV-2 has infected over 281 million individuals and has caused over 5.4 million deaths globally.
The vaccines, developed in an unprecedented history of medicine and biotechnology, were first administered to the first responders and frontline health workers, the elderly, and those suffering co-morbidities.
Currently, over 8.687 billion vaccine doses have been administered to adults globally. While the approval for administering vaccines has been extended to include lower age groups (12-17 years), the authorization for children is yet to be validated.
The preauthorization clinical trials for the Pfizer-BioNTech COVID-19 vaccine included 3,109 children aged 5–11 years; the researchers observed most adverse events to be mild to moderate, with no serious adverse events related to vaccination.
To further characterize the safety of the vaccine in young children, the CDC reviewed the adverse events as reported to the Vaccine Adverse Event Reporting System (VAERS), and v-safe.
VAERS is a ‘passive vaccine safety surveillance system that is co-managed by the CDC and Food and Drug Administration (FDA).’ The VAERS reports are classified as serious if any of the following are reported: hospitalization, prolongation of hospitalization, life-threatening illness, permanent disability, congenital anomaly or birth defect, or death. The serious events are followed up by CDC physicians and reviewed in detail.
V-safe is a voluntary smartphone-based safety tool as a surveillance system for adverse health events after COVID-19 vaccination. It is established by CDC specifically to monitor any adverse events post-COVID-19-vaccination. The health surveys included detailed questions about local injection sites and systemic reactions and health impacts (i.e., whether the child was unable to perform normal daily activities, missed school, or received care from a medical professional because of new symptoms or conditions).
The safety reports and findings
Of the approximately 8.7 million doses of Pfizer-BioNTech COVID-19 vaccines administered to children aged 5–11 years during the period, VAERS received 4,249 reports of adverse events after vaccination. About 97.6% of these reports were non-serious.
In the v-safe reports, 42,504 children aged 5–11 years were enrolled. After the second dose of the Pfizer-BioNTech COVID-19 vaccine, 57.5% local and 40.9% systemic reactions (including injection-site pain, fatigue, or headache) were noted.
The collected data are presented according to the adverse event reports by selected demographic characteristics and reported symptoms. The authors also tabulated the list of the most frequent symptoms, signs, diagnostic results, and conditions by Medical Dictionary for Regulatory Activities (MedDRA) preferred term.
The most common adverse event reported is an administrative error. The children in this age group (5-11 years old) were the first to receive a smaller dosage of the mRNA vaccine (10 μg) than that recommended for persons aged over 12 years (30 μg). However, despite the error in administrating an incorrect dose, no adverse events are associated with this event.
The most commonly reported conditions among the children are fever, vomiting, and increased troponin (proteins found in the heart muscle cells, measured to evaluate chest pain or myocardial damage).
Myocarditis, a rare and serious adverse event, has been associated with mRNA-based COVID-19 vaccines specifically more among males aged 12–29 years. In this report among children aged 5-11 years, the data on myocarditis appears rare. Eleven reports were received after the administration of approximately eight million vaccine doses; all of them are recovered or under-recovery.
Even though two deaths for children with multiple chronic medical conditions after the Pfizer-BioNTech COVID-19 vaccine were reported, there is no causal association between death and vaccination. It is reported that both the children were in fragile health before vaccination.
Interestingly, the local and systemic reactions observed among children aged 5–11 years were less than reactions reported among children and adolescents aged 12–15 years. This report is as per the v-safe registrants.
Fourteen of the v-safe registrants reported being hospitalized after vaccination; however, whether hospitalization was the direct result of vaccination could not be determined.
Importantly, the preliminary safety findings were similar to the observations from the preauthorization clinical trials. Therefore, the Advisory Committee on Immunization Practices (ACIP) recommended that the Pfizer-BioNTech COVID-19 vaccine may be administered to children aged 5–11 years for the prevention of COVID-19.
This VAER report is a passive surveillance reporting system. Therefore, it is highly subjective to biases and underreporting. The data here does not cover race and ethnicity in all the cases. The V-safe is completely dependent on voluntary reporting and hence may not truly reflect the vaccinated population. Finally, the authors warn that these data are limited by the short surveillance period and thus, are subject to changes with time and more doses.
The report notes menial or nil severe adverse events and therefore recommends COVID-19 vaccination among children aged 5-11 years old. Further, it advises parents and guardians of these children vaccinated with the Pfizer-BioNTech COVID-19 vaccine to expect local and systemic reactions post-vaccination. Vaccination is the most effective way to prevent COVID-19, the report concludes.
However, for the general benefit, it is to be noted that this study reports only on the small percentage of data collected in the surveillance systems and is not inclusive of all the 8.7 million vaccinations administered to young children.