"This study provides us with important data showing the protective effects of the vaccine against long-haul COVID and suggests that this protection is mostly from preventing visible infections."
Vaccination against SARS-CoV-2 was associated with reduced risk of long COVID for at least 12 months in children and adolescents in a new large retrospective study.
Vaccination against SARS-CoV-2 provides moderate protection against long COVID in children and adolescents, with a stronger effect in adolescents aged 12-17 years, according to new research published in the journal Pediatrics.1
Vaccination has been shown to reduce the risk of acute COVID-19 in children and adolescents, however, it is less clear whether COVID-19 vaccines protect against long COVID, according to authors of the large retrospective study of over 1 million children in the US.1
“To date, no studies have assessed clinical data for large, diverse groups of children to address this important question,” said lead author Hanieh Razzaghi, PhD, MPH, a data scientist at The Children’s Hospital of Philadelphia, in a press release. “Using clinical data from across health care networks allowed us to have a large enough sample of patients to identify rare effects of the virus and its impact on children.”2
"This study provides us with important data showing the protective effects of the vaccine against long-haul COVID and suggests that this protection is mostly from preventing visible infections."
Razzaghi and colleagues analyzed electronic health record data from 17 health systems in the RECOVER PCORnet program to assess vaccine effectiveness against long COVID in 2 groups of patients—aged 5-11 years and 12-17 years—as well as the time period in which patients were impacted. They adjusted for sex, ethnicity, health system, comorbidity burden, and pre-exposure health care utilization, according to the study. They examined diagnosed long COVID as well as probable, or symptom-based long COVID, in the year following participant’s vaccination.1
The cohort totaled 1 037 936 children, with 480 498 children in group 1 (aged 5-11 years) and 719 519 adolescents in group 2 (aged 12-17 years). Overall, 55% received at least 1 SARS-CoV-2 vaccine, and 84% of vaccinated participants received ≥2 doses, according to researchers.1
Results showed that the incidence of probable long COVID in the cohort was 4.5% and the incidence of diagnosed long COVID was 0.7%. Investigators estimated that vaccine effectiveness within 12 months against long COVID was 35.4% among children with probable long COVID and 41.7% among those diagnosed with long COVID.1
Razzaghi and colleagues found that vaccine effectiveness was higher for adolescents aged 12-17 years (50.3%) than children aged 5-11 years (23.8%), and higher at 6 months (61.4%) than at 18 months (10.6%).1
Children vaccinated after recovering from COVID-19 who were infected a second time also appeared to benefit, with a calculated vaccine effectiveness of 46% against probable long COVID, reported researchers.1
“This study provides us with important data showing the protective effects of the vaccine against long-haul COVID and suggests that this protection is mostly from preventing visible infections. We hope this means that as vaccines are improved to be more effective against current strains of SARS-CoV-2, their protection against long COVID will get better, too,” said senior author Charles Bailey, MD, PhD, associate professor of pediatrics, Children’s Hospital of Philadelphia, in the press statement. “These retrospective data provide guidance for additional research into the ways long COVID develops, and how we can better protect children and adolescents.”2
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