Vaccination with an mRNA COVID-19 vaccine prior to infection with the SARS-CoV-2 omicron variant may convey protection from long COVID symptoms in children.
These findings, presented by Anna R. Yousaf, MD, of the Centers for Disease Control and Prevention at IDWeek 2023, may have implications for pediatric vaccination against COVID-19, especially in increasing vaccine uptake and reducing vaccine hesitancy.
Reports of symptoms of "long COVID" have been pervasive, with approximately 20% to 30% of individuals who contract COVID-19 reporting prolonged symptoms 3 to 6 months following infection, with severity ranging from mildly inconvenient to very disruptive. Recent studies have shown that this rate is about 1% to 3% in children. Although data suggests that COVID-19 vaccination may reduce risk of long COVID in adults, data in the pediatric population is very limited.
For this study, participants (aged 5 to 17 years) were derived from the Pediatric Research Observing Trends and Exposures in COVID-19 Timelines (PROTECT) cohort and were categorized as a case if they had confirmed COVID-19 infection and at least 1 reported post-COVID-19 condition (PCC) or a control if they had confirmed COVID-19 with no reported PCC. Participants were considered vaccinated if they had completed at least 1 mRNA COVID-19 vaccination series at least 14 days or more prior to infection with the omicron variant.
- Protection from Long COVID in Children: Vaccination with an mRNA COVID-19 vaccine prior to SARS-CoV-2 omicron variant infection appears to offer protection against long COVID symptoms in children.
- Implications for Pediatric Vaccination: These findings may help increase vaccine acceptance and uptake in children.
- Benefit May Be Underestimated: The study only included those infected with COVID-19 and therefore may underestimate the impact that vaccination and infection prevention has on risk of PCC.
Ultimately, 622 participants who tested positive completed serial surveys about new or ongoing PCC lasting at least 1 month from the time of their positive COVID-19 test. The survey asked about duration of symptom(s): 1-2 months; 3-4 months; 5-6 months; or 6 months of longer; as well as the impact that these symptoms had on their daily activities. PCCs were divided into respiratory and non-respiratory (including general, neurologic, cardiac, gastrointestinal, or other).
Among the participants, 67% were vaccinated. Children aged 12 to 18 years, those of non-Hispanic Asian and White race/ethnicity, and those with excellent/very good self-rated baseline health who reported symptomatic COVID-19 infection were more likely to be vaccinated.
Overall, 5% of participants reported a PCC on the survey, which was completed a median of 203.7 days post-infection. Children of non-Hispanic Black race/ethnicity and good/fair/poor self-rated health at baseline were more likely to report a PCC. Comparing those with and without PCC symptoms, those who were vaccinated were 34% less likely to to report >1 PCC symptom (aOR 0.66, 95% CI: 0.43-0.99); 48% less likely to report >2 PCC symptoms (aOR 0.52, 95% CI: 0.32-0.83); and 47% less likely to report respiratory PCC symptoms (aOR 0.53, 95% CI: 0.33-0.87). Similarly, those who were vaccinated were 38% less likely to report a PCC impacting their daily activities (aOR 0.62; 95% CI: 0.21-1.83).
The investigators noted that given that all participants were positive for COVID-19 infection, the study results may underestimate the reduction in likelihood of PCC associated with vaccination as it fails to account for COVID-19 infection prevention. They also pointed out additional limitations, including recall bias on the survey and a study population that was mostly non-Hispanic white, which may limit the generalizability of the findings.
"These data support COVID-19 vaccination in children and were presented at the ACIP meeting and taken into consideration when recommending boosters in children," Yousaf said during her presentation. "[The findings] may also increase vaccine acceptance and uptake in a population that does not typically experience severe COVID-19 illness"
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Yousaf AR, Mak J, Gwynn L, et al. COVID-19 mRNA Vaccination Reduces the Occurrence of Post-COVID Conditions in U.S. Children Aged 5-17 Years Following Omicron SARS-CoV-2 Infection, July 2021-September 2022. Presented at: IDWeek 2023. October 11-14, 2023; Boston, MA. Abstract 1935.