Vaccinated teens face lower risk of long COVID, study suggests

Tanayott Thaweethai, PhD and Andrea S. Foulkes, ScD, both of Massachusetts General Hospital Biostatistics, are the lead and senior authors of a paper published in Vaccine, “Preventive effect of vaccination on long COVID in adolescents with SARS-CoV-2 infection.”
 

Q: How would you summarize your study for a lay audience?

While it is already known that COVID-19 vaccination lowers recipients’ chances of contracting COVID-19, or becoming seriously ill from the infection if they do, our study focused on the vaccine’s longer-term effects. Specifically, we studied a cohort of adolescents and asked, does COVID-19 vaccination do more than just prevent infection? Does it also keep regular cases of COVID from progressing to chronic cases, called long COVID, in this population?

Although long COVID can affect multiple organ systems and significantly reduce quality of life, it’s understudied in pediatrics — a knowledge gap that we set out to address in this work.
 

Q: What methods or approach did you use?

We studied children ages 12–17, classified as adolescents, who were part of a large national research initiative called Researching COVID to Enhance Recovery (RECOVER). Some participants also came from the Adolescent Brain and Cognitive Development (ABCD) study and participated in RECOVER.

We looked at whether adolescents who had received at least one COVID-19 vaccination within the six months prior to their first infection had a different rate of developing long COVID than those who had not been vaccinated at all before infection. We made sure that adolescents in the study who were vaccinated were matched to adolescents who were infected at the same time and were also vaccine-eligible, but did not get vaccinated. This means that we excluded adolescents who were infected with the very earliest COVID variants, as adolescents were not eligible to be vaccinated back then. We collected data from caregivers and defined long COVID using our previously developed, adolescent-specific Long COVID Research Index.
 

Q: What did you find?

We found that the risk of long COVID was 36% lower in vaccinated participants compared to never-vaccinated participants. This was based on our analysis of the 1,231 adolescents included in our matched cohort (507 unvaccinated and 724 vaccinated). Our findings were similar after adjusting for caregiver education level, COVID variant and residence in a medically underserved area, all of which were potential confounders in the study.

Because long COVID can seriously affect children’s health and well-being, and treatment options are currently limited, our study shows recent vaccination offers an important added layer of protection. Not only does the COVID vaccine lower the chance of infection and serious illness, but it also appears to reduce the risk of acute cases progressing to chronic conditions — making it relatively unique among vaccines.
 

Q: What are the next steps?

Future work should evaluate the impact of vaccines administered after infection, its potential role as a treatment for long COVID and its effects across other age groups.