A recent study published in Nature Communications Medicine has shed light on the long-term effects of COVID-19 in young people, revealing that a significant proportion of teenagers initially diagnosed with Long COVID recover within two years. Meanwhile, research featured in eClinicalMedicine, part of The Lancet Discovery Medicine, demonstrates the efficacy of the BNT162b2 mRNA COVID-19 vaccine (Pfizer-BioNTech) in reducing the incidence of Long COVID in both children and adolescents. These findings offer crucial insights into the trajectory of Long COVID and the protective role of vaccination in this population.
Long-term Recovery from COVID-19
The Nature Communications Medicine study followed 12,632 participants aged 11-17 years, including 943 who tested positive for SARS-CoV-2. The study, part of the National Long COVID in Children and Young People (CloCk) study in England, tracked symptoms at 3, 6, 12, and 24-month intervals after initial infection. Of the 943 participants who tested positive, 233 met the research definition of Long COVID at 3 months. By the 24-month mark, only 68 (7.2%) continued to experience Long COVID symptoms. This indicates that approximately 70% of young people with Long COVID at 3 months had recovered within two years.
Professor Sir Terence Stephenson, the study's chief investigator, noted, "Our findings show that for teenagers who fulfilled our research definition of Long COVID 3 months after a positive test for the COVID virus, the majority have recovered after 2 years. This is good news but we intend to do further research to try to better understand why 68 teenagers had not recovered."
Vaccine Efficacy Against Long COVID
The eClinicalMedicine study assessed the effectiveness of the BNT162b2 mRNA vaccine in preventing Long COVID outcomes during the Delta and Omicron variant periods. The study included 112,590 adolescents during the Delta phase and 188,894 children and 84,735 adolescents during the Omicron phase. Data was gathered from 20 health systems in the RECOVER PCORnet electronic health record program.
The investigators found that during the Delta-dominant period, the mRNA vaccine was 95.4% effective in reducing Long COVID in adolescents. During the Omicron phase, the vaccine's effectiveness was 75.1% in adolescents and 60.1% in children. The study suggests that the vaccine's primary benefit in protecting against Long COVID stems from its ability to reduce the risk of initial SARS-CoV-2 infection.
"Our findings indicated a high overall protective effect of BNT162b2 against long COVID during the period dominated by the Delta variant and moderate protective effects during the Omicron period," the investigators wrote. "The estimated direct effects suggested that beyond the protective role of vaccination against SARS-CoV-2 infection, pre-infection vaccination does not significantly modify the likelihood of Long COVID."
The researchers concluded, "This study profoundly enriches our understanding of the BNT162b2 vaccine’s impact on Long COVID risks within the US pediatric demographic, emphasizing the critical role of vaccination and infection prevention in public health policymaking."
