For many, COVID-19 is now perceived as more of an inconvenience than a serious threat, largely due to the immunity developed from vaccinations and prior exposure to the virus.
Nevertheless, research indicates that experiencing multiple COVID-19 infections elevates the risk of developing Long COVID. In what stands as the most extensive study on Long COVID in young individuals to date, scientists led by a University of Pennsylvania team discovered that young people infected with COVID-19 twice were twice as likely as those infected once to manifest Long COVID symptoms impacting vital organs such as the heart, kidneys, and lungs, alongside alterations in taste and smell.
This ongoing research initiative, known as RECOVER, receives funding from the National Institutes of Health and explores the long-term health implications of COVID-19 infections. Yong Chen, a professor of biostatistics and director of the Center for Health AI and Synthesis of Evidence (CHASE) at the University of Pennsylvania, and his colleagues focused on individuals aged 21 and younger to better comprehend how COVID-19 reinfection influences health. Chen states, “People tend to think reinfections don’t matter as much and don’t approach them seriously. Our core message is that reinfections are still significant, and you should take all possible measures to prevent reinfection by taking precautions or wearing a mask.”
The study encompassed data from over 460,000 children, adolescents, and young adults from 40 pediatric hospitals who received a first COVID-19 diagnosis around January 2022; some of these individuals later experienced a second infection. By the close of 2023, researchers compared the group with a single infection to the group with a second infection, concentrating on symptoms resembling Long COVID, including abdominal discomfort, respiratory distress, changes in taste and smell, fatigue, chest pain, myocarditis, or an irregular heartbeat.
Those who experienced a second infection were more than twice as likely as the single-infection group to be diagnosed with Long COVID, and re-infected individuals were nearly three times as likely to report changes in taste and smell compared to those with only one COVID-19 infection. This risk persisted regardless of whether participants were vaccinated or not, and irrespective of the severity of their infections.
However, the term “vaccination status” referred to whether individuals had been vaccinated prior to the study period, not how recently they had received a shot. (The study also commenced before the introduction of the first updated vaccines specifically targeting Omicron.) The authors emphasize that these findings do not imply that vaccines are ineffective in reducing the risk of Long COVID. Rather, the data demonstrates that vaccinated children were substantially less prone to contracting COVID-19 in the first instance and were also less likely to experience reinfection when compared to unvaccinated children.
According to Chen, getting vaccinated represents a vital initial step in safeguarding against the potential onset of Long COVID.
Nonetheless, the study reveals that even for vaccinated individuals, reinfection poses a considerable risk, effectively doubling the probability of developing Long COVID compared to experiencing just one infection.
“The central message revolves around how seriously one should regard the potential risk of acquiring a second COVID-19 infection,” Chen asserts. These findings, corroborated by other research, suggest a possible cumulative detrimental effect of repeated COVID-19 infections on the body, with scientists actively working to understand these potential long-term consequences more thoroughly. Chen’s work also continues to investigate the impact of vaccination following a first infection, not only on the risk of additional infections but also on the development of Long COVID.
