What factors contribute to post-COVID-19 conditions (“long COVID”)? Can vaccination before or after a COVID-19 infection decrease the risk of long COVID?
Throughout the many waves and strains of COVID-19, infections have ranged from asymptomatic to fatal. As early as 2020, however, it was acknowledged that COVID-19 symptoms could linger for months after acute COVID-19 infection.
Common post-acute sequalae of COVID-19, often called “long COVID,” include fatigue, shortness of breath, joint pain, anxiety, and depression. Such symptoms can prove debilitating and significantly deteriorate patients’ quality of life.
Unlike a traditional COVID-19 infection, young and healthy persons can be just as susceptible to long COVID as older, immunocompromised individuals. Overall, the duration and pathophysiology of long COVID vary significantly from person to person, and may also depend on the COVID-19 variant contracted.
A new study, published in JAMA Infectious Diseases, analyzed the factors associated with post-COVID-19 conditions (PCCs) and examined the medical encounters of these long COVID patients.
The role of COVID-19 vaccination, though proven highly protective against acute symptoms, hospitalization, and death, is unknown in its ability to prevent long COVID. “If vaccination either before or after infection decreases the impact of PCCs, there are even stronger arguments for vaccination,” the study authors wrote. “Therefore, further evidence is needed urgently to better clarify the role of vaccination as a potential intervention for PCCs.”
The study objective was to describe long-term experiences after COVID-19 infection and factors that increase the risk of long COVID. The investigators also quantified whether COVID-19 vaccination before versus after infection affected the likelihood of PCCs, as well as the frequency of organ-specific health care visits before and after COVID-19 infection.
The cohort study utilized data from the EPICC study, an investigation approved by the Uniformed Services University review board. Eligibility for EPICC included testing for COVID-19, presenting with a COVID-19-like illness, and/or exposure to a confirmed COVID-19 infection. All participants provided written informed consent.
These specific analyses included 1832 patients, ranging from 18-44 years of age. Participants reporting COVID-19 symptoms recorded the date of symptom onset, severity of symptoms, duration of illness, and, if applicable, duration of hospitalization.
Of the 1832 study patients, 61.0% were male, 77.1% were unvaccinated at the time of their infection, and 70.4% had no comorbidities. A total of 728 participants, 39.7%, had symptoms that lasted 28 days or longer, qualifying them as long COVID patients. Of the long COVID patients, 19.9% (n = 364) had symptoms that lasted 28-89 days, and 19.9% (n = 364) had PCCs that lasted beyond 90 days.
Participants who were unvaccinated when they contracted COVID-19 were more likely to report moderate-to-severe infection, were hospitalized for longer, and were more likely to report symptoms lasting 28 days or more. They also averaged a Charlson Comorbidity score of 5 or greater.
Initially unvaccinated participants who were vaccinated after their COVID-19 infection had a 41% lower risk of PCCs lasting 6 months or longer.
The findings demonstrate the risk of long COVID is exacerbated by more severe acute illness, a higher Charlson Comorbidity score index, and being unvaccinated. Additionally, at 6 months after contracting COVID-19, participants had an elevated risk of pulmonary, diabetes, neurological, and mental health-related medical encounters than before infection.
Given the significant burden of long COVID on patients and the health care system, it is significant to study post-COVID-19 conditions and implement strategies such as post-infection vaccination that may mitigate them.