Preprint Incidence of Long COVID Following Reinfection with COVID-19, 2025, Brannock et al.

SNT Gatchaman

Senior Member (Voting Rights)
Staff member
Incidence of Long COVID Following Reinfection with COVID-19
M Daniel Brannock; Emily Hadley; Alexander Preiss; Megan L Fitzgerald; Nita Jain; Emily Taylor; Andrew Wylam; Yun J Yoo; Elaine Hill; Richard A Moffitt; N3C Consortium; RECOVER Consortium

BACKGROUND
COVID-19 reinfections have emerged as a critical concern, particularly in relation to post-acute sequelae of SARS-CoV-2 infection, commonly known as long COVID. Long COVID is known to manifest diverse, debilitating symptoms across all demographics. Limited studies have investigated the causal relationship of COVID-19 reinfections and long COVID.

METHODS
We leveraged demographically diverse electronic health records from the COVID-19 enclave of the National Clinical Cohort Collaborative, part of the RECOVER initiative, to create a matched cohort of reinfected and control adults. All participants had at least one documented COVID-19 infection. We used one-to-one coarsened exact matching on sex, race/ethnicity, age, healthcare utilization, existing comorbidities, site of care, and the timing and severity of first infection. Index dates were assigned to each matched pair as the date of reinfection for the reinfected case. Long COVID was defined using a machine learning computable phenotype trained on clinically diagnosed long COVID cases. Cumulative incidence one year after index was calculated using an Aalen-Johansen estimator. Risk ratios were calculated by taking the ratio of long COVID incidence among reinfected and control cases.

RESULTS
We found that reinfection resulted in a significantly higher risk of long COVID compared to not being reinfected (risk ratio, 1.35, 95% CI, 1.32-1.39; risk difference, 0.029, 95% CI, 0.027-0.031). This effect was consistent across most stratifications.

CONCLUSIONS
We found that COVID-19 reinfection resulted in a roughly 35% increase in the incidence of long COVID in a matched cohort using observational electronic health records.

Link | PDF | Preprint: MedRxiv | Open Access
 
Article from CIDRAP today:
COVID reinfection may raise risk of persistent symptoms by 35%

This quote about a sub analysis from the study seems important. I'm curious about how well vaccinations protect against Long Covid as infections are accumulating..

"Those vaccinated between first infection and index faced lower risks of long COVID from reinfection than those only vaccinated prior to their first infection, suggesting that more recent vaccinations may lower the risk of long COVID following reinfections," the study authors wrote. "However, this effect was not consistent across all groups."

"Vaccinated individuals tended to be older with more comorbidities and utilization, resulting in higher overall incidences of long COVID," they added. "More research is needed to discern how vaccination modulates the likelihood of a reinfection to lead to long COVID."
 
This quote about a sub analysis from the study seems important. I'm curious about how well vaccinations protect against Long Covid as infections are accumulating..
Yes, especially as it might indicate there's a case for continued vaccination:

suggesting that more recent vaccinations may lower the risk of long COVID following reinfections
It would probably need a lot more work to be sure of that, though.
 
Back
Top Bottom