Oral nirmatrelvir/ritonavir is a treatment for COVID-19, but whether treatment during the acute phase reduces the risk of developing Long COVID is unknown.
Using the Covid Citizen Science (CCS) online cohort, we surveyed individuals who reported their first SARS-CoV-2 positive test between March and August 2022 regarding Long COVID symptoms. We excluded those who were pregnant, unvaccinated, hospitalized for COVID-19, or received other antiviral therapy. The primary exposure was oral nirmatrelvir/ritonavir. The primary outcome was the presence of any Long COVID symptoms reported on cross-sectional surveys in November and December 2022. We used propensity-score models and inverse probability of treatment weighting to adjust for differences in treatment propensity. Our secondary question was whether symptom or test positivity rebound were associated with Long COVID.
4684 individuals met the eligibility criteria, of whom 988 (21.1%) were treated and 3696 (78.9%) were untreated; 353/988 (35.7%) treated and 1258/3696 (34.0%) untreated responded to the survey. Median age was 55 years and 66% were female. We did not identify an association between nirmatrelvir/ritonavir treatment and Long COVID symptoms (OR 1.15; 95%CI 0.80-1.64). Among n=666 treated with nirmatrelvir/ritonavir who responded who responded to questions about rebound, rebound symptoms or test positivity were not associated with Long COVID symptoms (OR 1.34; 95%CI 0.74-2.41; p=0.33).
Within this cohort, treatment with nirmatrelvir/ritonavir among vaccinated, non-hospitalized individuals was not associated with lower prevalence of Long COVID symptoms or severity of Long COVID. Experiencing rebound symptoms or test positivity is not strongly associated with developing Long COVID.