Iqbal Farooqui, Mithilesh Kumar
Background COVID-19 survivors from both the first wave (ancestral SARS-CoV-2 strain) and the second wave (Delta variant, B.1.617.2) face a shared risk of persistent post-COVID symptoms - collectively termed Post-Acute Sequelae of SARS-CoV-2 (PASC) or Long COVID. Community-based data comparing post-COVID symptom trajectories between wave cohorts across multiple structured follow-up timepoints remain limited in India, particularly in tier-two city settings. This prospective comparative observational study examined and compared post-COVID symptom prevalence between first- and second-wave survivors from urban Hazaribagh, Jharkhand, across six structured contacts spanning 30 months. The primary objective was to compare symptom prevalence between the two wave cohorts at each contact and the secondary objective was to characterise the trajectory of symptom resolution within each cohort across the follow-up period. Methods A total of 601 adults with COVID-19 from urban Hazaribagh were enrolled - 155 from Wave 1 and 446 from Wave 2 - through systematic random sampling from the Integrated Disease Surveillance Programme (IDSP) registers. The sampling intervals (every seventh Wave-1 and every 17th Wave-2 case) were set in proportion to the differing sizes of the two source registers (1,065 and 7,686 confirmed cases, respectively), so as to draw similarly powered, logistically feasible samples from each wave. Seventeen post-COVID symptoms were assessed using a validated semi-structured questionnaire at six structured contacts: Contact 1 (enrolment, Month 0) and five further contacts at six-monthly intervals through Month 30. A symptom present beyond 30 days was recorded as a post-COVID manifestation; Chi-squared tests (Yates'-corrected) and Fisher's exact test were used for inter-wave comparisons; p<0.05 was considered statistically significant. Results Post-COVID symptom burden declined markedly in both cohorts from Contact 1 onwards and remained consistently low through Contact 6. The only statistically significant inter-wave difference at any contact was fatigue at Contact 1 (Wave 1: 12/155 (7.7%) vs. Wave 2: 17/446 (3.8%); p=0.049). No other symptom at any of the six contacts reached statistical significance between wave cohorts (all p>0.05). Fatigue, difficulty in breathing, and rhinorrhoea were the most consistently reported symptoms across contacts, each persisting in fewer than 3% of participants per wave from Contact 3 onwards. Stratified analyses found no sex-based difference in any symptom at any contact; hospitalisation during acute illness and incomplete vaccination status, but not sex, were each associated with higher rates of a small number of symptoms (chiefly difficulty in breathing, chest heaviness, fatigue and rhinorrhoea) at specific contacts. Conclusion Post-COVID symptom persistence is low and broadly comparable between first- and second-wave COVID-19 survivors beyond six months, with fatigue being the only symptom distinguishing the waves, and only at the earliest contact. The convergence of post-COVID trajectories from Contact 2 onwards is consistent with a single, uniform post-COVID follow-up protocol for survivors of both waves, though this comparative design - lacking a SARS-CoV-2-negative reference arm - cannot establish what symptom burden would have occurred in the absence of infection. Fatigue warrants prioritised clinical attention as the most persistent post-COVID symptom in this community setting.