In a recent study published, researchers in Switzerland investigated the association between post-coronavirus disease 2019 (COVID-19) condition (PCC) six months after infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta or Omicron variant of concern (VOC) and prior COVID-19 vaccination as compared to infection with the SARS-CoV-2 wildtype (WT) strain in non-vaccinated individuals.
PCC, often referred to as 'long COVID,' is a critical COVID-19 complication that has significantly impacted human lives globally. Further investigation on PCC risks post-COVID-19 vaccination and SARS-CoV-2 infections with novel VOCs is needed to guide policy-making, vaccination regimens, and other public health measures.
Results
Data from 1,045 and 305 participants from the Zurich SARS-CoV-2 and Corona Immunitas cohorts, respectively, were analyzed. All individuals were followed up for a median of 183 days. The median ages of the corresponding cohort individuals were 51 years and 43 years, respectively, with 51% and 59% of the corresponding cohorts female.
About 25%, 17%, and 13% of WT-, Delta-, and Omicron-infected individuals, respectively, were affected by PCC six months after their most recent SARS-CoV-2 infection.
Among individuals vaccinated before infection, 15% and 11% experienced PCC after Delta and Omicron infections, respectively. No distinct patterns in PCC symptoms were observed across participants.
Omicron-infected and vaccinated individuals had lower PCC risks than WT-infected and unvaccinated individuals, with an OR 0.4, irrespective of COVID-19 severity. No significant differences were observed in the prevalence of PCC concerning vaccination doses received or the timing of the most recent vaccination, with sensitivity analyses showing similar results.
Strong evidence was obtained for a risk reduction in those documenting one or two PCC symptoms among those vaccinated against COVID-19 and infected with Omicron compared to unvaccinated WT-infected individuals (OR 0.4). Four PCC symptom clusters comprising neurocognitive, systemic, musculoskeletal, and cardiorespiratory symptoms were identified with identical patterns across VOCs, with malaise, headache, fatigue, and smell or taste disturbances prevalent across all clusters.
Of the 221 screened studies, four investigating the association of Delta or Omicron infections and 11 investigating the association of prior vaccination with PCC were included for the final analysis. Two studies reported lower PCC risk with Omicron infections than other VOC infections.
One study found a lower PCC risk with Alpha VOC infection than with WT infection. In contrast, eight studies reported a significantly lower PCC incidence among messenger ribonucleic acid (mRNA) and adenovirus vector vaccine recipients. Nevertheless, three studies found no differences between vaccinated and unvaccinated SARS-CoV-2-infected individuals.
Conclusion
Overall, the study findings showed that Omicron infection and receipt of COVID-19 vaccines reduced the risk of PCC symptoms six months following infection compared to WT infection without prior vaccination.
Source:
https://www.news-medical.net/news/20221002/Vaccinated-individuals-infected-with-Omicron-less-likely-to-experience-long-COVID-symptoms.aspx