The impact of variant and vaccination on SARS-CoV-2 symptomatology: three prospective household cohorts

Ilse Westerhof*, Marieke de Hoog, Margareta Ieven, Christine Lammens, Janko van Beek, Ganna Rozhnova, Dirk Eggink, Sjoerd Euser, Joanne Wildenbeest, Liesbeth Duijts, Marlies van Houten, Herman Goossens, Carlo Giaquinto, Patricia Bruijning‑Verhagen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)


Objectives: We compared age-stratified SARS-CoV-2 symptomatology of wild-type/Alpha vs Omicron BA.1/BA.2 variant infected individuals and the impact of COVID-19 booster vaccination on Omicron symptom burden. Methods: Data from three European prospective household cohorts were used (April 2020 to April 2021 and January to March 2022). Standardized outbreak protocols included (repeated) polymerase chain reaction testing, paired serology, and daily symptom scoring for all household members. Comparative analyses were performed on 346 secondary household cases from both periods. Results: Children <12 years (all unvaccinated) experienced more symptoms and higher severity scores during Omicron compared with wild-type/Alpha period (P ≤0.01). In adults, Omicron disease duration and severity were reduced (P ≤ 0.095). Omicron was associated with lower odds for loss of smell or taste (adjusted odds ratio [aOR]: 0.14; 95% CI 0.03-0.50) and higher but non-significant odds for upper respiratory symptoms, fever, and fatigue (aORs: 1.85-2.23). No differences were observed in disease severity or duration between primary vs booster series vaccinated adults (P ≥0.12). Conclusion: The Omicron variant causes higher symptom burden in children compared with wild-type/Alpha and lower in adults, possibly due to previous vaccination. A shift in symptoms occurred with reduction in loss of smell/taste for Omicron. No additional effect of booster vaccination on Omicron symptom burden was observed.

Original languageEnglish
Pages (from-to)140-147
Number of pages8
JournalInternational Journal of Infectious Diseases
Publication statusPublished - Mar 2023

Bibliographical note

Funding Information:
This work forms part of RECOVER (Rapid European COVID-19 Emergency Response research) and VERDI (SARS-coV2 variants Evaluation in pRegnancy and paeDIatrics cohorts). RECOVER (101003589) is funded by the European Union (EU) Horizon 2020 research and innovation program. VERDI project (101045989) is funded by the EU. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the EU or the European Health and Digital Executive Agency. Neither the EU nor the granting authority can be held responsible for them. In addition, part of the work is funded by ZonMw.

Publisher Copyright:
© 2022 The Author(s)


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