Thematic File: COVID-19
From the onset of the COVID-19 health crisis and the containment measures announced by the President of the Republic, EPI-PHARE reaffirmed to its institutional members its unwavering commitment and full mobilization in fulfilling its mission during this unprecedented period. All EPI-PHARE staff remained actively engaged, including those in direct contact with patients within healthcare facilities, ensuring the continuity of clinical activities.
While maintaining its core operations, EPI-PHARE also redirected a significant portion of its work program to address issues related to the COVID-19 epidemic. Since the first lockdown in March 2020, EPI-PHARE has leveraged its expertise to quantify and characterize the use and risks of health products affected by this crisis. In doing so, it has provided critical insights and evidence to public authorities, in line with its targeted program focused on emergency situations and health crises.
Specifically, EPI-PHARE initiated and coordinated studies on the use of health products in France during and after lockdown, the risk of severe COVID-19 associated with certain medications, and the analysis of factors linked to COVID-19 risk in the general French population—including residual risks post-vaccination. It also contributed to the pharmacovigilance component of the enhanced surveillance system for COVID-19 vaccines, conducting both risk and effectiveness studies.
The findings from EPI-PHARE’s research since the beginning of the pandemic have been widely utilized by health authorities to inform decision-making. These results provided timely support for measures such as continuing infant vaccination and the diagnosis and treatment of certain diseases during the epidemic. They also guided the adaptation of France’s COVID-19 vaccination strategy, prioritizing high-risk patient groups—such as those with Down syndrome—who faced elevated risks of hospitalization or death from COVID-19. Additionally, the data enabled French authorities to adjust vaccination recommendations after quantifying the risk of myocarditis in individuals under 30 following mRNA vaccination.
Beyond making its study reports publicly available (in French only), EPI-PHARE prioritized publishing its findings in international peer-reviewed journals. This dual approach aimed to strengthen the scientific credibility of its work through peer review and to contribute transparently to the global scientific effort against the pandemic. Since the outbreak began, EPI-PHARE has released all its reports (in French, on the french version of this website) and published numerous articles in international journals. A comprehensive overview of its COVID-19 studies was also featured in Therapies, the journal of the French Society of Pharmacology and Therapeutics (SFPT).
You will find below all the references of peer-reviewed articles published by EPI-PHARE on the topic of COVID-19.
- Billioti de Gage, S., Drouin, J., Desplas, D., Cuenot, F., Dray-Spira, R., Weill, A., & Zureik, M. (2021). Intravitreal Anti–Vascular Endothelial Growth Factor Use in France During the Coronavirus Disease 2019 Pandemic. JAMA Ophthalmology, 139(2), 240‑242. https://doi.org/10.1001/jamaophthalmol.2020.5594
- Dufour, E., Baheux, C., & Zureik, M. (2022). Routine surgeries during the COVID-19 pandemic : A French nationwide cohort study. Annals of Medicine and Surgery, 77, 103721. https://doi.org/10.1016/j.amsu.2022.103721
- Meyer, A., Drouin, J., Zureik, M., Weill, A., & Dray-Spira, R. (2021). Colonoscopy in France during the COVID-19 pandemic. International Journal of Colorectal Disease, 36, 1073‑1075. https://doi.org/10.1007/s00384-020-03816-3
- Penso, L., Dray‐Spira, R., Weill, A., Zureik, M., & Sbidian, E. (2021). Drop in biological initiation for patients with psoriasis during the COVID-pandemic. British Journal of Dermatology, 185(3), 671‑673. https://doi.org/10.1111/bjd.20406
- Roland, N., Drouin, J., Desplas, D., Cuenot, F., Dray-Spira, R., Weill, A., & Zureik, M. (2021). Effects of the Coronavirus Disease 2019 (COVID-19) Lockdown on the Use of Contraceptives and Ovulation Inductors in France. Obstetrics & Gynecology, 137(3), 415‑417. https://doi.org/10.1097/AOG.0000000000004281
- Roland, N., Drouin, J., Desplas, D., Duranteau, L., Cuenot, F., Dray-Spira, R., Weill, A., & Zureik, M. (2022). Impact of Coronavirus Disease 2019 (COVID-19) On Contraception Use in 2020 and up until the end of April 2021 in France. Contraception, 108, 50‑55. https://doi.org/10.1016/j.contraception.2021.12.002
- Roland, N., Drouin, J., Desplas, D., Duranteau, L., Cuenot, F., Dray-Spira, R., Weill, A., & Zureik, M. (2023). Impact of coronavirus disease 2019 on contraception use in France. Therapies, 78(5), 593‑603. https://doi.org/10.1016/j.therap.2023.01.002
- Taine, M., Offredo, L., Drouin, J., Toubiana, J., Weill, A., Zureik, M., & Dray-Spira, R. (2021). Mandatory Infant Vaccinations in France During the COVID-19 Pandemic in 2020. Frontiers in Pediatrics, 9. https://doi.org/10.3389/fped.2021.666848
- Botton, J., Semenzato, L., Dupouy, J., Dray-Spira, R., Weill, A., Saint-Lary, O., & Zureik, M. (2022). No association of low-dose aspirin with severe COVID-19 in France : A cohort of 31.1 million people without cardiovascular disease. Research and Practice in Thrombosis and Haemostasis, 6(4), e12743. https://doi.org/10.1002/rth2.12743
- Bouillon, K., Baricault, B., Semenzato, L., Botton, J., Bertrand, M., Drouin, J., Dray‐Spira, R., Weill, A., & Zureik, M. (2022). Association of Statins for Primary Prevention of Cardiovascular Diseases With Hospitalization for COVID‐19 : A Nationwide Matched Population‐Based Cohort Study. Journal of the American Heart Association, 11(12), e023357. https://doi.org/10.1161/JAHA.121.023357
- Kolla, E., Weill, A., Desplas, D., Semenzato, L., Zureik, M., & Grimaldi, L. (2022). Does Measles, Mumps, and Rubella (MMR) Vaccination Protect against COVID-19 Outcomes : A Nationwide Cohort Study. Vaccines, 10(11), Article 11. https://doi.org/10.3390/vaccines10111938
- Kolla, E., Weill, A., Zaidan, M., De Martin, E., Colin De Verdiere, S., Semenzato, L., Zureik, M., & Grimaldi, L. (2023). COVID-19 Hospitalization in Solid Organ Transplant Recipients on Immunosuppressive Therapy. JAMA Network Open, 6(11), e2342006. https://doi.org/10.1001/jamanetworkopen.2023.42006
- Meyer, A., Semenzato, L., Zureik, M., Weill, A., Carbonnel, F., & Dray-Spira, R. (2021). Risk of severe COVID-19 in patients treated with IBD medications : A French nationwide study. Alimentary Pharmacology & Therapeutics, 54(2), 160‑166. https://doi.org/10.1111/apt.16410
- Penso, L., Dray-Spira, R., Weill, A., Zureik, M., & Sbidian, E. (2022). Psoriasis-related treatment exposure and hospitalization or in-hospital mortality due to COVID-19 during the first and second wave of the pandemic : Cohort study of 1,326,312 patients in France. British Journal of Dermatology, 186(1), 59‑68. https://doi.org/10.1111/bjd.20659
- Sbidian, E., Penso, L., Herlemont, P., Botton, J., Baricault, B., Semenzato, L., Drouin, J., Weill, A., Dray-Spira, R., & Zureik, M. (2023). Comment on ‘Baseline use of hydroxychloroquine in systemic lupus erythematosus does not preclude SARS-CoV-2 infection and severe COVID-19’ by Konig et al. Long-term exposure to hydroxychloroquine or chloroquine and the risk of hospitalisation with COVID-19 : A nationwide, observational cohort study in 54 873 exposed individuals and 155 689 matched unexposed individuals in France. Annals of the Rheumatic Diseases, 82(5), e117. https://doi.org/10.1136/annrheumdis-2020-218647
- Semenzato Laura, Botton Jérémie, Drouin Jérôme, Baricault Bérangère, Vabre Clémentine, Cuenot François, Penso Laetitia, Herlemont Philippe, Sbidian Emilie, Weill Alain, Dray-Spira Rosemary, & Zureik Mahmoud. (2021). Antihypertensive Drugs and COVID-19 Risk. Hypertension, 77(3), 833‑842. https://doi.org/10.1161/HYPERTENSIONAHA.120.16314
- Semenzato, L., Botton, J., Drouin, J., Baricault, B., Bertrand, M., Jabagi, M.-J., Cuenot, F., Vu, S. L., Dray-Spira, R., Weill, A., & Zureik, M. (2022). Characteristics associated with the residual risk of severe COVID-19 after a complete vaccination schedule : A cohort study of 28 million people in France. The Lancet Regional Health – Europe, 19, 100441. https://doi.org/10.1016/j.lanepe.2022.100441
- Semenzato, L., Botton, J., Drouin, J., Cuenot, F., Dray-Spira, R., Weill, A., & Zureik, M. (2021). Chronic diseases, health conditions and risk of COVID-19-related hospitalization and in-hospital mortality during the first wave of the epidemic in France : A cohort study of 66 million people. The Lancet Regional Health – Europe, 8, 100158. https://doi.org/10.1016/j.lanepe.2021.100158
- Tubiana, S., Rontani, M., Herlemont, P., Dray-Spira, R., Zureik, M., Weill, A., Duval, X., & Burdet, C. (2025). Long-term health outcomes following hospitalisation for COVID-19 : A 30- month cohort analysis. Infectious Diseases, 57(5), 433‑443. https://doi.org/10.1080/23744235.2025.2452862
- Turpin, A., Semenzato, L., Stephane, S. L. V., Jabagi, M.-J., Bouillon, K., Drouin, J., Bertrand, M., Kanagaratnam, L., Weill, A., Dray-Spira, R., Zureik, M., & Botton, J. (2024). Risk factors for COVID-19 hospitalisation after booster vaccination during the Omicron period : A French nationwide cohort study. Journal of Infection and Public Health. https://doi.org/10.1016/j.jiph.2024.05.007
- Dugerdil, A., Semenzato, L., Weill, A., Zureik, M., & Flahault, A. (2023). Severe SARS-CoV-2 infection as a marker of undiagnosed cancer : A population-based study. Scientific Reports, 13(1), Article 1. https://doi.org/10.1038/s41598-023-36013-7
Use of COVID-19 Vaccines
- Bernard, C., Drouin, J., Le Vu, S., Botton, J., Semenzato, L., Bertrand, M., Jabagi, M.-J., Miranda, S., Dray-Spira, R., Weill, A., & Zureik, M. (2025). COVID-19 vaccination rates among pregnant women in France : A nationwide cohort study. Vaccine, 53, 127070. https://doi.org/10.1016/j.vaccine.2025.127070
- Kolla, E., Weill, A., Zureik, M., & Grimaldi, L. (2024). Étude des déterminants de la vaccination contre la Covid-19 chez les enfants âgés de 5-11 ans, France, 2021-2023. Bulletin Epidémiologique Hebdomadaire, 25, 571‑581. http://beh.santepubliquefrance.fr/beh/2024/25/2024_25_2.html
Vaccine Effectiveness Against Severe Forms of COVID-19
- Botton, J., Dray-Spira, R., Baricault, B., Drouin, J., Bertrand, M., Jabagi, M.-J., Weill, A., & Zureik, M. (2022). Reduced risk of severe COVID-19 in more than 1.4 million elderly people aged 75 years and older vaccinated with mRNA-based vaccines. Vaccine, 40, 414‑417. https://doi.org/10.1016/j.vaccine.2021.12.009
- Botton, J., Semenzato, L., Jabagi, M.-J., Baricault, B., Weill, A., Dray-Spira, R., & Zureik, M. (2022). Effectiveness of Ad26.COV2.S Vaccine vs BNT162b2 Vaccine for COVID-19 Hospitalizations. JAMA Network Open, 5(3), e220868. https://doi.org/10.1001/jamanetworkopen.2022.0868
- Bouillon, K., Baricault, B., Botton, J., Jabagi, J., Bertrand, M., Semenzato, L., Vu, S. L., Drouin, J., Dray, R., Weill, A., & Zureik, M. (2022). Effectiveness of BNT162b2, mRNA-1273, and ChAdOx1-S vaccines against severe covid-19 outcomes in a nationwide mass vaccination setting : Cohort study. BMJ Medicine, 1:e000104. https://doi.org/10.1136/bmjmed-2021-000104
- Semenzato, L., Botton, J., Baricault, B., Deloumeaux, J., Joachim, C., Sylvestre, E., Dray-Spira, R., Weill, A., & Zureik, M. (2022). Vaccine effectiveness against severe COVID-19 outcomes within the French overseas territories : A cohort study of 2-doses vaccinated individuals matched to unvaccinated ones followed up until September 2021 and based on the National Health Data System. PLOS ONE, 17(9), e0274309. https://doi.org/10.1371/journal.pone.0274309
- Semenzato, L., Botton, J., Le Vu, S., Jabagi, M.-J., Cuenot, F., Drouin, J., Dray-Spira, R., Weill, A., & Zureik, M. (2023). Protection of Covid-19 vaccination against hospitalisation during the era of Omicron BA.4 and BA.5 predominance : A nationwide case-control study based on the French National Health Data System. Open Forum Infectious Diseases, 10(10), ofad460. https://doi.org/10.1093/ofid/ofad460
Vaccine-Associated Risks
- Botton, J., Dray-Spira, R., Baricault, B., Drouin, J., Bertrand, M., Jabagi, M.-J., Weill, A., & Zureik, M. (2022). Reduced risk of severe COVID-19 in more than 1.4 million elderly people aged 75 years and older vaccinated with mRNA-based vaccines. Vaccine, 40, 414‑417. https://doi.org/10.1016/j.vaccine.2021.12.009
- Botton, J., Semenzato, L., Jabagi, M.-J., Baricault, B., Weill, A., Dray-Spira, R., & Zureik, M. (2022). Effectiveness of Ad26.COV2.S Vaccine vs BNT162b2 Vaccine for COVID-19 Hospitalizations. JAMA Network Open, 5(3), e220868. https://doi.org/10.1001/jamanetworkopen.2022.0868
- Bouillon, K., Baricault, B., Botton, J., Jabagi, J., Bertrand, M., Semenzato, L., Vu, S. L., Drouin, J., Dray, R., Weill, A., & Zureik, M. (2022). Effectiveness of BNT162b2, mRNA-1273, and ChAdOx1-S vaccines against severe covid-19 outcomes in a nationwide mass vaccination setting : Cohort study. BMJ Medicine, 1:e000104. https://doi.org/10.1136/bmjmed-2021-000104
- Semenzato, L., Botton, J., Baricault, B., Deloumeaux, J., Joachim, C., Sylvestre, E., Dray-Spira, R., Weill, A., & Zureik, M. (2022). Vaccine effectiveness against severe COVID-19 outcomes within the French overseas territories : A cohort study of 2-doses vaccinated individuals matched to unvaccinated ones followed up until September 2021 and based on the National Health Data System. PLOS ONE, 17(9), e0274309. https://doi.org/10.1371/journal.pone.0274309
- Semenzato, L., Botton, J., Le Vu, S., Jabagi, M.-J., Cuenot, F., Drouin, J., Dray-Spira, R., Weill, A., & Zureik, M. (2023). Protection of Covid-19 vaccination against hospitalisation during the era of Omicron BA.4 and BA.5 predominance : A nationwide case-control study based on the French National Health Data System. Open Forum Infectious Diseases, 10(10), ofad460. https://doi.org/10.1093/ofid/ofad460