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We assessed the protection conferred by naturally-acquired, vaccine-induced and hybrid immunity during the concomitant Omicron and Delta epidemic waves in France on symptomatic infection and severe COVID-19. The greatest levels of protection against both variants were provided by hybrid immunity. Protection against Omicron symptomatic infections was systematically lower and waned at higher speed than against Delta in those vaccinated. In contrast, there were little differences in variant-specific protection against severe inpatient outcomes in symptomatic individuals.


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  1. Santé publique France (SPF). COVID-19 - Point épidémiologique hebdomadaire du 23 décembre 2021. [COVID-19 weekly epidemiological report of 23 December 2021]. Saint-Maurice: SPF. 23 Dec 2021. French. Available from: https://www.santepubliquefrance.fr/content/download/400096/3305200
  2. European Centre for Disease Prevention and Control (ECDC). Reinfection with SARS-CoV-2: implementation of a surveillance case definition within the EU/EEA. 8 April 2021. ECDC: Stockholm, 2021. Available from: https://www.ecdc.europa.eu/en/publications-data/reinfection-sars-cov-2-implementation-surveillance-case-definition-within-eueea
  3. Suarez Castillo M, Khaoua H, Courtejoie N. 2022. Vaccine effectiveness and duration of protection against symptomatic and severe Covid-19 during the first year of vaccination in France MedRxiv
  4. Pilz S, Theiler-Schwetz V, Trummer C, Krause R, Ioannidis JPA. SARS-CoV-2 reinfections: Overview of efficacy and duration of natural and hybrid immunity. Environ Res. 2022;209:112911.  https://doi.org/10.1016/j.envres.2022.112911  PMID: 35149106 
  5. Andrews N, Stowe J, Kirsebom F, Toffa S, Rickeard T, Gallagher E, et al. Covid-19 vaccine effectiveness against the omicron (B. 1.1. 529) variant. N Engl J Med. 2022;NEJMoa2119451.  https://doi.org/10.1056/NEJMoa2119451  PMID: 35249272 
  6. Nyberg T, Ferguson NM, Nash SG, Webster HH, Flaxman S, Andrews N, et al. , COVID-19 Genomics UK (COG-UK) consortium. Comparative analysis of the risks of hospitalisation and death associated with SARS-CoV-2 omicron (B.1.1.529) and delta (B.1.617.2) variants in England: a cohort study. Lancet. 2022;399(10332):1303-12.  https://doi.org/10.1016/S0140-6736(22)00462-7  PMID: 35305296 
  7. Altarawneh HN, Chemaitelly H, Hasan MR, Ayoub HH, Qassim S, AlMukdad S, et al. Protection against the Omicron Variant from Previous SARS-CoV-2 Infection. N Engl J Med. 2022;386(13):1288-90.  https://doi.org/10.1056/NEJMc2200133  PMID: 35139269 
  8. Tseng HF, Ackerson BK, Luo Y, Sy LS, Talarico CA, Tian Y, et al. Effectiveness of mRNA-1273 against SARS-CoV-2 Omicron and Delta variants. Nat Med. 2022;2022(Feb):21.  https://doi.org/10.1038/s41591-022-01753-y  PMID: 35189624 
  9. Shrestha NK, Shrestha P, Burke PC, Nowacki AS, Terpeluk P, Gordon SM. 2022. Coronavirus Disease 2019 (COVID-19) Vaccine Boosting in Persons Already Protected by Natural or Vaccine-Induced Immunity. medRxiv . https://doi.org/10.1101/2022.02.10.22270744 
  10. Jackson ML, Nelson JC. The test-negative design for estimating influenza vaccine effectiveness. Vaccine. 2013;31(17):2165-8.  https://doi.org/10.1016/j.vaccine.2013.02.053  PMID: 23499601 
  11. Dean NE, Hogan JW, Schnitzer ME. Covid-19 Vaccine Effectiveness and the Test-Negative Design. N Engl J Med. 2021;385(15):1431-3.  https://doi.org/10.1056/NEJMe2113151  PMID: 34496195 
  12. Kahn F, Bonander C, Moghaddassi M, Rasmussen M, Malmqvist U, Inghammar M, et al. Risk of severe COVID-19 from the Delta and Omicron variants in relation to vaccination status, sex, age and comorbidities - surveillance results from southern Sweden, July 2021 to January 2022. Euro Surveill. 2022;27(9):2200121.  https://doi.org/10.2807/1560-7917.ES.2022.27.9.2200121  PMID: 35241215 
  13. Auvigne V, Vaux S, Le Strat Y, Schaeffer J, Fournier L, Tamandjou C, et al. 2022. Serious hospital events following symptomatic infection with Sars-CoV-2 Omicron and Delta variants: an exposed-unexposed cohort study in December 2021 from the COVID-19 surveillance databases in France. medRxiv.  https://doi.org/10.1101/2022.02.02.22269952 
  14. Santé Publique France (SPF). CNR Virus des infections respiratoires, Institut Pasteur, Hospices civil de Lyon. Mise à jour de l’analyse de risque sur les variants émergents du SARS-CoV-2 du 01/12/2021 réalisée conjointement par Santé publique France et le CNR des virus des infections respiratoires. [15/12/2021 update of the 01/12/2021 SARS-CoV-2-emerging-variant risk analysis conducted jointly by the French Public Health Agency and the National Reference Laboratory for respiratory viruses.] Saint-Maurice: SPF; 15 Dec 2021. Available from: https://www.santepubliquefrance.fr/media/files/01-maladies-et-traumatismes/maladies-et-infections-respiratoires/infection-a-coronavirus/analyse-de-risque-des-variants-emergents-de-sars-cov-2-maj-15-12-2021

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