AUTHOR=Kouamen Alain-Claude , Da Cruz Helena , Hamidouche Mohamed , Lamy Anais , Lloyd Anna , Castro Alvarez Javier , Roussel Mathilde , Josset Laurence , Enouf Vincent , Felici Charlotte , Dos Santos Georges , Schaeffer Justine , Maisa Anna , Regional COVID-19 Investigation Group , Laboratory Group , Picard Gwenola , Michée Géraud Vikpognon , Brembilla Alice , Dahl Ellen , Chent Souhaila , Mercier Alizé , Gbaguidi Gwladys Nadia , Grenier Carine , Riondel Adeline , Caroline Huchet-Kervella , Leila Bekheira , Stephan Kemeny , Vignault Claire , Trémeaux Pauline , Fournier Pierre-Edouard , Vallet Sophie , Descamps Diane , Chollet Lionel , Dossou Nefert , Moisan Alice , Soares Anais , Jaffar Bandjee Marie Christine , de Rougement Alexis , Henquell Cécile , Lavergne Anne TITLE=Rapid investigation of BA.4/BA.5 cases in France JOURNAL=Frontiers in Public Health VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.1006631 DOI=10.3389/fpubh.2022.1006631 ISSN=2296-2565 ABSTRACT=Aim

We aimed to describe the characteristics of individuals infected by BA.4 or BA.5 in France in comparison to BA.1, and analyze the factors associated with hospitalization among BA.4 and BA.5 cases.

Methods

A standardized questionnaire was used to collect information on confirmed and probable Omicron cases. Hospitalization risk factors among BA.4/BA.5 cases were analyzed using Poisson regression. Variables with a p-value below 0.2 in the univariate analysis and a priori confounders were included in the multivariable regression model.

Results

The median age of the 301 cases investigated was 47 years and 97% of cases were symptomatic. The most common clinical signs were asthenia/fatigue (75.7%), cough (58.3%), fever (58.3%), headache (52.1%) and rhinorrhea (50.7%). Twelve cases were hospitalized, and 27.1% reported risk factors. No admissions to intensive care and no deaths were reported. Vaccination status was available for 292 cases, 20.9% were unvaccinated, 1.4% had received one dose, 38.3% two doses and 39.4% three doses. Cases presenting at least one risk factor were almost seventeen times more likely to be hospitalized than those with no risk factors (aRR = 16.72 [95% CI2.59–326.86]).

Conclusion

Despite the longer duration of and the differences in symptoms and their possible immune escape, BA.4/BA.5 Omicron sub-lineages globally showed no severe clinical presentation. The presence of at least one risk factor for severe disease significantly increased the risk of hospitalization for those infected with BA.4 or BA.5.