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. 2022 Oct 10:10:1006631.
doi: 10.3389/fpubh.2022.1006631. eCollection 2022.

Rapid investigation of BA.4/BA.5 cases in France

Alain-Claude Kouamen  1 , Helena Da Cruz  2 , Mohamed Hamidouche  3 , Anais Lamy  4 , Anna Lloyd  5 , Javier Castro Alvarez  1 , Mathilde Roussel  6 , Laurence Josset  7 , Vincent Enouf  8 , Charlotte Felici  9 , Georges Dos Santos  10 , Justine Schaeffer  1 , Anna Maisa  1 ; Regional COVID-19 Investigation Group; Laboratory Group
Collaborators, Affiliations

Rapid investigation of BA.4/BA.5 cases in France

Alain-Claude Kouamen et al. Front Public Health. .

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.

Keywords: BA.4; BA.5; Omicron; SARS-CoV-2; hospitalization; symptoms; variant.

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Conflict of interest statement

Author MR was employed by Cerba HealthCare. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Proportion of age groups (left panel) and symptoms (right panel) of BA.4/BA.5 cases compared to previously investigated BA.1 cases. Absolute numbers of cases are shown beside the bars.
See this image and copyright information in PMC

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