In Week 11 (March 14–20), the spread of SARS-CoV-2 accelerated across the country. The incidence rate continued to rise (+36%) to reach 937 per 100,000 people nationwide. It was highest among those aged 6–14 and 30–49, where it exceeded 1,000 per 100,000, but the sharpest increases were observed among those aged 60–89. Nevertheless, new hospitalizations remained stable, and admissions to intensive care units as well as the number of deaths continued to decline. As of March 21, 83.1% of those aged 65 and older and 71.0% of residents in nursing homes or long-term care facilities had received a booster shot. Given the concurrent circulation of SARS-CoV-2 and influenza viruses, maintaining preventive measures remains recommended, particularly to protect vulnerable individuals: wearing masks in enclosed spaces or areas with high crowding, handwashing, and ventilating enclosed spaces. Vaccination efforts must now include the second booster dose for eligible populations, particularly those aged 80 and older, nursing home residents, and immunocompromised individuals. Similarly, adherence to other measures remains essential, particularly in the event of symptoms, a positive test result, or exposure to a high-risk contact.

Rise in incidence rate, nearly 90,000 new cases on average per day

Nationally, the incidence rate continued the rise that began the previous week (+36% in week 11). It stood at 937 cases per 100,000 inhabitants. While this rate increased across all age groups, the sharpest increases were observed among the oldest age group, with those aged 60–89 showing an increase of 45% or more. The incidence rate was, however, highest among those aged 6–14 and 30–49 (>1,000/100,000). The effective reproduction number (R_e) also increased (1.29) and remained above 1 for the second consecutive week. The testing rate also rose (+18%). The positivity rate followed the same trend, reaching 27.1% (+3.7 percentage points). The highest rates were observed among those aged 10–19 and 40–49, but it was the oldest age group (50–89) that showed the sharpest increases.

In mainland France, the incidence rate increased in all regions, ranging from +25% in Nouvelle-Aquitaine to +90% in Corsica. It exceeded 1,000 per 100,000 inhabitants in five regions and was once again highest in Brittany and the Grand Est. In the overseas territories, the incidence rate remained highest in Martinique (1,670) despite a sharp decline (-48%). Réunion (1,106, +6%) and Guadeloupe (961, -10%) also had high rates.

Continued stabilization of new hospitalizations and decline in critical care admissions

Nationally, the number of new hospital admissions remained stable, while new admissions to intensive care continued to decline (-13%), as did the number of deaths in hospitals and long-term care facilities. As for all-cause mortality, it returned to its usual fluctuation range for the third consecutive week.

In mainland France, the rate of new hospitalizations was stable or rising across the country, except in Occitanie, where it was declining (-21%). The rate of new admissions to intensive care was stable or declining in all regions, except in Normandy, where it was rising. In the overseas territories, the rate of new hospitalizations remained highest in Réunion, although it had decreased slightly. It was rising in French Guiana and stable in the other regions.

The BA.2 sublineage remains dominant, accounting for 73% of Omicron sequences

Sequencing data confirm the dominance of Omicron in France and the near-disappearance of Delta. Omicron accounted for 99.9% of interpretable sequences in the Flash S10 survey (03/07). The BA.2 sublineage of the Omicron variant is now predominant in France, accounting for 73% of the 2,229 Omicron sequences in the Flash S10 survey. The rise of BA.2 at the expense of BA.1 is observed throughout mainland France, but at varying levels across regions. In the overseas departments and regions (DROM), BA.2 also appears to be on the rise, but the data need to be consolidated. While it has been shown that BA.2 is more transmissible than BA.1, the two sublineages are similar in terms of immune evasion and disease severity.

Since February 18, 2022, the Delta/Omicron recombinant named XD has been subject to enhanced monitoring by the laboratories of the EMERGEN consortium, Santé publique France, and the CNR Virus des infections respiratoires. The majority of the XD variant’s genome corresponds to the Delta variant (AY.4 sublineage), but a large portion of the S gene (encoding the spike protein) corresponds to the Omicron variant (BA.1 sublineage). As of March 21, 44 sequences had been detected in France, including 21 during Flash surveys. These sequences correspond to cases from several regions dating back to early January 2022, suggesting that this recombinant has been circulating at low levels for several weeks. Furthermore, the detection rate of the XD variant during Flash surveys does not appear to have increased between S01 and S10. To date, very little data is available on the characteristics of the XD variant, but investigations are ongoing.

• More information is available in the variant risk analysis dated February 23, 2022.

More than 83% of those aged 65 and older have received a booster dose

As of March 21, 2022, the estimated vaccination coverage in the general population was 79.4% for a complete primary vaccination series and 58.5% for the booster dose. Vaccination coverage for the booster dose was 73.1% among those aged 18 and older and 83.1% among those aged 65 and older. In addition, 9.4% of children aged 10 to 11 had received a first dose of the vaccine (3.1% for those aged 5 to 9). 93.5% of residents in nursing homes or long-term care facilities had received a full primary vaccination series, and 71.0% had received a booster dose.

Following the latest recommendations regarding the second booster dose for people aged 80 and older as well as for residents in nursing homes or long-term care facilities, vaccination coverage data for the second booster dose will be published shortly.

In addition, Santé publique France is publishing an update on contact tracing activities.