In week 17 (April 25–May 1, 2022), the slowdown in the SARS-CoV-2 epidemic was confirmed across the country, with a decrease in incidence rates (-39%) and positivity rates (-5.0 percentage points). This trend was observed in all metropolitan regions and all age groups. Nevertheless, these indicators remained high: the incidence rate still far exceeded 500 per 100,000 in most age groups, and the positivity rate reached 23.5%. The decline observed in week 16 in the number of new hospitalizations was confirmed (-15% after consolidation) and appeared to continue this week. In the overseas territories, while incidence and the rate of new hospital admissions remained high in Réunion, they nevertheless decreased in week 17. As of May 2, 3.9% of those aged 60–79 and 15.1% of those aged 80 and older had received a second booster dose. As SARS-CoV-2 and influenza viruses continue to circulate, it remains essential to continue implementing preventive measures to maintain the favorable epidemic trend and protect vulnerable individuals. In addition, vaccination efforts must continue, particularly regarding the second booster dose for eligible individuals, especially the elderly and those with compromised immune systems. Adherence to other recommended measures also remains necessary in the event of symptoms, a positive test result, or exposure to a confirmed case.

Sharp Decline in Incidence Rate

Nationally, the incidence rate fell sharply and approached the threshold of 500 cases per 100,000 inhabitants (547, -39% compared to Week 16). This decline was observed across all age groups and exceeded 40% this week among those aged 20–49. Nevertheless, this indicator exceeded 600 per 100,000 in most age groups. It remained lowest among those under 20: 247 (-31%) among 0-9-year-olds and 301 (-38%) among 10-19-year-olds. Conversely, the highest incidence rates were observed among those aged 70–79 (732, -37%) and those aged 90 and older (721, -38%). The testing rate followed the same trend in week 17 (2,330 per 100,000, -26%). The sharpest declines were once again observed among those under 20, with a rate of 1,308 (-30%) among 0-9-year-olds and 1,601 (-35%) among 10-19-year-olds. It remained above 3,000 per 100,000 only among those aged 90 and older (3,587, -25%). As for the positivity rate, it continued to decline for the second consecutive week, falling by 5 percentage points nationwide. It remained high, however (23.5%), representing nearly one in four positive tests. Similarly, while it decreased across all age groups, the decline was significantly less pronounced among those aged 0–19. The sharpest declines were observed among those aged 30–39 and 50–79. This indicator remained above 25% among those aged 40–79.

In mainland France, the incidence rate fell sharply across the entire country. The highest rates were observed in Corsica and Brittany (>600), and the lowest in Île-de-France and Nouvelle-Aquitaine, where it fell below the threshold of 500 per 100,000. The testing rate, which was declining in all regions, remained highest in Corsica (>3,000). The positivity rate decreased markedly across the entire country. It was below 20% in Île-de-France but still exceeded 30% in four regions, notably in Brittany. In the overseas territories, although a decline in viral circulation appeared to be beginning in Réunion, the incidence rate there remained high (1,300). It still exceeded 500 per 100,000 in Guadeloupe and Martinique.

Decline in the number of new hospitalizations

Nationally, the number of new hospitalizations was 6,288 (-29%) and the number of new admissions to intensive care was 668 (-28%). The extent of these declines will be confirmed in the next Epidemiological Update. The previous week, after consolidation, these indicators already showed a decrease, particularly in hospitalizations (8,844, -15%), but also in critical care admissions, although the decline was less pronounced (922, -8%). In Week 17, the number of deaths in hospitals and long-term care facilities stood at 714 (-19%, data also unconsolidated). The moderate excess mortality from all causes observed between Weeks 12 and 16 primarily affected those aged 65–84 and those aged 85 and older.

In mainland France, rates of new hospitalizations were again highest in Bourgogne-Franche-Comté and Normandy. Rates of new admissions to intensive care remained stable in
Corsica and Bourgogne-Franche-Comté and decreased in the other regions. In the overseas territories, the rate of new hospitalizations remained highest in Réunion.

The BA.2 sublineage of the Omicron variant remains dominant

Sequencing data confirm the ubiquity of Omicron in France. In mainland France, it accounted for more than 99.9% of interpretable sequences in the Flash S16 survey (04/19) and 100% in the Flash S15 survey (04/11). In the overseas departments and regions (DROM), Omicron has been the only variant detected since Flash S06-2022 (02/07). These data illustrate the near-exclusive circulation of Omicron throughout the country. The BA.2 sublineage is predominant in France, accounting for 99% of sequences in the Flash S16 survey (04/19). The Omicron sublineages BA.4 and BA.5 are subject to enhanced surveillance. They circulate primarily in South Africa, where characterization studies are underway. As of May 2, 2022, two cases of BA.4 and six cases of BA.5 have been confirmed in France and are under investigation.

The XD recombinant has been classified as a variant under monitoring (VUM) since the variant risk assessment of March 23, 2022, due to its genetic characteristics derived from the parent variants of concern (VOCs) (Delta AY.4 and Omicron BA.1). It accounts for less than 0.1% of interpretable sequences from Flash surveys S01 (01/03) through S16 (04/19).

• More information is available in the variant risk analysis dated April 20, 2022.

More than 15% of those aged 80 and older have received a second booster dose

As of May 2, 2022, the estimated vaccination coverage in the general population was 79.6% for a complete primary vaccination series and 59.1% for the booster dose. Vaccination coverage for the booster dose was 73.8% among those aged 18 and older and 83.8% among those aged 65 and older. In addition, 9.6% of children aged 10 to 11 had received a first vaccine dose (3.2% for those aged 5 to 9). Among those aged 60–79, 3.9% had received a second booster dose (3.3% as of April 25, 2022), and 34.1% of those eligible had actually received it. Among those aged 80 and older, vaccination coverage for the second booster dose was 15.1% (13.2% as of April 18, 2022), and 22.3% of those eligible as of that date had received it.

Data on vaccination coverage by department, as well as data on the second booster dose among those aged 60 and older and among residents of nursing homes (Ehpad) or long-term care facilities (USLD), are published on Géodes.