On December 27, 62.4% of screening tests showed a profile consistent with Omicron. People aged 10–49 had the highest incidence rates (adjusted for the effect of the December 25 holiday) (>900 cases per 100,000 inhabitants), reaching 1,770 (+124%) among those aged 20–29. The incidence rate exceeded 1,000 cases per 100,000 inhabitants in Île-de-France, Provence-Alpes-Côte d’Azur, Corsica, and Auvergne-Rhône-Alpes. New hospitalizations were rising in these four regions and stable or declining in the rest of mainland France. As of December 28, 77.0% of the total population had received a full primary vaccination series. Among people aged 18 and older, 43.7% had received a booster dose (70.6% among those aged 65 and older).

During this season of festive gatherings, with high transmission levels and increasingly intense viral circulation dominated by the more transmissible Omicron variant, stepping up vaccination efforts—including booster shots as early as three months after the initial series—adherence to preventive measures, and full implementation of isolation protocols for cases and quarantine for contacts are essential to effectively curb the spread of the epidemic and protect the healthcare system.

More than 72,000 new cases per day on average and a rise in the effective reproduction number

Nationally, the incidence rate adjusted for the effect of the holiday (December 25) rose sharply in week 51 (+50%), reaching 833 cases per 100,000 inhabitants. On average, nearly 72,900 cases were diagnosed each day. The effective reproduction number was rising (1.22), indicating an acceleration in viral circulation. The adjusted incidence rate increased in all age groups, except for those aged 0–9, where it decreased (-9%). Incidence rates exceeded 900 cases per 100,000 population among those aged 10–49. The highest rates and the sharpest increases were observed among those aged 20–29 (+124%) and 30–39 (+62%). Across the entire population, the adjusted testing rate continued to rise (+17%). It stood at 15,666 (+46%) among those aged 20–29 but was declining among those under 20, in line with school holidays. The test positivity rate increased by 1.9 percentage points, reaching 8.7%.

In mainland France, the adjusted incidence rate was rising in all regions. It reached 1,409 (+108%) in Île-de-France, 1,092 (+20%) in Provence-Alpes-Côte d’Azur, 1,040 (+60%) in Corsica, and 1,000 (+36%) in Auvergne-Rhône-Alpes. In the overseas territories, the incidence rate remained high in Réunion (+15%) and was rising sharply in Guadeloupe (+220%) and Mayotte (+194%). It stood at 258 (+38%) in Martinique.

The Omicron variant is now the dominant strain in France

In week 51, the proportion of positive samples suspected of being linked to the Omicron variant (A0C0 coding after screening) increased significantly (39.4% vs. 9.3% in week 50). At the start of week 52 (Monday, December 27), it continued to rise, reaching 62.4%. Sequencing data finally indicated in week 50 an increasing circulation of the Omicron variant, identified in 15% of the 1,501 interpretable sequences from the December 13 Flash survey (unconsolidated data) vs. 1.5% in the previous week’s Flash survey. All of these indicators therefore suggest a sharp acceleration in the spread of Omicron. In week 51, the L452R mutation (carried mainly by the Delta variant) showed the opposite trend: it was detected in only 69.2% of screened positive samples (vs. 89.7% in week 50).

New hospitalizations and admissions to intensive care remain stable but at high levels

The number of new hospitalizations (7,621) and critical care admissions (1,719) (unconsolidated data) remained stable. As of December 28, 17,471 COVID-19 patients were hospitalized, including 3,429 in critical care. 1,143 deaths were reported in Week 51 (+8%), with 1,099 deaths in hospitals and 44 in long-term care facilities (unconsolidated data).

• In mainland France, rates of new hospitalizations were rising in Île-de-France, Provence-Alpes-Côte d’Azur, Corsica, and Auvergne-Rhône-Alpes. A slight increase in hospitalizations was also observed among those under 40, particularly among 20- to 29-year-olds and 0- to 9-year-olds.

• In the overseas territories, rates of new hospitalizations were rising in Réunion and French Guiana.

Nearly 88% of eligible people aged 65 and older have received their booster dose

On December 28, 2021, the estimated vaccination coverage in the general population based on Vaccin Covid was 77.0% for a complete primary vaccination series and 34.4% for the booster dose. Among those aged 12 and older, 89.6% had received a complete primary vaccination series. Among those aged 18 and older, 43.7% had received a booster dose, and 80.7% of those eligible for the booster as of that date had actually received it. Among those aged 65 and older, 70.6% had received a booster dose, and 87.9% of those eligible for the booster as of that date had received it.

As of December 28, 93.0% of residents in nursing homes or long-term care facilities had received a full primary vaccination series, and 66.5% had received a booster dose. Furthermore, the percentage of residents in nursing homes or long-term care facilities eligible for a booster shot on December 28, 2021, who had actually received it was 74.6% (vs. 73.9% on December 21, 2021). Furthermore, 76.2% of healthcare professionals working in nursing homes or long-term care facilities who were eligible for the booster dose had actually received it (vs. 71.7% on December 21, 2021). This percentage was 86.9% (vs. 84.5%) for self-employed healthcare professionals and 79.6% for salaried professionals (vs. 76.4%).