In week 50 (December 13–19, 2021), the incidence of COVID-19 across the country remained at a very high level. Although the increase was less pronounced than in previous weeks at the national level, sharp rises in incidence were observed in several regions. Furthermore, incidence rates continued to rise among young adults and remained high among children. Finally, the rapid acceleration in the spread of the Omicron variant—whose higher transmissibility has now been demonstrated—calls for the utmost vigilance, particularly in the context of year-end holiday gatherings. Between December 20 and 22, 30% of screening tests showed a profile consistent with the presence of the Omicron variant, and as of December 23, 1,440 cases had been confirmed as Omicron through sequencing across all metropolitan regions, as well as in Réunion, Guadeloupe, Saint Martin, and French Guiana. New hospitalizations and admissions to intensive care appeared to be stabilizing at a high level, but remained lower to date than during the first three waves. As of December 21, 76.8% of the total population had received a full primary vaccination series. Among people aged 18 and older, 39.0% had received a booster dose (and 68.1% among those aged 65 and older). As the holidays approach, strict adherence to all preventive measures—including reducing contact and frequently ventilating enclosed spaces—is more necessary than ever. With the Omicron variant expected to dominate the epidemic in the very short term, vaccination—including booster shots—combined with preventive measures and contact tracing remain essential to effectively curb the spread of infections and protect the healthcare system.

Over 50,000 new cases on average per day

Nationally, the incidence rate rose by 8%, reaching 550 cases per 100,000 inhabitants in week 50. On average, more than 50,000 cases were diagnosed each day. The effective reproduction number remained significantly above 1, indicating a continued increase in viral circulation. The incidence rate stabilized among those aged 60 and older, while it continued to rise at a high level among younger age groups, particularly those aged 20–29 (+42%) and 30–39 (+14%), reaching 836 in this age group. Among children, the incidence rate decreased among those aged 0–9 (-9%), as did the testing rate (-14%). Across the entire population, the testing rate continued to rise (+6%). The test positivity rate remained high at 6.8% (+0.2 percentage points).

In mainland France, the incidence rate was highest and still rising in Provence-Alpes-Côte d’Azur (+17%), followed by Auvergne-Rhône-Alpes (+7%) and Île-de-France (+33%), where it increased by +51% in Paris. In the overseas territories, the incidence rate continued to rise in Réunion and stabilized in Martinique.

Hospitalizations, particularly in intensive care, remain at high levels

As of December 21, 16,142 COVID-19 patients were hospitalized, including 3,109 in intensive care. More than 1,000 deaths were reported (+8%), including 969 in hospitals and 34 in long-term care facilities during week 50 (unconsolidated data). In addition, excess all-cause mortality was recorded between weeks 47 and 49, particularly in Auvergne-Rhône-Alpes and Provence-Alpes-Côte d’Azur.

In mainland France, rates of new hospitalizations and admissions to intensive care stabilized in most regions and age groups, except in Corsica and Auvergne-Rhône-Alpes. In the overseas territories, incidence rates and new hospitalizations continued to rise in Réunion, while these indicators stabilized in Martinique.

Spread of the Omicron variant in France

The screening strategy implemented in France aims to track mutations that may impact the virus’s characteristics. Since June 2021, the E484K, E484Q, and L452R mutations have been targeted (see Risk Analysis of 06/02/21) (ABC coding). However, since the emergence of the Omicron variant, which carries none of these mutations, enhanced monitoring of screening results has been implemented to identify samples suggesting its presence (profile coded A0B0C0). However, this monitoring is not perfectly specific to Omicron, as other variants have the same screening profile (e.g., B.1.640). This is why a new code (D) was recently added to collect results from additional screening tests targeting several mutations specific to Omicron.

In week 50, the L452R mutation (primarily carried by the Delta variant) was detected in 89.5% of screened positive samples (vs. 97.2% in week 49). At the same time, the proportion of A0B0C0 samples increased significantly (10.6% vs. 2.8% in week 49), with regional variations. In week 50, 980 results indicated the presence of one of the Omicron target mutations (D1), representing 9% of interpretable results (vs. 1% in week 49). At the start of week 51 (December 20–22 inclusive), the proportion of D1 was 32% (1,568 D1 out of 4,904 interpretable results). However, testing for mutations included in D is not yet widespread, and these results should therefore be interpreted with caution. Nevertheless, all indicators suggest a sharp acceleration in the spread of Omicron. As for sequencing data, they indicate that the Delta variant remains the predominant variant in circulation, identified in 99% of interpretable sequences in France during the Flash S48 survey and 97% during the Flash S49 survey. However, a downward trend in the proportion of Delta is confirmed by these same data.

Nearly 87% of eligible individuals aged 65 and older have received their booster dose

On December 21, 2021, the estimated vaccination coverage in the general population based on Vaccin Covid was 76.8% for a complete primary vaccination series and 30.7% for the booster dose. Among those aged 18 and older, 39.0% had received a booster dose, and 79.4% of those eligible for the booster as of that date had actually received it. Among those aged 65 and older, 68.1% had received a booster dose, and 86.9% of those eligible for the booster as of that date had actually received it.

As of December 21, 92.9% of residents in nursing homes or long-term care facilities had received a complete primary vaccination series, and 65.5% 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 21, 2021, who had actually received it was 73.9% (vs. 72.4% on December 14, 2021). Vaccination coverage for the booster dose was 39.8% (vs. 28.4% on December 14) for healthcare professionals working in nursing homes or long-term care facilities, 65.2% (vs. 57.0%) for private practitioners, and 41.0% for salaried healthcare professionals in healthcare facilities (vs. 31.6%). Furthermore, 71.7% of healthcare professionals working in nursing homes or long-term care facilities who were eligible for the booster dose had actually received it (vs. 54.6% on December 14, 2021). This percentage is 84.5% (vs. 76.3%) for self-employed healthcare professionals and 76.4% for salaried professionals (vs. 64.4%).

• Learn more - Update on: What is the COVID-19 vaccination coverage among healthcare professionals and residents in long-term care facilities?

The mental health of the French population remains poor

During wave 30 of the CoviPrev survey (November 30–December 7), mental health indicators (depressive and anxious states, sleep problems, and suicidal thoughts) remained stable compared to the previous waves of the survey, but at a high and concerning level. Nearly one-third of respondents exhibited an anxious or depressive state.

The health crisis has had a lasting and significant impact on the population’s mental health. If you notice signs of depression (sadness, loss of interest, loss of energy) or anxiety (tension, irritability), it is important to seek information and talk about it so you can receive guidance on available support and solutions. Don’t hesitate to consult your doctor, call 0 800 130 00 to be referred to a listening service or psychological support, or visit the Psycom.org website for more information.

• Learn more - Update: How is the mental health of the French population evolving during the Covid-19 pandemic?