In week 12 (March 22–28, 2021), all epidemiological indicators, which were already at high levels, showed a marked increase. The incidence is rising across all age groups, particularly among children aged 0–14, where testing rates are increasing sharply. The deterioration of the health situation is observed in all metropolitan regions, and the strain on the hospital system, already very high, intensified in Week 12. Given the current dynamics of the epidemic (reproduction number of 1.18), this strain will increase in the coming days. New measures to reduce contact have been implemented; however, adherence to individual prevention measures, compliance with collective containment measures, and the acceleration of vaccination efforts are critical to addressing the high level of viral circulation and the heavy strain on hospitals.

37,000 new cases per day: the epidemic continues to spread

While indicators had already been rising since Week 10, the incidence increased by 22% in Week 12 (compared to Week 11), with 258,830 new confirmed cases—an average of nearly 37,000 cases per day. The incidence rate (386 per 100,000 inhabitants) and positivity rate (8.2%) were higher than in the previous week, as was the testing rate (4,698 per 100,000 inhabitants).

The trends observed last week are confirmed. The sharpest increase was observed among those aged 0–14 (+31%), against a backdrop of rising testing rates (+30%), partly due to campaigns organized in schools. It should be noted that during Week 12, the number of cases with a history of school attendance remains high, suggesting numerous infections among school-aged children and/or improved detection due to testing implemented in these settings.

After an improvement in indicators among those aged 75 and older, observed starting in week 05, the indicators have been rising for the past two weeks. For this age group, the incidence rate and the number of emergency department visits for suspected COVID-19 have been increasing since week 10, and the hospitalization rate has been increasing since week 11.

Hospital indicators continue to rise sharply

In hospitals, admissions of COVID-19 patients increased for the third consecutive week (+16% compared to Week 11). The increase in the admission rate to critical care units, observed since Week 8, continued in Week 12 (+13% compared to Week 11). As of March 30, 28,570 people were hospitalized (vs. 26,818 on March 23, a 7% increase), including 5,090 patients in critical care (vs. 4,655 on March 23, a 9% increase).

Three regions heavily affected, with the highest rates of hospitalizations and ICU admissions, which have risen this week:

• Ile-de-France, with the highest rates in mainland France at 29.8 per 100,000 (+18%) and 7.4 (+15%).

• Hauts-de-France, at 25.4 per 100,000 inhabitants (+4%) and 5.8 (+7%).

• Provence-Alpes-Côte d’Azur, at 26.7 per 100,000 inhabitants (+8%) and 5.3 (+11%).

The 20I/501Y.V1 (UK) variant was identified in 83% of the sequences generated during the Flash#5 survey

The Flash#5 survey, conducted on March 16, 2021, on SARS-CoV-2-positive samples by RT-PCR regardless of the screening result, included nearly 3,000 positive samples from 12 regions of metropolitan France. Among the 2,479 SARS-CoV-2-positive samples analyzed to date, the 20I/501Y.V1 variant was predominant (83% of interpretable sequences); the 20H/501Y.V2 and 20J/501Y.V3 variants were also detected but in smaller proportions (6.1% and 0.5%, respectively). Other lineages circulating in the country are also included in this genomic surveillance. These results will be confirmed in upcoming Flash surveys.

Meanwhile, on SI-DEP, at the national level, the following was observed in week 12:

• 79.9% corresponded to a suspected 20I/501Y.V1 (UK) variant

• 4.4% corresponded to suspected cases of the 20H/501Y.V2 (ZA) or 20J/501Y.V3 (BR) variants

The proportion of suspected cases of the 20I/501Y.V1 (UK) variant was over 80% (among screened positive tests) in 54 metropolitan departments and over 90% in 6 of them.

Other variants carrying mutations are likely to emerge in France in the future. Risk analyses used to characterize and classify them are now available on the Santé publique France website.

Prevention: Continue to follow safety measures even as vaccination progresses

Presented last week, the results of the CoviPrev survey (wave 22, March 15–17, 2021) show that while protective measures are widely used by the public, the systematic adoption of contact reduction is declining, likely reflecting public fatigue with control measures. In this context, given the high level of viral circulation and significant strain on the healthcare system, the rigorous application of all individual and collective measures is more essential than ever.
However, the intention to get vaccinated among those who have not yet done so has remained steady.

Vaccination:

• 8,284,391 people had received at least one dose of the COVID-19 vaccine as of March 30, 2021, and 2,778,546 people had received two doses, representing 12.3% and 4.1% of the population in France, respectively.

• 776,791 people under 65 with comorbidities had received at least one dose as of March 29, 2021, representing an estimated vaccination coverage of 23% in this population.

• 52.3% of all healthcare professionals have received at least one dose of the vaccine.

Vaccination appears to be accompanied by a relaxation of preventive measures, even though it is important to maintain them.

It remains essential that anyone with symptoms suggestive of COVID-19 immediately self-isolate and get tested as soon as possible. The use of digital tools (TousAntiCovid) is recommended to strengthen contact tracing and rapid isolation measures.