Three years after COVID, autumn flu brings back virus fears

The director of the European Centre for Disease Prevention and Control has called for heightened measures at the end of summer to prevent a resurgence of COVID-19 infection at the start of autumn.

In early September, increasing COVID-19 transmission had been reported by more than half of EU/EEA countries, said ECDC director Andrea Ammon.

The increases are likely contributed to by factors such as increased travel and large gatherings during the summer months, as well as waning immunity to infection following a long period of low virus circulation.

“Europe will soon see the arrival of autumn and winter, where we anticipate a resurgence of seasonal influenza and RSV (respiratory syncytial virus),” Ammon said. “We are also seeing small increases in SARS-CoV-2 (COVID-19) transmission in the EU/EEA and anticipate that all three viruses will co-circulate in the coming months. With this, there is the need to highlight the importance of vaccination and other public health measures to protect people’s health.”

Ammon said it was particularly important to keep a close eye on COVID-19 in older age groups. Out of 16 countries reporting data on age-specific case counts, nine have seen case numbers rise in people aged 80 and above, and 12 countries in people 65 years and above. These increases have lasted one to eight weeks up to 10 September 2023.

While COVID-19 deaths in absolute terms remain low compared to levels reported earlier in the pandemic, however, four out of 12 EU/EEA countries with age-specific death data have reported small, recent increases in deaths among people aged 65 years and above.

The coronavirus strain SARS-CoV-2 remains capable of acquiring mutations that can facilitate its continued circulation at unpredictable times throughout the year. The ECDC said the latest increases in SARS-CoV-2 transmission coincide with the emergence and dominance of the Omicron variants, which could lead to increased reinfections.

“For now, there is no indication that infection with these variants can cause more severe illness or make vaccines less effective against severe disease when compared to previously circulating variants,” Ammon said. “However, older people and those with underlying conditions are still at higher risk of severe outcomes if they get infected.”

In the last winter season, although COVID-19 circulated at much lower rates than in the previous two years, its impact was heightened by the co-circulation of influenza and RSV, resulting in healthcare services being put under heavy pressure.

“Despite uncertainties as to how the 2023/2024 season will evolve, we need to act now to minimise the expected burden on healthcare systems caused by co-circulation of respiratory viruses,” Ammon told European doctors.