Summary

As we enter the winter months of 2024/2025, nearly all EU and EEA nations are experiencing alarming spikes in respiratory infections, specifically influenza and respiratory syncytial virus (RSV). The latest data shows that the 10% test positivity threshold in primary care indicative of the influenza season has been surpassed, with multiple strains, including influenza A(H1N1)pdm09, A(H3N2), and B viruses, co-existing in the community.

This co-circulation of influenza and RSV, alongside the relatively low but persisting transmission of SARS-CoV-2, threatens to overwhelm healthcare services, particularly affecting young children and the elderly. Special attention is required as these groups face the highest risks of hospitalization, with RSV significantly impacting infants and older adults being particularly susceptible to severe influenza.

Public Health Recommendations

Given the expected surge in respiratory infections, it is vital for member states to bolster healthcare responses by enhancing infection prevention and control measures, especially in hospital settings and care facilities. Health authorities should also consider ramping up capacities in both primary and secondary care environments.

Vaccination remains the strongest defense against severe illness from respiratory viruses. Individuals eligible for vaccinations against influenza, COVID-19, or RSV, particularly those at higher risk of severe health outcomes, are urged to receive their vaccines promptly. Recent research also supports the use of immunoprophylaxis for infants at risk of RSV, as these interventions have proven both safe and effective in protecting vulnerable populations.

The updated COVID-19 booster vaccines set for winter 2024/2025 are believed to offer enhanced protection against the current SARS-CoV-2 variants. It is crucial for healthcare providers to consider early administration of antiviral medications for influenza and COVID-19 to mitigate the risk of severe disease among at-risk populations, especially if mismatched vaccine strains are circulating.

Current Epidemiological Trends in the EU/EEA

The European Respiratory Virus Surveillance Summary (ERVISS) highlights a troubling trend: hospital admissions related to RSV and influenza have risen significantly. Children aged 0-4 years, especially infants, have been hardest hit, with this group representing a staggering 83% of RSV-positive SARI admissions recorded between weeks 40-49 of 2024. In stark contrast, older adults exhibit the highest rates of influenza-related hospitalization.

The circulating strains of influenza this season suggest a diverse viral environment: currently, the proportion of influenza types A(H1N1)pdm09 and B appears prominent, while A(H3N2) remains a concern due to its potential mismatch with the vaccine formulations distributed in the northern hemisphere.

Addressing COVID-19 Variants

Currently monitored SARS-CoV-2 variants show a complex landscape, with KP.3 and the emerging recombinant variant XEC being noteworthy. While no variants are currently classified as variants of concern (VOC), vigilance in monitoring their prevalence and potential impact on clinical outcomes remains critical. Current data indicates no significant increase in hospitalizations due to these variants, but ongoing studies are required to assess their mutational advantage in evading vaccine-induced immunity.

Strengthening Public Health Measures

During this festive season, characterized by increased social gatherings and travel, the risk of respiratory virus transmission escalates. Health authorities should reinforce public health messaging, encouraging vaccination, respiratory hygiene, and the use of face masks in crowded settings to safeguard the most vulnerable.

Member states must prepare healthcare systems for a potential surge, ensuring adequate staffing and resources in emergency and intensive care units. Proactive measures in infection control will help mitigate outbreaks and protect both healthcare personnel and patients.

In conclusion, a concerted effort between health authorities, healthcare professionals, and the public is essential to navigate this challenging winter, with vigilance and preparedness as our best strategies against the rising tide of respiratory infections.