Solna, 18 December 2024
“As we enter the festive season, respiratory virus transmission is expected to rise further following recent sharp increases. Simple measures like good respiratory hygiene, ventilation, and staying home when unwell can help reduce transmission. We encourage eligible individuals to get immunised without delay against respiratory viruses. In this way, we can protect ourselves and loved ones, reduce strain on health systems and ensure healthy celebrations.” – Edoardo Colzani, Head of Section for Respiratory Viruses at the European Centre for Disease Prevention and Control (ECDC).
Epidemiological context
- Almost all countries reporting data to ECDC are observing sharp increases in indicators of both influenza and respiratory syncytial virus (RSV) activity, with a visible impact in secondary care. The EU/EEA 10% primary care test positivity threshold signalling the start of the influenza season has been reached, with influenza A(H1N1)pdm09, A(H3N2) and B viruses co-circulating.
- Co-circulation of influenza viruses and RSV against the current background of continued relatively low-level transmission of SARS-CoV-2 could substantially impact healthcare services. Hospital admissions could occur in all age groups, with very young children (due to RSV) and older adults particularly affected. The impact of influenza may be worse if an A(H3N2) subclade that is less well matched with the northern hemisphere vaccine dominates.
- The end-of-year festive season is traditionally associated with activities such as social gatherings, shopping and travelling, which pose additional risks for intensified respiratory virus transmission.
Recommendations
- Member States should be prepared for continued increases in influenza and RSV activity during the coming weeks, and consider infection prevention and control practices to reduce transmission in healthcare settings, including long-term care facilities. They should also consider increasing primary and secondary healthcare system capacity.
- Immunisation is the most effective measure to protect against severe viral respiratory disease caused by certain viruses and scenario modelling has shown high vaccine uptake at the population level is strongly correlated with reduced disease burden.
- People eligible for vaccination against influenza, COVID-19 or RSV, particularly those at higher risk of severe outcomes, are encouraged to get vaccinated without delay in line with national recommendations to have the best chance of being protected.
- RSV immunoprophylaxis for infants, which have been shown to be safe and effective, can be considered per national guidelines.
- The updated COVID-19 vaccines offered as a booster for winter 2024-2025 should provide improved protection against severe outcomes from the currently circulating SARS-CoV-2 variants compared to the XBB.1.5-targeting COVID-19 vaccine booster offered in autumn 2023.
- Clinicians should be reminded that, when indicated in national guidelines, the early use of antiviral treatments for influenza and COVID-19 may prevent progression to severe disease in vulnerable groups.
- For influenza, it may be prudent to have a lower threshold for antiviral use in risk groups, if an influenza virus subclade not well matched with the northern hemisphere vaccine dominates.
- SARS-CoV-2 monoclonal antibodies currently authorised in the EU/EEA lack efficacy against variants carrying the F456L mutation, which is widely present in currently circulating XEC, KP.3 and BA.2.86 lineages. However, available antiviral treatments are expected to remain effective.
- People eligible for vaccination against influenza, COVID-19 or RSV, particularly those at higher risk of severe outcomes, are encouraged to get vaccinated without delay in line with national recommendations to have the best chance of being protected.
- Unusual events or clusters of respiratory infections, for example adenovirus or Mycoplasma pneumoniae, not monitored by routine surveillance but placing additional strain on healthcare systems, should be reported through EpiPulse. Additionally, clusters of atypical or particularly severe presentations for influenza (or suspected zoonotic avian influenza), RSV and SARS-CoV-2 should also be reported.
Source – ECDC: www.ecdc.europa.eu