COVID-19 goes away, flu returns: how the virus situation is changing in Luxembourg

The Ministry of Health and Social Protection has published the weekly summary of acute respiratory infections in Luxembourg for week 43 (20 to 26 October 2025). The summary covers the dynamics for COVID-19, seasonal influenza and respiratory syncytial virus (RSV).

The number of newly confirmed COVID-19 cases decreased from 244 to 155, a 36% decrease compared to the previous week. The decrease is also confirmed by the data on viral load in wastewater, which decreased, indicating an overall decrease in the circulation of the virus in the population.

According to the latest genomic sequencing results, the XFG variant (49.2%) and its sub-variant XFG.3 (33.5%) were dominant in September, indicating continued evolution of the virus but with no sign of a serious increase in threat.

Compared to the previous week, the number of laboratory-confirmed influenza cases increased from 19 to 31, indicating the beginning of the seasonal upswing. Influenza A was detected in 97 per cent of cases and influenza B in 3 per cent, which is a typical early season pattern.

So far we are talking about a slight increase, but further dynamics will depend on weather conditions and vaccination coverage.

Respiratory syncytial virus (RSV) cases also increased, from 10 to 22 in one week. Despite the increase, circulation levels remain low, especially compared to winter peaks, when the virus poses a serious threat to infants and the elderly.