Background: Human metapneumovirus (hMPV) circulates globally, yet its seasonal dynamics remain incompletely defined. Here, we describe the global timing, amplitude and duration of hMPV outbreaks, comparing the pre‐ versus post‐COVID‐19 periods. Methods: Surveillance data for hMPV were retrieved from WHO FluNet from Week 1/2016 until Week 26/2025. We examined the epidemic peak timing, amplitude and duration across seasons and latitudes and compared patterns in 2016–2019 with those in 2021–2025. Results: Over the study period, approximately 145,000 hMPV detections were reported to the WHO FluNet database from a total of 54 countries worldwide. Among the 15 countries with sufficient data to analyse seasonality, the epidemic timing aligned with geographic latitude, with the peak occurring in June–September in the Southern Hemisphere, February–April in the Northern Hemisphere, while the timing was variable across the intertropical belt. The amplitude of the peak varied across countries, with some countries characterized by single, well‐defined peaks and others with more widespread epidemics throughout the season. The median epidemic duration was 19.5 weeks (range 15–36). After the appearance of SARS‐CoV‐2, marked shifts in timing and amplitude were observed, with delays or dislocations in several countries compared with pre‐pandemic seasons. Conclusions: In this analysis of global surveillance data for hMPV (extended until June 2025), we highlighted latitudinal gradients in hMPV circulation, with disruptions associated with COVID‐19. Our findings emphasize the importance of sustained, type‐specific global surveillance to inform public health strategies and to characterize the post‐COVID‐19 global seasonality patterns of hMPV.

Background: Human adenoviruses (HAdV) circulate globally, but their seasonal patterns remain poorly defined. We aimed to characterize the timing, amplitude, and duration of HAdV epidemics worldwide and to compare patterns before and after the COVID‐19 pandemic. Methods: Virological surveillance data on HAdV were obtained from the WHO FluNet database: data from 65 countries were analyzed to estimate epidemic peak timing, amplitude, and duration across the Northern and Southern Hemispheres and the intertropical belt, comparing prepandemic (2016–2019) with postpandemic (2021–2024) periods. To ensure robustness, analyses were restricted to country‐seasons with ≥ 30 reporting weeks. Results: From 2016 to 2024, 65 countries reported roughly 148,000 HAdV detections across 335 country‐seasons; 46% of seasons had ≥ 50 detections. In the 20 countries with sufficient data for seasonality analyses, median epidemic duration was 31 weeks (range 5–42) and median peak amplitude 70% (40%–98%). Peak timing followed latitude: June–July in Southern Hemisphere, November–December in high‐latitude Northern countries, March–April in lower latitude. After COVID‐19, several countries showed marked timing shifts, with concurrent changes in amplitude. Conclusions: After the onset of the COVID‐19 pandemic, the usual seasonal patterns of HAdV were altered, with pronounced shifts in peak timing across settings and latitudes. These results underscore the need for strong, ongoing, type‐specific surveillance to guide public health strategies.

Background: Human rhinoviruses (HRVs) exhibit a global circulation characterized by prolonged epidemics and a less concentrated seasonal distribution compared with other respiratory viruses. In this study, we describe the timing, amplitude and duration of HRV epidemics on a global scale, analyzing seasonal patterns in relation to geographic latitude. Methods: HRV surveillance data reported to WHO FluNet from 2016 to 2025 were analyzed. Epidemic peak timing, amplitude and duration were estimated as a function of geographic latitude using harmonic analyses, with a comparison between the pre-pandemic (2016–2019) and post-pandemic (2021–2025) periods. Results: During the study period, 432,399 HRV detections were reported to WHO FluNet across 50 countries. Among these, 24 countries met the predefined criteria for seasonal analysis. Epidemic peak timing showed differences consistent with latitude, with peaks occurring in late autumn and winter in the Northern Hemisphere, during the central months of the year in the Southern Hemisphere, and greater temporal variability in the intertropical belt. Peak amplitude showed marked heterogeneity across countries (median 68.2%, range 28.1–96.7%), while epidemic duration indicated prolonged circulation (median 31 weeks, range 5–48 weeks). A secondary seasonal peak was identifiable in most countries, further supporting the relatively diffuse seasonal profile of HRV circulation. Comparison between the pre- and post-pandemic periods showed largely stable peak timing in most countries, alongside heterogeneous changes in peak amplitude. Conclusions: HRV is characterized by prolonged and weakly concentrated seasonal activity, with epidemic circulation often extending over several months. Despite major epidemiological perturbations during the COVID-19 pandemic, the timing of seasonal peaks remained largely stable across countries, highlighting the epidemiological resilience of HRV and the need for continuous, pathogen-specific surveillance.

Four years after the acute COVID-19 emergency, respiratory viruses circulate in overlapping seasonal patterns that repeatedly test surveillance systems and healthcare capacity