Impact of the COVID‐19 Pandemic on Influenza Circulation During the 2020/21 and 2021/22 Seasons, in Europe
Bibliographic record
Abstract
ABSTRACT Background The emergence of SARS‐CoV‐2 in late 2019 saw the implementation of public health and social measures (PHSM) by countries across Europe to reduce its transmission and impact on populations. Consequently, countries reported changes in influenza circulation and extensive disruptions to routine surveillance systems. Methods We describe the epidemiology of influenza in Europe between Weeks 40/2020 and 39/2022 compared to the 2016/17 to 2019/20 seasons, to assess the impact of the COVID‐19 pandemic and PHSM on surveillance systems and influenza circulation. Results Low detections of influenza were observed through primary care sentinel sources during seasonal influenza periods (Week 40 to 20); 56 (of 39,457 specimens tested; < 1% positivity) in 2020/21 and 7261 (of 64,153 specimens tested; 11% positivity) detections in 2021/22 were observed, compared to an average of 18,383 (of 50,544 specimens tested; 36% positivity) detections in 2016/17 to 2019/20. Similarly, 11 (of 19,989 specimens tested; < 1% positivity) and 1488 (of 23,636 specimens tested; 6% positivity) detections were reported through SARI surveillance sources in 2020/21 and 2021/22, respectively, compared to an average of 2850 (of 10,389 specimens tested; 27% positivity) detections in 2016/17 to 2019/20. However, the 2021/22 interseasonal period saw unusual increases in influenza detections across surveillance site types when PHSM were easing. Conclusion In conclusion, findings suggest that the restriction and easing of PHSM measures were associated with variations in influenza detections. Our observations of out‐of‐season influenza activity highlight the importance of an integrated respiratory surveillance strategy to monitor circulating respiratory viruses throughout the year to inform optimal prevention and control strategies.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".