Introducing seasonal influenza vaccine in Bhutan: Country experience and achievements

Seasonal influenza surveillance and vaccination policies in the WHO South-East Asian Region

The WHO South-East Asia Region (SEAR), with its high population density, is recognised by epidemiologists as a critical reservoir for the emergence and global dissemination of novel influenza strains, making it a potential epicentre for future influenza pandemics. Despite this significant risk, most SEAR countries lack comprehensive seasonal influenza vaccination policies, resulting in low vaccine uptake across the region. This review analysed the latest WHO National Influenza Programme factsheets from the 11 SEAR member states and supplemented this with extensive manual literature searches using electronic databases and government websites. As of October 2022, only three countries-India, Bhutan and Thailand-had established seasonal influenza vaccination policies. Among them, Bhutan and Thailand have policies that cover all five WHO-recommended high-risk groups. While national influenza surveillance systems are in place across SEAR, only India and the Democratic People's Republic of Korea claim full population coverage. Influenza vaccine production capacity is limited to Bangladesh, India and Indonesia. The region's varied climatic conditions and insufficient local data have further obscured the true burden of influenza. Thailand offers a successful model for other countries in the region, beginning with the most vulnerable groups and gradually expanding coverage. To effectively develop and implement national influenza vaccination policies, SEAR countries must close the evidence gap by strengthening surveillance systems to provide accurate, timely data and prioritise context-specific research, leverage existing vaccine infrastructure, enhance public education and finally engage with local and international stakeholders to establish strong international cooperation to support these efforts and improve pandemic preparedness.

Heterogeneity of influenza infection at precise scale in Yinchuan, Northwest China, 2012-2022: evidence from Joinpoint regression and spatiotemporal analysis

Identifying high-risk regions and turning points of influenza with a precise spatiotemporal scale may provide effective prevention strategies. In this study, epidemiological characteristics and spatiotemporal clustering analysis at the township level were performed. A descriptive study and a Joinpoint regression analysis were used to explore the epidemiological characteristics and the time trend of influenza. Spatiotemporal autocorrelation and clustering analyses were carried out to explore the spatiotemporal distribution characteristics and aggregation. Furthermore, the hotspot regions were analyzed by spatiotemporal scan analysis. A total of 4025 influenza cases were reported in Yinchuan showing an overall increasing trend. The tendency of influenza in Yinchuan consisted of three stages: increased from 2012 to the first peak in 2019 (32.62/100,000) with a slight decrease in 2016; during 2019 and 2020, the trend was downwards; then it increased sharply again and reached another peak in 2022. The Joinpoint regression analysis found that there were three turning points from January 2012 to December 2022, namely January 2020, April 2020, and February 2022. The children under ten displayed an upward trend and were statistically significant. The trend surface analysis indicated that there was a shifting trend from northern to central and southern. A significant positive spatial auto-correlation was observed at the township level and four high-incidence clusters of influenza were detected. These results suggested that children under 10 years old deserve more attention and the spatiotemporal distribution of high-risk regions of influenza in Yinchuan varies every year at the township level. Thus, more monitoring and resource allocation should be prone to the four high-incidence clusters, which may benefit the public health authorities to carry out the vaccination and health promotion timely.