The Development of Global Genomic Surveillance of Respiratory Syncytial Virus: Insights From 25 Project Countries, 2019-2023.

BACKGROUND

From 2016 to 2018, the World Health Organization (WHO) initiated a global RSV surveillance pilot program in 14 countries, expanding to 25 countries from 2019 to 2023. As part of this, a sequencing program was introduced to improve the understanding of RSV global genetic diversity prior to and following the introduction of interventions such as passive immunization, vaccines, and antivirals.

METHODOLOGY: All RSV sequence data submitted to GISAID by WHO project countries from January 1, 2019, to December 31, 2023, was analyzed to evaluate progress in sequencing, lineage distribution, and RSV fusion (F) protein diversity.

RESULTS

From 2019 to 2023, 44,571 RSV sequences were submitted to GISAID, including 61% RSV-A and 39% RSV-B, with 34% being whole-genome sequences. WHO project countries contributed 13,280 sequences (30%), with submissions increasing from 158 in 2020 to 3716 in 2023. Median data submission time improved from 1116 days in 2020 to 206 days in 2023. The dominant lineage detected was A.D.1 (20%) for RSV-A and B.D.4.1.1 (29%) for RSV-B. The F protein sequences showed high amino acid conservation: 97% for RSV-A and 96% for RSV-B.

CONCLUSION

Substantial progress has been made in RSV genomic sequencing capacities in WHO project countries as seen by the increased submissions and improved timeliness of sequence data. RSV exhibited co-circulating lineages (RSV-A and RSV-B) with low F protein diversity. It is important to sustain and further strengthen RSV sequencing capacities in all WHO regions as part of the ongoing WHO Global Genomic Surveillance strategy.