AUTHOR=Tong Chengzhuo , Shi Wenzhong , Siu Gilman Kit-Hang , Zhang Anshu , Shi Zhicheng 

TITLE=Understanding spatiotemporal symptom onset risk of Omicron BA.1, BA.2 and hamster-related Delta AY.127

JOURNAL=Frontiers in Public Health

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.978052

DOI=10.3389/fpubh.2022.978052

ISSN=2296-2565

ABSTRACT=Purpose
Investigation of the community-level symptomatic onset risk regarding severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern, is crucial to the
pandemic control in the new normal.
Methods
Investigated in this study is the spatiotemporal symptom onset risk with Omicron BA.1,
BA.2, and hamster-related Delta AY.127 by a joint analysis of community-based
human mobility, virus genomes, and vaccinations in Hong Kong.
Results
The spatial spread of Omicron BA.2 was found to be 2.91 times and 2.56 times faster
than that of Omicron BA.1 and Delta AY.127. Identified has been an early spatial
invasion process in which spatiotemporal symptom onset risk was associated with
intercommunity and cross-community human mobility of a dominant source location,
especially regarding enhancement of the effects of the increased intrinsic
transmissibility of Omicron BA.2. Further explored is the spread of Omicron BA.1,
BA.2, and Delta AY.127 under different full and booster vaccination rate levels. An
increase in full vaccination rates has primarily contributed to the reduction in areas
within lower onset risk. An increase in the booster vaccination rate can promote a
reduction in those areas within higher onset risk.
Conclusions
As the study has provided a comprehensive investigation about the spatiotemporal
symptom onset risk of Omicron BA.1, BA.2, and hamster-related Delta AY.127, this
study can assist countries and regions to prevent the emergence of these variants on a
strategic basis. Moreover, this study provides scientifically derived findings on the
impact of the full and booster vaccination campaigns on reducing the symptomatic
infection.