Gabriele-Rivet Vanessa, Spence Kelsey L, Ogden Nicholas H, Fazil Aamir, Turgeon Patricia, Otten Ainsley, Waddell Lisa A, Ng Victoria
Public Health Risk Sciences Division, National Microbiology Laboratory, Infectious Disease Prevention and Control Branch, Public Health Agency of Canada, Guelph, Ontario and St-Hyacinthe, Québec, Canada.
Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
R Soc Open Sci. 2021 Nov 2;8(11):210834. doi: 10.1098/rsos.210834. eCollection 2021 Nov.
Public health measures applied exclusively within vulnerable populations have been suggested as an alternative to community-wide interventions to mitigate SARS-CoV-2 transmission. With the population demography and healthcare capacity of Canada as an example, a stochastic age-stratified agent-based model was used to explore the progression of the COVID-19 epidemic under three intervention scenarios (infection-preventing vaccination, illness-preventing vaccination and shielding) in individuals above three age thresholds (greater than or equal to 45, 55 and 65 years) while lifting shutdowns and physical distancing in the community. Compared with a scenario with sustained community-wide measures, all age-stratified intervention scenarios resulted in a substantial epidemic resurgence, with hospital and ICU bed usage exceeding healthcare capacities even at the lowest age threshold. Individuals under the age threshold were severely impacted by the implementation of all age-stratified interventions, with large numbers of avoidable deaths. Among all explored scenarios, shielding older individuals led to the most detrimental outcomes (hospitalizations, ICU admissions and mortality) for all ages, including the targeted population. This study suggests that, in the absence of community-wide measures, implementing interventions exclusively within vulnerable age groups could result in unmanageable levels of infections, with serious outcomes within the population. Caution is therefore warranted regarding early relaxation of community-wide restrictions.
有人建议，在脆弱人群中单独实施公共卫生措施，作为全社区干预措施的替代方案，以减轻严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的传播。以加拿大的人口统计学和医疗能力为例，使用了一个基于随机年龄分层的Agent模型，来探索在社区解除封锁和保持社交距离的情况下，针对三个年龄阈值（大于或等于45岁、55岁和65岁）以上的人群，在三种干预情景（预防感染疫苗接种、预防疾病疫苗接种和屏蔽）下2019冠状病毒病疫情的发展情况。与持续采取全社区措施的情景相比，所有年龄分层的干预情景都导致疫情大幅反弹，即使在最低年龄阈值下，医院和重症监护病房床位的使用也超过了医疗能力。年龄阈值以下的个体受到所有年龄分层干预措施实施的严重影响，出现大量可避免的死亡。在所有探索的情景中，对老年人进行屏蔽导致所有年龄段（包括目标人群）出现最不利的结果（住院、入住重症监护病房和死亡）。这项研究表明，在没有全社区措施的情况下，仅在脆弱年龄组内实施干预措施可能导致无法控制的感染水平，并在人群中产生严重后果。因此，对于过早放松全社区限制需要谨慎。
