Harris Jeffrey E
Emeritus Professor, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge MA 02139, USA.
Physician, Eisner Health, Los Angeles CA 90015 USA.
Health Policy Technol. 2022 Jun;11(2):100583. doi: 10.1016/j.hlpt.2021.100583. Epub 2021 Nov 30.
We tested whether COVID-19 incidence and hospitalization rates during the Delta surge were inversely related to vaccination coverage among the 112 most populous counties in the United States, comprising 44 percent of the country's total population.
We measured vaccination coverage as the percent of the county population fully vaccinated as of July 15, 2021. We measured COVID-19 incidence as the number of confirmed cases per 100,000 population during the 14-day period ending August 12, 2021 and hospitalization rates as the number of confirmed COVID-19 admissions per 100,000 population during the same 14-day period.
In log-linear regression models, a 10-percentage-point increase in vaccination coverage was associated with a 28.3% decrease in COVID-19 incidence (95% confidence interval, 16.8 - 39.7%), a 44.9 percent decrease in the rate of COVID-19 hospitalization (95% CI, 28.8 - 61.0%), and a 16.6% decrease in COVID-19 hospitalizations per 100 cases (95% CI, 8.4 - 24.8%). Inclusion of demographic covariables, as well as county-specific diabetes prevalence, did not weaken the observed inverse relationship with vaccination coverage. A significant inverse relationship between vaccination coverage and COVID-19 deaths per 100,000 during August 20 - September 16 was also observed. The cumulative incidence of COVID-19 through June 30, 2021, a potential indicator of acquired immunity due to past infection, had no significant relation to subsequent case incidence or hospitalization rates in August.
Higher vaccination coverage was associated not only with significantly lower COVID-19 incidence during the Delta surge, but also significantly less severe cases of the disease.
We tested whether COVID-19 incidence and hospitalization rates during the Delta variant-related surge were inversely related to vaccination coverage among the 112 most populous counties in the United States, together comprising 44 percent of the country's total population. A 10-percentage-point increase in vaccination coverage was associated with a 28.3% decrease in COVID-19 incidence, a 44.9 percent decrease in the rate of COVID-19 hospitalization, and a 16.6% decrease in COVID-19 hospitalizations per 100 cases. Inclusion of demographic covariables, as well as county-specific diabetes prevalence, did not weaken the observed inverse relationship with vaccination coverage. A significant inverse relationship between vaccination coverage and COVID-19 deaths per 100,000 during August 20 - September 16 was also observed. Higher vaccination coverage was associated not only with significantly lower COVID-19 incidence during the Delta surge, but also significantly less severe cases of the disease.
我们测试了在美国112个人口最多的县（占全国总人口的44%）中，德尔塔毒株激增期间的新冠病毒感染率和住院率是否与疫苗接种覆盖率呈负相关。
我们将疫苗接种覆盖率衡量为截至2021年7月15日已完全接种疫苗的县人口百分比。我们将新冠病毒感染率衡量为在截至2021年8月12日的14天期间每10万人口中的确诊病例数，将住院率衡量为在同一14天期间每10万人口中的新冠病毒确诊住院人数。
在对数线性回归模型中，疫苗接种覆盖率每提高10个百分点，新冠病毒感染率下降28.3%（95%置信区间，16.8 - 39.7%），新冠病毒住院率下降44.9%（95%置信区间，28.8 - 61.0%），每100例新冠病毒住院病例数下降16.6%（95%置信区间，8.4 - 24.8%）。纳入人口统计学协变量以及各县特定的糖尿病患病率，并未削弱观察到的与疫苗接种覆盖率的负相关关系。在8月20日至9月16日期间，还观察到疫苗接种覆盖率与每10万人中的新冠病毒死亡数之间存在显著的负相关关系。2021年6月30日之前的新冠病毒累计感染率，这是过去感染所致获得性免疫的一个潜在指标，与8月份随后的病例发生率或住院率没有显著关系。
更高的疫苗接种覆盖率不仅与德尔塔毒株激增期间显著更低的新冠病毒感染率相关，而且与该疾病的严重程度显著降低相关。
我们测试了在美国112个人口最多的县（占全国总人口的44%）中，与德尔塔毒株相关的激增期间的新冠病毒感染率和住院率是否与疫苗接种覆盖率呈负相关。疫苗接种覆盖率每提高10个百分点，新冠病毒感染率下降28.3%，新冠病毒住院率下降44.9%，每100例新冠病毒住院病例数下降16.6%。纳入人口统计学协变量以及各县特定的糖尿病患病率，并未削弱观察到的与疫苗接种覆盖率的负相关关系。在8月20日至9月16日期间，还观察到疫苗接种覆盖率与每10万人中的新冠病毒死亡数之间存在显著的负相关关系。更高的疫苗接种覆盖率不仅与德尔塔毒株激增期间显著更低的新冠病毒感染率相关，而且与该疾病的严重程度显著降低相关。
