PDF(Pubmed)
Abstract：
Little studies evaluated the effectiveness of booster vaccination of inactivated COVID-19 vaccines against being infected (susceptibility), infecting others (infectiousness), and spreading the disease from one to another (transmission). Therefore, we conducted a retrospective cohort study to evaluate the effectiveness of booster vaccination of inactivated COVID-19 vaccines against susceptibility, infectiousness, and transmission in Shenzhen during an Omicron BA.2 outbreak period from 1 February to 21 April 2022. The eligible individuals were classified as four sub-cohorts according to the inactivated COVID-19 vaccination status of both the close contacts and their index cases: group 2-2, fully vaccinated close contacts seeded by fully vaccinated index cases (reference group); group 2-3, booster-vaccinated close contacts seeded by fully vaccinated index cases; group 3-2, fully vaccinated close contacts seeded by booster-vaccinated index cases; and group 3-3, booster-vaccinated close contacts seeded by booster-vaccinated index cases. Univariate and multivariate logistic regression analyses were applied to estimate the effectiveness of booster vaccination. The sample sizes of groups 2-2, 2-3, 3-2, and 3-3 were 846, 1,115, 1,210, and 2,417, respectively. We found that booster vaccination had an effectiveness against infectiousness of 44.9% (95% CI: 19.7%, 62.2%) for the adults ≥ 18 years, 62.2% (95% CI: 32.0%, 78.9%) for the female close contacts, and 60.8% (95% CI: 38.5%, 75.1%) for the non-household close contacts. Moreover, booster vaccination had an effectiveness against transmission of 29.0% (95% CI: 3.2%, 47.9%) for the adults ≥ 18 years, 38.9% (95% CI: 3.3%, 61.3%) for the female close contacts, and 45.8% (95% CI: 22.1%, 62.3%) for the non-household close contacts. However, booster vaccination against susceptibility did not provide any protective effect. In summary, this study confirm that booster vaccination of the inactivated COVID-19 vaccines provides low level of protection and moderate level of protection against Omicron BA.2 transmission and infectiousness, respectively. However, booster vaccination does not provide any protection against Omicron BA.2 susceptibility.
摘要：
很少有研究评估灭活COVID-19疫苗加强疫苗对感染（易感性）的有效性，感染他人（传染性），并将疾病从一个传播到另一个（传播）。因此,我们进行了一项回顾性队列研究，以评估灭活COVID-19疫苗加强疫苗接种对易感性的有效性，传染性,并在2022年2月1日至4月21日的OmicronBA.2爆发期间在深圳传播。根据密切接触者及其指标病例的灭活COVID-19疫苗接种情况，将符合条件的个体分为四个亚组：第2-2组，完全接种疫苗的密切接触者，由完全接种疫苗的指标病例接种（参照组）；第2-3组，由完全接种疫苗的指标病例接种的加强疫苗的密切接触者；第3-2组，由加强疫苗的指标病例接种的加强疫苗的密切接触者接种。应用单变量和多变量逻辑回归分析来评估加强疫苗接种的有效性。第2-2、2-3、3-2和3-3组的样本量分别为846、1、115、1、210和2、417。我们发现，加强疫苗接种对传染性的有效性为44.9%(95%CI：19.7%，62.2%)对于≥18岁的成年人，62.2%（95%CI：32.0%，78.9%)为女性密切接触者，和60.8%（95%CI：38.5%，75.1%）为非家庭密切接触者。此外，加强疫苗接种对传播的有效性为29.0%(95%CI：3.2%，47.9％）对于≥18岁的成年人，38.9%（95%CI：3.3%，61.3%)女性密切接触者，和45.8%（95%CI：22.1%，62.3%）为非家庭密切接触者。然而,针对易感性的加强疫苗接种没有提供任何保护作用.总之,这项研究证实，灭活COVID-19疫苗的加强疫苗接种对OmicronBA.2传播和传染性提供了低水平的保护和中等水平的保护，分别。然而,加强疫苗接种不提供任何保护以防止OmicronBA.2易感性。
