Fano Valeria, Coviello Enzo, Consonni Dario, Agresta Alessandro, Orsini Nicola, Crielesi Alessia, Miglietta Antonio Salvatore, Pasqua Caterina, Vairo Francesco, Vivaldi Fabio, De Angelis Giuseppe, Colaiocco Giovanni, Fabiani Massimo
Department of Public Health, Local Health Authority Asl Roma 2, Rome, Italy.
Medical Doctor, Bari, Italy.
Expert Rev Vaccines. 2022 Aug;21(8):1147-1157. doi: 10.1080/14760584.2022.2080057. Epub 2022 Jun 1.
The waning of the protective effect of COVID-19 vaccines and timing of booster doses are debated.
Population-based cohort study in the largest Health-Authority of Lazio region, Italy, on 946,156 residents aged 12+ (study period: 1 January 2021-10 January 2022). Vaccine effectiveness (VE) against any SARS-CoV-2 infection (symptomatic or asymptomatic) was estimated through multivariable negative-binomial models using unvaccinated person-time as a reference.
The primary vaccination cycle was completed by 81% of residents; of these, 45% received a booster dose. Vaccine coverages were lower for foreigners, and people living in deprived areas, families with children aged 0-11, and households size 1 or 6+. Overall, VE waned from 71% (95% Confidence Interval (CI) 70-73%) 1 month after the second dose to 43% (CI 41-45%) after 4 months and 24% (CI 21-27%) after 6 months, especially in the elderly aged 70+. We observed a prompt restore of VE 15-19 days after the booster dose (69%, CI 67-70%).
Our results support the recommendation of a booster dose 4 months after completion of the primary cycle, giving priority to elderly and fragile individuals. The lower vaccine coverage among social disadvantaged subgroups suggests the need of targeted communication and interventions.
新冠疫苗保护效果的减弱以及加强针的接种时间存在争议。
在意大利拉齐奥地区最大的卫生当局对946,156名12岁及以上居民进行基于人群的队列研究（研究期：2021年1月1日至2022年1月10日）。以未接种疫苗者的人时为参照，通过多变量负二项式模型估算针对任何SARS-CoV-2感染（有症状或无症状）的疫苗效力（VE）。
81%的居民完成了初级疫苗接种周期；其中45%接种了加强针。外国人、生活在贫困地区的人、有0至11岁儿童的家庭以及家庭规模为1人或6人及以上者的疫苗接种率较低。总体而言，疫苗效力在第二剂接种后1个月时为71%（95%置信区间[CI] 70 - 73%），4个月后降至43%（CI 41 - 45%），6个月后降至24%（CI 21 - 27%），在70岁及以上老年人中尤其如此。我们观察到加强针接种后15至19天疫苗效力迅速恢复（69%，CI 67 - 70%）。
我们的结果支持在初级周期完成后4个月接种加强针的建议，优先考虑老年人和脆弱个体。社会弱势群体亚组的疫苗接种率较低表明需要有针对性的宣传和干预措施。
