Directorate of Health Affairs, Monaco, Monaco.
Department of Mathematical Sciences, University of Liverpool, Liverpool, UK.
BMC Med. 2024 Jun 5;22(1):227. doi: 10.1186/s12916-024-03444-6.
We quantified SARS-CoV-2 dynamics in different community settings and the direct and indirect effect of the BNT162b2 mRNA vaccine in Monaco for different variants of concern (VOC).
Between July 2021 and September 2022, we prospectively investigated 20,443 contacts from 6320 index cases using data from the Monaco COVID-19 Public Health Programme. We calculated secondary attack rates (SARs) in households (n = 13,877), schools (n = 2508) and occupational (n = 6499) settings. We used binomial regression with a complementary log-log link function to measure adjusted hazard ratios (aHR) and vaccine effectiveness (aVE) for index cases to infect contacts and contacts to be infected in households.
In households, the SAR was 55% (95% CI 54-57) and 50% (48-51) among unvaccinated and vaccinated contacts, respectively. The SAR was 32% (28-36) and 12% (10-13) in workplaces, and 7% (6-9) and 6% (3-10) in schools, among unvaccinated and vaccinated contacts respectively. In household, the aHR was lower in contacts than in index cases (aHR 0.68 [0.55-0.83] and 0.93 [0.74-1.1] for delta; aHR 0.73 [0.66-0.81] and 0.89 [0.80-0.99] for omicron BA.1&2, respectively). Vaccination had no significant effect on either direct or indirect aVE for omicron BA.4&5. The direct aVE in contacts was 32% (17, 45) and 27% (19, 34), and for index cases the indirect aVE was 7% (- 17, 26) and 11% (1, 20) for delta and omicron BA.1&2, respectively. The greatest aVE was in contacts with a previous SARS-CoV-2 infection and a single vaccine dose during the omicron BA.1&2 period (45% [27, 59]), while the lowest were found in contacts with either three vaccine doses (aVE - 24% [- 63, 6]) or one single dose and a previous SARS-CoV-2 infection (aVE - 36% [- 198, 38]) during the omicron BA.4&5 period.
Protection conferred by the BNT162b2 mRNA vaccine against transmission and infection was low for delta and omicron BA.1&2, regardless of the number of vaccine doses and previous SARS-CoV-2 infection. There was no significant vaccine effect for omicron BA.4&5. Health authorities carrying out vaccination campaigns should bear in mind that the current generation of COVID-19 vaccines may not represent an effective tool in protecting individuals from either transmitting or acquiring SARS-CoV-2 infection.
我们定量评估了 2021 年 7 月至 2022 年 9 月期间不同社区环境中 SARS-CoV-2 的动态变化，以及摩纳哥不同关注变体（VOC）中 BNT162b2 mRNA 疫苗对接触者的直接和间接影响。
通过摩纳哥 COVID-19 公共卫生计划的数据，我们前瞻性调查了 6320 名索引病例的 20443 名接触者。我们计算了家庭（n=13877）、学校（n=2508）和职业（n=6499）环境中的二次攻击率（SAR）。我们使用二项回归和互补对数-对数链接函数来测量索引病例感染接触者和接触者感染的调整后的危险比（aHR）和疫苗有效性（aVE）。
在家庭中，未接种疫苗和接种疫苗的接触者的 SAR 分别为 55%（95%CI 54-57）和 50%（48-51）。在工作场所中，SAR 分别为 32%（28-36）和 12%（10-13），在学校中，SAR 分别为 7%（6-9）和 6%（3-10）。在家庭中，接触者的 aHR 低于索引病例（delta 的 aHR 为 0.68 [0.55-0.83] 和 0.93 [0.74-1.1]；omicron BA.1&2 的 aHR 为 0.73 [0.66-0.81] 和 0.89 [0.80-0.99]）。疫苗接种对 omicron BA.4&5 的直接或间接 aVE 均无显著影响。接触者的直接 aVE 为 32%（17，45）和 27%（19，34），而索引病例的间接 aVE 分别为 delta 的 7%（-17，26）和 omicron BA.1&2 的 11%（1，20）。在 omicron BA.1&2 期间，具有先前 SARS-CoV-2 感染和单次疫苗接种的接触者的 aVE 最大（45%[27，59]），而在 omicron BA.4&5 期间，具有三种疫苗接种剂量（aVE-24%[-63，6]）或单次接种和先前 SARS-CoV-2 感染（aVE-36%[-198，38]）的接触者的 aVE 最小。
无论接种疫苗的次数和先前的 SARS-CoV-2 感染情况如何，BNT162b2 mRNA 疫苗对 delta 和 omicron BA.1&2 的传播和感染的保护作用都很低。对于 omicron BA.4&5，疫苗没有显著效果。开展疫苗接种运动的卫生当局应铭记，当前一代的 COVID-19 疫苗可能不是保护个人免受 SARS-CoV-2 感染的有效工具。
