Directorate of Research, Studies and Documentation, National Public Health Organization, Athens, Greece.
Pathophysiology Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
J Hosp Infect. 2023 Feb;132:46-51. doi: 10.1016/j.jhin.2022.11.016. Epub 2022 Dec 5.
To estimate the incidence, timing and severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) breakthrough infections in fully vaccinated healthcare personnel (HCP).
In total, 6496 fully vaccinated HCP were analysed prospectively from 15 November 2021 to 17 April 2022. Full coronavirus disease 2019 (COVID-19) vaccination was defined as a complete primary vaccination series followed by a booster dose at least 6 months later.
Overall, 1845 SARS-CoV-2 breakthrough infections occurred (28.4 episodes per 100 HCP), of which 1493 (80.9%) were COVID-19 cases and 352 (19.1%) were asymptomatic infections. Of the 1493 HCP with COVID-19, four were hospitalized for 3-6 days (hospitalization rate among HCP with COVID-19: 0.3%). No intubations or deaths occurred. SARS-CoV-2 breakthrough infections occurred at a mean of 16.2 weeks after the last vaccine dose. Multi-variable regression analyses showed that among the 1845 HCP with a breakthrough infection, the administration of a COVID-19 vaccine dose ≥16.2 weeks before the infection was associated with increased likelihood of developing COVID-19 rather than asymptomatic SARS-CoV-2 infection [odds ratio (OR) 1.58, 95% confidence interval (CI) 1.01-2.46; P=0.045] compared with administering a vaccine dose later. The likelihood of developing COVID-19 compared with asymptomatic infection increased by 7% weekly after the last COVID-19 vaccine dose (OR 1.07, 95% CI 1.03-1.11; P=0.001).
SARS-CoV-2 breakthrough infections are common among fully (boosted) vaccinated HCP. However, full COVID-19 vaccination offered considerable protection against hospitalization. These findings may contribute to defining the optimal timing for booster vaccinations. More efficient COVID-19 vaccines that will also confer protection against SARS-CoV-2 infection are needed urgently.
估计完全接种疫苗的医护人员（HCP）中严重急性呼吸综合征冠状病毒 2 型（SARS-CoV-2）突破性感染的发生率、时间和严重程度。
总计前瞻性分析了 2021 年 11 月 15 日至 2022 年 4 月 17 日期间的 6496 例完全接种疫苗的 HCP。全面的 2019 年冠状病毒病（COVID-19）疫苗接种定义为完整的初级疫苗接种系列，随后至少 6 个月后进行加强针接种。
总体而言，发生了 1845 例 SARS-CoV-2 突破性感染（每 100 名 HCP 中发生 28.4 例），其中 1493 例（80.9%）为 COVID-19 病例，352 例（19.1%）为无症状感染。在 1493 例 COVID-19 的 HCP 中，有 4 例住院治疗 3-6 天（COVID-19 住院率：0.3%）。没有插管或死亡发生。SARS-CoV-2 突破性感染发生在最后一剂疫苗后平均 16.2 周。多变量回归分析显示，在 1845 例突破性感染的 HCP 中，感染前≥16.2 周接种 COVID-19 疫苗与发生 COVID-19 而非无症状 SARS-CoV-2 感染的可能性增加相关[比值比（OR）1.58，95%置信区间（CI）1.01-2.46；P=0.045]，而不是接种较晚的疫苗。与无症状感染相比，最后一剂 COVID-19 疫苗后每周 COVID-19 发病的可能性增加 7%（OR 1.07，95%CI 1.03-1.11；P=0.001）。
SARS-CoV-2 突破性感染在完全（加强）接种疫苗的 HCP 中很常见。然而，全面的 COVID-19 疫苗接种为住院提供了相当大的保护。这些发现可能有助于确定加强针接种的最佳时机。急需更有效的 COVID-19 疫苗，这些疫苗还能预防 SARS-CoV-2 感染。
