Bahrain Defense Force Hospital, National Task Force for Combating COVID-19, Riffa, Bahrain.
Division of Oncology, Department of Medicine, Columbia University, New York, USA.
Sci Rep. 2022 Jun 2;12(1):9236. doi: 10.1038/s41598-022-12543-4.
With the emergence of new SARS-Cov2 variants, critical questions have arisen about: (1) the effectiveness of the available COVID-19 vaccines developed to protect against the original Wuhan (wild type) variant and (2) the magnitude and clinical consequences of post-vaccination infections in the context of the Delta variant of SARS-Cov2. While some "real world" experiences with various vaccines have been reported, to our knowledge, few have examined comparative outcomes of various vaccines in one country as new SARS-CoV-2 variants have emerged. Here we present an analysis of COVID-19 related outcomes from a national database in Bahrain, a country with a total population of 1.51 million, where four vaccines were deployed (total vaccinated = 1,003,960 adults): AstraZeneca (AZ/Covishield), Pfizer/BioNtech, Sinopharm and Sputnik V. We compare the four vaccines, based on the following post-vaccination outcomes: SARS-CoV-2 infections, hospitalisations, ICU admissions and deaths, compared to unvaccinated individuals. We conclude that the four vaccines used in Bahrain were effective in significantly reducing all four COVID-19 related outcomes compared to unvaccinated individuals, prior to, and during the period when the Delta variant predominated in the country. However, compared to the three other vaccines, individuals vaccinated with Sinopharm vaccine had a higher risk of post-vaccination infections, hospitalisations and ICU admissions (e.g., 6.94%, 2.24%, 1.99% and 1.52% of COVID-19 cases of Sinopharm, Sputnik V, Pfizer and Covishield recipients, respectively, required hospitalisation versus 13.66% of COVID-19 cases among unvaccinated individuals); however, given the confounding factors, this needs to be confirmed by further studies. We find no evidence of biased selection for any vaccine, but note waning protection of the Pfizer/BioNtech vaccine during the January to June 2021 period in the age > 60 y cohort; however, this cannot be distinguished from the overall fall in hospitalisations overall. Our findings support the value of vaccination in preventing COVID-19 related outcomes, provide real world estimates on the outcomes and frequencies of post-vaccination infections for the four vaccines, which may inform vaccine selection in the context of the Delta variant across the globe.
随着新的 SARS-CoV2 变体的出现，人们提出了一些关键问题：(1) 为预防最初的武汉（野生型）变体而开发的现有 COVID-19 疫苗的有效性，以及 (2) 在 SARS-CoV2 的 Delta 变体背景下，接种疫苗后的感染的程度和临床后果。虽然已经报道了一些关于各种疫苗的“真实世界”经验，但据我们所知，当新的 SARS-CoV-2 变体出现时，很少有国家对各种疫苗的比较结果进行研究。在这里，我们分析了巴林的一个全国性数据库中与 COVID-19 相关的结果，该国总人口为 151 万，使用了四种疫苗（总共接种了 1003960 名成年人）：阿斯利康（AZ/Covishield）、辉瑞/生物技术、国药和 Sputnik V。我们根据以下接种疫苗后的结果对这四种疫苗进行了比较：与未接种疫苗的个体相比，SARS-CoV-2 感染、住院、入住 ICU 和死亡。我们得出的结论是，在 Delta 变体在该国占主导地位之前和期间，巴林使用的四种疫苗均能显著降低与未接种疫苗的个体相关的所有四种 COVID-19 相关结果。然而，与其他三种疫苗相比，接种国药疫苗的个体发生接种后感染、住院和入住 ICU 的风险更高（例如，接种国药、Sputnik V、辉瑞和 Covishield 的个体中 COVID-19 病例分别有 6.94%、2.24%、1.99%和 1.52%需要住院治疗，而未接种疫苗的个体中 COVID-19 病例有 13.66%）；然而，鉴于存在混杂因素，这需要进一步的研究来证实。我们没有发现任何对任何一种疫苗有偏见选择的证据，但注意到辉瑞/生物技术疫苗在 2021 年 1 月至 6 月期间对 60 岁以上人群的保护作用减弱；然而，这与总体住院人数下降无法区分。我们的研究结果支持疫苗接种在预防 COVID-19 相关结果方面的价值，为四种疫苗接种后的感染发生率和频率提供了真实世界的估计，这可能有助于在全球范围内针对 Delta 变体选择疫苗。
