While originally, clinical trials suggested that the Johnson & Johnson Jensen COVID-19 vaccine was 85% effective in preventing serious diseases, clinical trial data released in January 2021 showed that the first After 4 weeks of dose administration, the single-shot vaccine was only 66.3% effective in preventing coronavirus infection.
Given that the original trials were conducted prior to the introduction of the delta variant, experts believe that although the vaccine is effective against newly emerging variants, the efficacy is low compared to protection against the original strain.
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However, with regard to the latest findings, J&J announced that the single-dose COVID vaccine was 79% protective against COVID-19 infections and 81% protective against COVID-19-related hospitalizations. Taking into account study data collected from March 1, 2020 to July 31, 2021, it was found that even after the delta variant came into existence, the vaccine’s effectiveness did not decrease over the study period. This indicated that the one-shot vaccine was still effective against the delta variant, which was called the version of concern by the World Health Organization (WHO).
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