Reduction in COVID-19 Patients Requiring Mechanical Ventilation Following Implementation of a National COVID-19 Vaccination Program — Israel, December 2020–February 2021

摘要

The availability of COVID-19 vaccines represents an opportunity to mitigate the effects of the global pandemic. Achieving high vaccination coverage through intensive vaccination campaigns has the potential to substantially reduce COVID-19–associated morbidity and mortality. Clinical trials have demonstrated the efficacy of COVID-19 vaccines in preventing mild and severe COVID-19 in a controlled setting. However, clinical trials are not designed to assess the population impact of vaccination in a real-world setting ( 1 , 2 ). Israel initiated a national vaccination campaign using the Pfizer-BioNTech BNT162b2 (Pfizer-BioNTech) vaccine in December 2020, prioritizing persons aged 60 years, health care workers, and persons with underlying medical conditions. By February 2021, 2-dose vaccination coverage among persons aged ≥70 years was 84%. To assess the effect of COVID-19 vaccination on the occurrence of severe disease, an ecological study was conducted. Requiring mechanical ventilation was used as a proxy for severe COVID-19. The number of COVID-19 patients aged ≥70 years (who had the highest 2-dose vaccination coverage, 84.3%) requiring mechanical ventilation was compared with that of patients aged 50 years, who had the lowest 2-dose vaccination coverage (9.9%). Since implementation of the second dose of the vaccination campaign, the ratio of COVID-19 patients requiring mechanical ventilation aged ≥70 years to those aged 50 years has declined 67%, from 5.8:1 during October–December 2020 to 1.9:1 in February 2021. These findings provide preliminary evidence of the effectiveness of vaccines in preventing severe cases of COVID-19 at the national level in Israel. Receipt of COVID-19 vaccines by eligible persons can help limit spread of disease and potentially reduce the occurrence of severe disease.