Effect of Pfizer/BioNTech and Oxford/AstraZeneca vaccines against COVID-19 morbidity and mortality in real-world settings at countrywide vaccination campaign in Saudi Arabia.

ABSTRACT

OBJECTIVE: Vaccinations are highly essential to control infectious diseases and epidemics. Presently, the entire world faces a challenging crisis of "Severe Acute Respiratory Diseases Coronavirus 2 (SARS-CoV-2), also known as the COVID-19 pandemic". The impact of vaccines at national levels to reduce the SARS-CoV-2 cases and deaths are unclear, and people have concerns about the effectiveness of vaccines in real-world settings. This study's objective was to examine the effect of the "Pfizer/BioNTech and Oxford/AstraZeneca" vaccines to prevent SARS-CoV-2 cases and deaths in Saudi Arabia. MATERIALS AND METHODS: In this retrospective cohort study, we collected data on SARS-CoV-2 cases and deaths from the date of the first case of SARS-CoV-2 in Saudi Arabia March 2, 2020, to the date of launching the vaccination campaign on December 14, 2020; and from December 15, 2020, to September 8, 2021. We recorded the World Health Organization data and Ministry of Health of Saudi Arabia to evaluate the impact of the "Pfizer/BioNTech, (BNT162b2 mRNA) and Oxford/AstraZeneca (AZD1222)" vaccine against SARS-CoV-2 cases and deaths before and after the vaccination campaign in Saudi Arabia. RESULTS: Saudi Arabia launched the "Pfizer/BioNTech and Oxford/AstraZeneca" vaccination campaign against SARS-CoV-2 on December 14, 2020. In Saudi Arabia, before the vaccination campaign from March 2, 2020, to December 14, 2020, the mean daily SARS-CoV-2 cases were 1235.60, daily deaths were 22.70, that significantly reduced (p=0.0001) compared to the period after the vaccination campaign from December 15, 2020, to September 8, 2021, in which the daily cases fell to 692.08, and daily deaths fell to 9.48 (p=0.0001). CONCLUSIONS: In Saudi Arabia, Pfizer/BioNTech and Oxford/AstraZeneca vaccinations significantly reduced the number of SARS-CoV-2 cases and deaths after the vaccination compared to the period before the vaccination campaign at country levels. The study findings demonstrate that vaccination and adherence to nonpharmaceutical intervention can better control the COVID-19 pandemic.