“Effectiveness of COVID-19 Vaccines in preventing Infectiousness, Hospitalization and Mortality: A Historical Cohort Study Using Iranian Registration Data During Vaccination program”

Abstract

Background: There are some concerns about the effectiveness of the inactivated and vector-based vaccines against SARS-CoV-2 in the real-world settings with the emergence of new mutations, especially variants of concern. Data derived from administrative repositories during mass-vaccination campaigns or programs are of interest to study vaccine effectiveness (VE). Methods: Using 4-repository administrative data linkage, we conducted a historical cohort study on a target population of 3,628,857 inhabitants aged at least 18 years residing in Southern Iran. Results: We estimated 71.9% [95% CI: 70.7-73.1%], 81.5% [95% CI: 79.5-83.4%], 67.5% [95% CI: 59.5-75.6%], and 86.4% [95% CI: 84.1-88.8%] hospitalization reduction for those who received the full vaccination schedule of BIBP-CorV, ChAdOx1-S/nCoV-19, rAd26-rAd5, and BIV1-CovIran vaccines, respectively. A high reduction in mortality, at least 85%, was observed in all age subgroups of fully immunized population. Conclusion: The pragmatic implementation of a vaccination plan including all available vaccine options in the Iranian population was associated with a significant reduction in documented COVID-19 infection, hospitalization, and death associated with COVID-19.

Investigation of Laboratory Indicators, Clinical Symptoms, and COVID-19 Vaccination History in Children Referred to Imam Khomeini Hospital in Jiroft City, South Iran

“…This shows the effect of the vaccine on preventing hospitalization, which is consistent with the results of other studies. Mirahmadizadeh et al conducted a study comparing the effectiveness of vaccines in Iran, their results showed that the implementation of the vaccination plan, including all available vaccine options in Iran, led to a significant reduction in the incidence of COVID-19, and hospitalization related to COVID-19 was remarkedly decreased (26).…”

Omicron-Specific and Bivalent Omicron-Containing Vaccine Candidates Elicit Potent Virus Neutralisation in the Animal Model

“…In phase III clinical trial, which is currently under peer-review, a two-dose vaccine regimen was well tolerated, with no safety concerns, and conferred 70.5% and 83.1% efficacy against hospitalization and ICU admission, respectively. The vaccine has reduced hospitalization by 86.4% and deaths by 98.3% (12).…”