ABSTRACT
It is currently unknown how effective the COVID-19 vaccine is at preventing new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among the general population. The study suggests that a safe and efficient vaccination against the COVID-19 could help manage this pandemic if widely distributed. The present study aimed to investigate the effectiveness of the ChAdOx1 nCoV-19 vaccine in between vaccinated and unvaccinated cohorts. A retrospective multicenter cohort study comprised 1244 COVID-19 positive patients enrolled in this study from three different hospitals among patients who had been appropriately vaccinated or not between April and June 2021. Data were collected by face-to-face survey, and clinical investigations were obtained by observation. Descriptive statistics and the Cox proportional hazard model of survival analysis were performed in the study. Among the participants, 69% of vaccinated cohorts did not require hospitalization, and 97% successfully recovered from the infection. In respect of age, compared with unvaccinated cohorts, the vaccine effectiveness varied from 81% to 92%. The ChAdOx1 nCoV-19 vaccine was more effective among those aged 60-69 years old and reduced 92% hazard of death than the unvaccinated group [HR ratio - 0.081(.036-.179), P=0.0001]. The study found the ChAdOx1 nCoV-19 vaccine is highly effective for receivers. The COVID-19 vaccination demonstrated a significant correlation with a reduced probability of disease severity, hospital admission rate, early recovery from illness, and mortality.
ABSTRACT
Introduction: Peoples all around the world are waiting for vaccination against COVID 19 infection. In Bangladesh, Astra Zeneca (AZ) vaccine was provided, but patients had infections of SARS COV 2 even after vaccination. We focused on observing the severity, oxygen requirement and outcome of the COVID-19 infected patients who took the first dose or completed the immunization regimen. Methods: This is an observational study done among 174 COVID 19 patients from three COVID 19 dedicated hospitals of Chattogram, Bangladesh, who took AZ vaccines 1st dose or completed the schedule. All patients were Real-Time Reverse Transcription Polymerase Chain Reaction (rRT PCR) positive for COVID 19. Patients were enrolled after receiving written informed consent. Suspected cases or unwilling patients were excluded from the study. Ethical approval was granted by the CMOSH ERB. SPSS 20 was used to analyze the information gathered. Results: Among 174 vaccinated patients, 55(31.61%) completed the vaccination schedule, and 119(68.39%) took their 1st dose of the COVID 19 vaccine. Gender distributions revealed 67(38.5%) female and 107(61.5%) male got the vaccine, and 55 patients completed the full two doses, and 119 patients took the 1st dose. Most of the patients were 40 years and above. In the completed vaccination group, 33(60.0%) out of 55 in and in the first dose vaccinated group, 75(63.0%) out of 119 had a mild COVID 19, and severe and critical cases were found very minimum. Among the patients who have completed the vaccination, 32(58.2%) needed no oxygen, and who was given the first dose, 78(65%) needed no oxygen. No death occurred who completed the vaccine, and 3(2.5%) patients died who took 1st dose of the vaccine. Conclusion: Vaccine provided in Bangladesh to the people so far seems safe and effective. Severe and critical COVID 19 is low, and the need for oxygen to admitted patients is less, and the death rate is minimal.