Effectiveness and Possible Side effects of the Covishield Vaccine in Preventing Covid-19

This review evaluates the Covishield vaccine, which was developed by AstraZeneca and is produced in India by the Serum Institute, focusing on its effectiveness and potential side effects. The analysis employed various study designs, including test-negative case-control studies and cohort studies, to assess the vaccine's performance in preventing COVID-19 across diverse populations. The findings indicate that Covishield provides substantial protection, with a single dose offering approximately 49% effectiveness and two doses increasing the effectiveness to around 54% in preventing COVID-19 infection. Importantly, the vaccine demonstrates high effectiveness—about 95%—in preventing severe cases of COVID-19 that require oxygen therapy, highlighting its role in mitigating serious disease outcomes. Common side effects reported following vaccination include malaise, headache, fatigue, and fever. These symptoms generally onset 6-8 hours after vaccination and resolve within 24-100 hours. Additionally, some cardiovascular adverse events, such as tachycardia and hypertension, were noted, though their causal link to the vaccine remains unconfirmed. Overall, Covishield proves effective in reducing both the incidence of COVID-19 infections and the severity of the disease, with side effects that are typically manageable and transient.