Review on different COVID-19 vaccines approved for Emergency Use Listing by WHO until 11 July 2022: characterization, pharmacological properties, mechanism of action and adverse events.

Background: Since the outbreak of the novel Coronavirus in Wuhan and its transformation into a global pandemic, the main concern of medical systems has been to find vaccines to help the immune system overcome the virus or, at the very least, to prevent COVID-19 positive cases from deteriorating into serious conditions necessitating hospitalization. The pace of COVID-19 vaccine production accelerated, resulting in the development of the first FDA-approved vaccine (Pfizer vaccine) in less than a year. By July 6, 2022, WHO has approved 11 vaccines for emergency use. These vaccines differ in their characterization, pharmacological properties, and mechanism of action. Before vaccines can be used, their effectiveness and safety must be evaluated. Vaccine manufacturers strive for efficiency of at least 50%. To assess the vaccine's safety, manufacturers must report any adverse events that occur in trials before license approval and in populations after license approval. Main body of the abstract: The review article discussed the general approach for vaccine production, beginning with the pre-clinical stages and progressing to the approval and manufacturing stages, as well as the general types of vaccines. By July 11, 2022. WHO approved 11 vaccines for the COVID-19 emergency use listing. The review discussed these vaccines' characteristics, efficiency, shelf-life, storage temperature, structure, mechanism of action, and potential adverse events. Conclusion: According to the review article, all of the vaccines were able to stimulate immune response against the novel corona virus. Vaccine adverse events are typically similar and mild, disappearing spontaneously within a few days after vaccine administration.