Phase III Vaccines for SARS-CoV-2: A Review of Development and Available Data

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has caused more than 35 million confirmed cases and more than 1 million deaths so far. This has led to global efforts to find effective treatment and vaccination to control disease transmission and decrease severity. The current efforts are focused on developing a vaccine that is safe and effective after one or two doses, provides protection for a minimum of six months, provides protection for high-risk population and reduces the risk of onward viral transmission. In this review, we summarize available information related to the development and safety profile of these phase III vaccines against SARS-CoV-2. Methods Literature search was performed on PubMed, Cochrane and ClinicalTrial.gov using keywords like “SARS-CoV-2”, “COVID-19”, and “Phase III vaccines”. Two individuals performed screening of the resultant library. We assessed different articles for information focusing on vaccines in phase III trials. Results As of September 3, 2020 update by the World Health Organization (WHO), there are currently more than 137 candidate vaccines undergoing preclinical development and of these 34 candidate vaccines are in the clinical evaluation phase, 18 are in phase I and 5 are in phase II. Currently, there are 9 vaccines in the phase III development process. Conclusion Multiple phase III trials of COVID-19 vaccines are in progress across the globe, highlighting the collaborative international efforts to develop a safe and effective vaccine. The available efficacy and safety data of phase I/II trials of these vaccines have shown promising results. Pharmaceutical companies are using different strategies including inactivated vaccines, RNA vaccines, recombinant viral vector vaccines and live attenuated BCG vaccine.