COVID-19 vaccine therapeutic trials review: published results and registered protocols

# Background Since the emerging of Coronavirus disease 2019 (COVID-19) in late 2019 and the World Health Organization (WHO) declaring it as a pandemic, a race to develop a vaccine against COVID-19 has started worldwide and therefore huge efforts and resources have been put into achieving it. This review summarizes COVID-19 vaccines in phase III and IV. # Methods A review of the scientific literature was conducted using the medical subject heading (MeSH) word "COVID-19 vaccines" on PubMed and the words "COVID-19", “SARS-CoV-2” and “vaccine” on ClinicalTrials.gov as of January 24, 2021. The published WHO reports on candidate COVID-19 vaccines were reviewed. For clinical trials, only phase III and IV COVID-19 vaccines were included. # Results Of the 1300 citations identified on January 24, 2021, 81 were eligible and included in this review. According to WHO report of January 22, 2021, there were 237 candidates vaccines in development and among them 64 vaccines were in advanced stages of development. On the same date, on ClinicalTrials.gov, there were 66 registered COVID-19 vaccines clinical trials on phase III and IV. Thirty seven were new candidates vaccines on phase III, 23 were BCG vaccines including five on phase VI, three were measles vaccines on phase III and three were polio vaccines (one on phase VI and one on phase III). # Conclusions Despite safe and effective vaccines are available many challenges remain including logistic difficulties concerning mass production, supply, storage, cold chain, administration at community level and equitable distribution to the most vulnerable populations. Hence the need to continue preventive measures including, hand wash, wearing mask, cough and sneeze etiquette and social distancing.