Table 2.

A summary of available phase-3 trials on SARS-CoV-2 vaccines on date February 5th, 2021.

Vaccine	Type of vaccine	Phase	Patients enrolled	Country	Median follow-up time	Primary outcome	Results	Safety	Efficacy on severe cases
ChAdOx1 nCoV-19 [29]	Viral vector	2/3	23848	United Kingdom, Brazil, and South Africa	3.4 months	Occurrence of virologically-confirmed, symptomatic COVID-19.	30 (0.5%) cases among 5807 participants in the vaccine arm and 101 (1.7%) cases among 5829 participants in the control group resulting in vaccine efficacy of 70.4%.	Serious adverse events and adverse events of special interest balanced across the study arms.	No cases of severe COVID-19 in the ChAdOx1 vaccine group. In the control group there were 10 cases hospitalized for COVID-19; 2 were classified as severe COVID-19, including one death.
								A case of transverse myelitis was reported 14 days after ChAdOx1 nCoV-19 booster vaccination as being possibly related to vaccination, with the independent neurological committee considering the most likely diagnosis to be of an idiopathic, short segment, spinal cord demyelination.
mRNA- BNT162b2 [23]	RNA	2/3	43548	152 sites worldwide (mostly United States)	2 months	Occurrence of COVID-19 starting 7 days after the second injection of the vaccine	8 cases (0.04%) of Covid-19 among participants assigned to receive BNT162b2 and 162 (0.86%) cases among those assigned to placebo resulting in vaccine efficacy of 95%.	More BNT162b2 recipients than placebo recipients reported any adverse event (27% and 12%, respectively) or a related adverse event (21% and 5%).	1 case of severe COVID-19 in the BNT162b2 vaccine group. In the control group there were 9 cases of severe COVID-19.
								BNT162b2 recipients reported more local reactions than placebo recipients (mild-to-moderate pain at the injection site was the most commonly reported local reaction, with less than 1% of participants reporting severe pain).
								Four related serious adverse events were reported among BNT162b2 recipients (shoulder injury related to vaccine administration, right axillary lymphadenopathy, paroxysmal ventricular arrhythmia, and right leg paresthesia).
mRNA-1273 [24]	RNA	3	30420	United States	64 days	Occurrence of COVID-19 starting 14 days after the second injection of the vaccine	11 cases in the vaccine group (3.3 per 1000 person-years) and 185 cases in the placebo group (56.5 per 1000 person-years), indicating 94.1% efficacy of the mRNA-1273 vaccine.	The frequency of medically attended adverse events (9.7% vs. 9.0%) and serious adverse events (0.6% in both groups) were similar.	No cases of severe COVID-19 in the vaccine group. In the control group there were 30 cases of severe COVID-19, including one death.
								Adverse events at the injection site occurred more frequently in the mRNA-1273 group than in the placebo group after both the first dose (84.2%, vs. 19.8%) and the second dose (88.6%, vs. 18.8%). However, these events were of low severity.
Gam-COVID-Vac [28]	Viral vector	3	21977	Russia	48 days	Occurrence of PCR-confirmed COVID-19 starting 21 days after the first dose.	16 (0.1%) cases among 14.964 participants in the vaccine arm and 62 (1.3%) cases among 4902 participants in the control group resulting in vaccine efficacy of 91.6%.	The most common adverse events were flu-like illness, injection site reactions, headache, and asthenia. 30 adverse events were grade 3 (0.38%). None of the serious adverse events were considered associated with vaccination.	No cases of moderate or severe COVID-19 in the Gam-COVID-Vac vaccine group. In the control group there were 20 cases of moderate or severe COVID-19.