In March 2020, the World Health Organization (WHO) announced an epidemic of coronavirus 2019 (COVID-19), caused by coronavirus 2 (SARS-CoV-2) causing severe acute respiratory syndrome.first. With the number of deaths and cases accumulating rapidly globally2A vaccine is urgently needed. We report existing safety, tolerability and immunogenicity data from a placebo-controlled continuous dose-increase study, with blind subjects observed among 45 healthy adults, from 18 to 55 years, randomly received 2 doses, 21 days apart, 10 µg, 30 µg, or 100 µg BNT162b1, nucleoside modified mRNA vaccine, nanoparticle formulation, encoding receptor binding region Glycoprotein spikes trimeized SARS-CoV-2 (RBD). Local reactions and systemic events are dose dependent, usually mild to moderate and transient. A second vaccination with 100 µg was not performed due to a significant increase in reactivity and a significant increase in immunogenicity after a single dose versus a 30 μg dose. The concentration of IgG bound to RBD and the neutralization titre of SARS-CoV-2 in the serum increased with the dose level and after the second dose. The mean geometric median titre was 1.9 to 4.6 times that of the nursing human serum table COVID-19 at least 14 days after the SARS-CoV-2 PCR was positive. These results support further evaluation of this mRNA vaccine candidate. (Identification ClinicalTrials.gov: NCT04368728).