Vaccines for COVID-19: An Overview.

The advent of the COVID-19 pandemic in the final months of 2019 prompted an extraordinary response on the part of the scientific community, with fundamental research on the biology of the virus and the human immune response, and development of testing, therapeutics, and vaccines occurring on an unprecedentedly short timescale. Within a year after the worldwide outbreak of the disease, more than 40 vaccine candidates had emerged, with 21 candidates in phase 3 trials or already being used on an emergency basis. Many of these vaccines have involved innovative platforms. In this concise review, the authors will summarize the characteristics and performance of the leading vaccines and discuss considerations of virus mutations and asymptomatic spread that may affect the ability of the worldwide community to use these vaccines as a means to defeat the pandemic and restore pre-COVID-19 normality.