COVID-19 vaccines: Where do we stand?

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was first reported in the city Wuhan, China in December 2019. The high rates of infection led to quick spread of the virus around the world and on March 11th, 2020, the World Health Organization (WHO) announced the pandemic of the Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2. The pharmaceutical companies and institutions have been working towards developing a safe and effective vaccine in order to control the pandemic. The biology of SARS-CoV-2 is briefly discussed describing the transcription of the virus and the receptor recognition. The spike protein of SARS-CoV-2 is important in the attachment of the host cell and RNA-dependent RNA polymerase (RdRp) is involved in the replication of the virus making them good candidates for drug and vaccine targets. To date many different strategies have been employed in the development of vaccines and a number of them are in the phase III of clinical trials with promising results. In this mini-review, we assessed the literature throughly and described the latest developments in SARS-CoV-2 vaccines for humans. The main benefits and drawbacks of each platform is evaluated and the possible changes in the vaccine effectivity due to naturally occuring SARS-CoV-2 mutations have been described.