Spike (S) protein, a major vaccine target for coronaviruses, has been assessed in different types of vaccines designed for infections caused by coronaviruses, including inactivated whole-virus particle, S protein subunit vaccine, virus-like particle with S protein incorporated into influenza virus or hepatitis virus protein, live attenuated virus with gene deletion, virus vectors (such as modified adenovirus carrying S protein) and deoxyribonucleic acid (DNA) vaccine, which encodes part or the full length of the S protein gene [26]. The gene discussed is PROS1; the disease is infection.