COVID-19: The True Value of Vaccines

Vaccines protect the body from infectious diseases. Despite the large number of pathogens that exist, only a few vaccines have been developed. Ensuring the safety and effectiveness of vaccines is very difficult. We look at the history of vaccines, as well as how they are made and how they prevent disease. The COVID-19 vaccine that's closest to completion is a new type. Experts offer their input on its safety and effectiveness.