COVID-19 was first discovered in China, which became the first country to produce a vaccine. Sinovac and Sinopharm are China’s leading vaccine makers, and both manufacture World Health Organization-approved COVID-19 vaccines. What’s the difference between the two companies? Sinovac is a privately owned company, while Sinopharm is government-run. Scientists at both companies use the same method to make both vaccines. How are the vaccines made? Dr. Andrea Cox, a professor at the Johns Hopkins University School of Medicine with a special interest in immunization, has provided expert advice to VOA about COVID-19 vaccines. Cox told VOA that scientists take a type of bacteria — or in this case, a virus — and inactivate or kill it. They then inject it into people. Because the virus is dead, it can’t infect anyone. Then, if a vaccinated person is exposed to the live virus, that person’s body recognizes it and fights it off. Are these vaccines effective? According to Cox, the Chinese vaccines are not as effective as the Moderna, Pfizer-BioNTech, AstraZeneca and…