KYW Newsradio's Medical Reports are sponsored by Independence Blue Cross.
By Dr. Brian McDonough, Medical Editor
PHILADELPHIA (KYW Newsradio) — Clinical trials for covid vaccines are entering the third phase, which could be the most important phase.
Clinical trials usually follow three phases, with the first two focused on questions of safety and dosing. In the third phase, it's time to see if the vaccine actually works.
These vaccine trials depend on volunteers getting exposed to COVID-19 as they live their life: the incidence of illness in the treatment group compared with the placebo group shows how effective the vaccine is. There is good news and bad news.
The good news is that these trials are some of the largest ever attempted, but the disturbing news is that they are being done faster than ever. Another important point to note is that scientists don't expect a 100% effective vaccine.
The FDA wants at least 50% efficacy for a COVID-19 vaccine. And remember, the vaccine is designed to do two major things: protect the recipient if possible, and reduce the spread of the virus in the overall population.
