Why a COVID-19 vaccine won't be 100% effective

A vaccine being developed
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KYW Newsradio’s Medical Reports are sponsored by Independence Blue Cross. 

By Dr. Brian McDonough, Medical Editor 
PHILADELPHIA (KYW Newsradio) — Any vaccine that is developed for COVID-19 will probably not be 100% effective and protective. This is not bad news it’s actually how many vaccines work. 

The goal of a vaccine is to protect individuals, but to also cut down spread in a community. 

The reason we emphasize the importance of masks and social distancing is to cut down spread from person to person while protecting the individual. 

An effective vaccine ideally will fool an individual's body to build antibodies to COVID-19, so that when the virus attacks, the body can fight it off. 

In some cases, it won't totally fight it off, but it will render the virus less virulent and help with symptoms and dramatically reduce the risk of death.