EXPLAINER-When will COVID-19 vaccines be generally available in the U.S.?

U.S. President Donald Trump and the head of the Centers for Disease Control and Prevention (CDC) this week disagreed about when a COVID-19 vaccine would become widely available. Trump has said one could initially be available by the Nov. 3 election, while the CDC director said vaccines were likely to reach the general public around mid-2021, an assessment more in line with most experts.

WHAT DOES IT MEAN FOR A VACCINE TO GENERALLY AVAILABLE?
General availability is when every American who wants the vaccine can get it. There are currently no COVID-19 vaccines approved by U.S. regulators, although a handful are in late-stage trials to prove they are safe and effective.

Experts estimate that at least 70% of roughly 330 million Americans would need to be immune through a vaccine or prior infection to achieve what is known as herd immunity, which occurs when enough people are immune to prevent the spread of the virus to those unable to get a vaccine.