Transcript for CDC changes quarantine rules for fully vaccinated people
Now to the coronavirus emergency and new quarantine rules from the CDC this morning for people who have been fully so far more than 33 million people have received at least one shot here in the U.S. Whit Johnson is live at the mass vaccination site at Citi field in New York City with more. Good morning, whit. Reporter: Robin, good morning to you. Citi field home of the mets has never looked quite like this. Take a look behind me. You can see the registration tables here. People will come in and then they'll be escorted around the corner and that's where the vaccines are being administered. Due to low supply, the stadium is only able to offer about 200 doses per day initially, but they do hope to ramp that up to about 5,000 doses per day in the coming weeks. This as the CDC now says that some people who are fully vaccinated can skip the quarantine if exposed. This morning, the CDC saying quarantine is no long Ernest for some people who are fully vaccinated after exposure to covid-19. W guidelines would apply more than two weeks has their final dose allowing for immunity but only within a three-month period following that dose because it's still unclear how long protection lts. And as long as people remain asymptomatic since exposure. The CDC also revealing in a new study that tight-fitting masks or double masking wearing a cloth mask over a surgical mask could reduce the risk of transmission by more than 95% in this fau simulation they demonstrate how particles are released. The bottom line is this, masks work and they work best when they have a good fit and are put on correctly. Reporter: Proper mask use growing more urgent with new variants raging across the in California governor Newsom announcing the first two cases. Highly contagious south African variant in addition to 159 cases of the variant from the uk. We have vaccines that work well against it and obviously we're going to be planning if necessary to upgrade vaccines in the future if we ever have to do that. Reporter: In New York good news for sports fans, governor Cuomo announcing large arenas can soon re-open at 10% capacity. Madison square garden planning to host roughly 2,000 fans starting February 23rd when the Knicks face the warriors. Now, if you do plan to attend one of those large-scale sporting events in New York you will have to submit a negative covid test result within 72 hours, George. Thanks very much.
This transcript has been automatically generated and may not be 100% accurate.