New CDC advice says people are exempt from some COVID-19 quarantine rules after a 2nd vaccine dose

• "Fully vaccinated" people need not quarantine if after they are exposed to COVID-19, the CDC said.
• Full vaccination is the point two weeks after getting a second COVID-19 shot.
• The CDC said the benefits of not quarantining outweight the risks of passing on the virus.

People who have been fully vaccinated will not have to quarantine if they have been exposed to someone with COVID-19, according to newly-updated guidance from the CDC.

The new rules mean people can skip quarantine if they:

• Got the second dose of a vaccine more than 2 weeks ago, but less than 3 months ago.
• Experienced no symptoms of COVID-19 since they were exposed.

Only the Pfizer and the Moderna vaccine are being distributed in the US at the moment.

People who aren't vaccinated are still supposed to quarantine for 14 days after they have been in close contact with someone who has COVID-19.

Full protection against COVID-19 is reached by the immune system one week after the second dose of the Pfizer vaccine, and two weeks after the second dose of the Moderna vaccine, according to Insider's Hilary Brueck.

The new CDC guidance said that if a single-dose vaccine becomes available, one dose will be enough to skip quarantine after being exposed to someone who might have COVID-19.

The guidance admitted that it is not yet clear whether someone who has been vaccinated could still pass on the coronavirus to someone else.

However, in their decision, they said that less quarantining is a benefit that outweighs the risk of increased transmission.

It is not yet clear whether vaccines will protect against new variants of the coronavirus, so people who have been fully vaccinated should continue to wear masks and respect social distancing rules, the CDC said.

Public health guidelines have continued to change as experts find out more about the virus and how to treat it.

A study from the agency recently showed that wearing two masks at once, one surgical mask underneath a cloth mask, improves the protection given by about 50%.

It is not yet clear whether the vaccines continue protecting against COVID-19 beyond three months after the second dose is taken.

However, "there is confidence in protection for those 90 days following vaccination", Saskia Popescu, an epidemiologist and infection preventionist at George Mason University in Virginia, told NBC news.

The recommendations will "likely evolve" as we learn more about how long the vaccine protects against COVID-19, Popescu said.

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The CDC had previously recommended that people who have recovered from COVID-19 don't need to go into quarantine for 90 days.

The guidance will be reviewed when new data becomes available, the CDC said.