5 things to know about the virus pandemic from Dr. Tom Inglesby

President Trump on Friday announced new voluntary guidelines that Americans should wear non-medical cloth masks when out in public to help prevent the spread of COVID-19. Dr. Tom Inglesby, the director of the Johns Hopkins Center for Health Security, joined the "CBS Evening News" to speak about the benefit of masks for the general public and a possible vaccine.

Here are our top takeaways from that conversation:

1. The benefits of the general public wearing masks

After previous guidance from the administration that Americans did not need to wear masks, the new guidelines announced Friday suggested that non-medical masks could be useful in preventing the spread of the disease. Dr. Inglesby explained: "If we all wear masks in the public - even if they're crude masks, they're just made out of cloth - then the reasoning goes that we will all collectively, breathe less particles into the air and be less likely to infect each other."

2. Masks alone are not sufficient protection from COVID-19

While non-medical cloth masks may stop individuals from spreading disease – especially if they don't know they're infected – Dr. Inglesby said they "don't really protect the wearer very well from anything. While people should not have the have the sense that if they go out in the public with a cloth mask that they're suddenly protected, they're not, they need to do social distancing just like everybody else."

3. Our "best tool" is social distancing

President Trump has said he will not order a national lockdown, and eight states have yet to place their residents under stay-at-home orders. Dr. Inglesby cautioned that because a vaccine has not yet been developed, "our best tool right now is social distancing."

4. Vaccines are being developed at "breakneck speed"

On Thursday, Dr. Fauci said a vaccine for COVID-19 could be developed in 12-18 months. While the need now is urgent, Dr. Inglesby put that timeline in perspective. He told us, "I don't think anyone wants to wait that long at all, but 12 to 18 months would be breaking all records for vaccine development. So I think that is considered breakneck speed."

5. States need to track cases of COVID-19

As the country struggles to contain the coronavirus outbreak, Dr. Inglesby said there should be "a state and national database so we can see if we're making progress against this virus." He told us the tracking of cases is necessary so state health officials can "make sure that you're staying home and that all your contacts, your family, your friends, your co-workers who might have gotten exposed are also staying home for two weeks. I think that's the deal that we have to make together to get control of this."