In the U.S., more than 10% of the population has already received two doses of the COVID-19 vaccine. As more people get vaccinated, many have questions about what is safe to do during this stage of the pandemic.

We talked to Dr. Jonathan Grein, director of Hospital Epidemiology at Cedars-Sinai, about what you can do after you've received the COVID-19 vaccine, whether or not you can still transmit the virus and what people should know about coronavirus strains, herd immunity and when the pandemic might end.

Dr. Jonathan Grein: Here's what we know from data about the vaccine so far: The COVID-19 vaccines are excellent at preventing people from getting severely ill from coronavirus. The vaccines are very effective at preventing severe illness from the disease.

What we don't know is if it's possible for people to still get infected with the virus that causes COVID-19 after getting vaccinated and still transmit the virus to others. There is some preliminary data that is very encouraging, but we don't yet fully understand how well the vaccine prevents the virus from spreading yet. There's a lot of active research happening right now to answer that question.

JG: The Centers for Disease Control and Prevention (CDC) has released guidance for fully vaccinated people which says that those who have been fully vaccinated (meaning two weeks after their second dose of a two-dose COVID-19 vaccine, or two weeks after a single-dose COVID-19 vaccine) can now do the following:

• Gather indoors with fully vaccinated people without wearing a mask
• Gather indoors with unvaccinated people from one other household without masks, unless one of those people has an increased risk of severe illness from COVID-19

Even after getting vaccinated, it's important to keep practicing physical distancing, wash your hands frequently and minimize interactions with others outside your household. Not enough of the population is vaccinated yet to let our guard down, especially in public settings.

Right now, we're all feeling very encouraged that COVID-19 case counts are dropping, both at the local and national level. When the virus is in retreat like this, now is actually the time to double down on prevention tactics and not slack.

JG: The more that a virus spreads, the more likely it is that variant strains will emerge. Recently, a new strain of SARS-CoV-2, the virus that causes COVID-19, has been found in patients across Los Angeles County, as well as other parts of the world. This is to be expected, but it doesn't necessarily mean the vaccine will be less effective against them.

At this point, with the information we have on these new strains, it seems very likely that COVID-19 vaccines will remain very effective at preventing severe illness. While there might be some reduction in the level of effectiveness, the current COVID-19 vaccines still remain a powerful tool against new coronavirus strains.

JG: Eating indoors remains a relatively high-risk practice because it requires people to remove their mask in close proximity to others outside their household, and most people have not yet been vaccinated. The Centers for Disease Control and Prevention (CDC) advises people to avoid poorly ventilated indoor spaces.

I anticipate outdoor dining and limited indoor activities to be the norm for a while. The CDC is still advising people to eat outdoors, if possible.

JG: All public health measures are still in place for traveling. As of Feb. 10, 2021, masks are required on planes, buses, trains and in U.S. transportation hubs, such as airports.

Until we learn more about how well the vaccine prevents spread of the virus, and how long immunity lasts, it's still extremely important to follow all public health recommendations if you have to travel (e.g., masking, maintaining physical distance, frequently washing your hands), even if you've been vaccinated. Getting vaccinated should not be considered a "free pass" to travel.

JG: That's a difficult question to answer. Herd immunity is an epidemiological concept that describes how many people need to be immune to reduce transmission in an area. Knowing the exact number needed to reach that level can be difficult to predict. Right now, our focus needs to be on getting as many people vaccinated as possible. As that happens, and as we see the rates of infection go down, then we will start to see an easing of public health restrictions.

JG: As we get more of the population vaccinated, we'll begin to see a relaxation of some of the more restrictive public health measures to slow and prevent the spread of coronavirus.

The reality is, we're not going back to a pre-pandemic "normal" for some time. However, I am optimistic and believe we'll get to a point where infection rates and the severity of illness caused by COVID-19 will be mitigated by vaccination, herd immunity and our immune response to the virus.

If coronavirus does become endemic (when a disease is constantly present in a population), it is possible that as our immune system gains more experience with this virus (either through vaccination or natural infection), that infections become less serious over time, and less likely to land people in the hospital.