(CNN) As the more contagious Delta variant of the coronavirus sweeps across the United States, doctors are concerned it could create another spike in Covid-19 cases in the fall, especially in areas where vaccination levels are low.
While many Americans have taken the opportunity to get vaccinated against the coronavirus, children younger than 12 are still unable to receive the vaccine.
Unvaccinated people -- including children -- are more vulnerable because it is more transmissible, said CNN Medical Analyst Dr. Leana Wen, an emergency physician and visiting professor of health policy and management at the George Washington University Milken Institute School of Public Health. She's also the author the forthcoming book "Lifelines: A Doctor's Journey in the Fight for Public Health" and the parent of two young children.
"I'm concerned about the Delta variant," US Surgeon General Dr. Vivek Murthy told CNN Wednesday. "I am worried that what we are seeing in terms of a plateauing of cases nationally but also an increase in cases in many small sections of the United States, that is, in fact, being driven by the Delta variant."
Parents have the freedom to decide how they want to protect their children, Wen said, but there are some strategies to lower their children's risk of contracting the Delta variant.
CNN: How is the Delta variant different from the original strain of Covid-19?
Dr. Leana Wen: There are three things that we should assess when looking at new variants. The first is transmissibility. The Delta variant is about 60% more transmissible than the Alpha variant, which was the one that was already more contagious than the existing wild-type variants that were in the US. Unvaccinated people are even more likely to get infected with the Delta variant than any of the other variants we've seen thus far during the pandemic.
The second consideration is virulence. There is some UK data that suggests that people who are infected with the Delta variant are more likely to be hospitalized and to experience severe illness.
The third is about whether the vaccines we have will provide immune protection against the Delta variant. It does appear that the vaccines we have do work against the Delta variant. They appear to be less effective against Delta than they were against Alpha and other previously dominant variants.
CNN: Children younger than 12 in the US are not eligible for Covid-19 vaccines yet. How careful do parents need to be?
Wen: This is something I think a lot about as a parent of two young children, ages 1 and almost 4, and why I have been very concerned about the lifting of indoor mask mandates. I'm not concerned about my children or other unvaccinated children who are around fully vaccinated people, but I'm very concerned about unvaccinated people being around others who are also unvaccinated -- whether they're children or adults.
Because the Delta variant is so much more contagious, there is no room for error. If there is somebody who is infected who is unvaccinated and there are other unvaccinated people around, there is a higher likelihood that those unvaccinated people are going to contract Covid-19 -- and that includes children. I would continue to urge unvaccinated people to behave as if there is high risk to them because the pandemic is not over for those who are unvaccinated.
CNN: What are some specific strategies parents can implement to keep their unvaccinated children safe?
Wen: Different parents are making different decisions when it comes to risk, and that's OK. My family is choosing to be very cautious for the time being. And what that means is we are happy to have our children participate in playdates and socialize in outdoor settings. We invite people over to our backyard; we go to other people's backyards and meet other families in pools and parks. It's not necessary for kids to wear masks outdoors, and we do not socialize with unvaccinated people indoors.
CNN: What should parents take into consideration when sending their children to summer camp?
Wen: My son is going to a camp that is predominantly outdoors. We're happy to do that and not wear masks in outdoor spaces. If we're indoors, we will only have our children be around other fully vaccinated people. If they're going to be indoors with other people who are unvaccinated at camp, they need to be wearing masks. Ideally, meals at camp are served outdoors. If they are served indoors, kids should be spaced at least 6 feet apart while eating and not wearing masks.
For camps for those 12 and older, ideally, they require vaccination. If they do that, then it would be a very safe environment and they can do away with masks and distancing. If there are people of mixed vaccination status, then masks should still be required indoors.
Every family needs to decide the level of risk that they want to take together as a household. Some families might be OK with their children engaging with others indoors who are unvaccinated. Many parents will want to be more cautious. And if that's the case, they might consider asking the camp if they could impose a mask mandate. If most other kids are not wearing masks, and your child is made uncomfortable for the choice to mask indoors, parents could consider pulling their kids out.
CNN: For families hoping to travel this summer, what should parents look out for when traveling with their unvaccinated children?
Wen: Again, this depends on the risk tolerance of the family, and mine is being particularly cautious. We are very comfortable traveling by car because we're able to control the places that we stop at. We're also comfortable staying in an Airbnb or a hotel and going to outdoor restaurants, but we're not going to go to indoor restaurants with our unvaccinated children.
We would take my almost 4-year-old, who is very good about masking, on a flight. With my 1-year-old, who cannot wear a mask, we would not.
If you're visiting an amusement park, they can be safe and low risk if you stick to outdoor activities. Avoid indoor settings and try to avoid places with large crowds.
The travel itself isn't what worries me the most. It's what people choose to do once they get to their destination. Make sure that the kids are also staying outdoors for meals. We don't want for there to be a lot of care taken, for example, wearing a mask on a flight or staying outdoors at an amusement park, only for the entire family to go to an indoor restaurant or to socialize with extended family or friends indoors who are unvaccinated.