Delta variant: 6 things to know about the highly contagious coronavirus strain

After declining sharply for months, COVID-19 cases are climbing in the U.S. once again as a result of the Delta variant, which some experts have called “the most troubling variant by far.”

Yahoo News medical Contributor Dr. Kavita Patel, a primary care physician in Washington, D.C., explains what we've learned so far about the fast-spreading strain, and how to protect yourself and loved ones from it.

Video transcript

KAVITA PATEL: We're now seeing at least 83% of new cases attributed to the Delta variant. That's likely an under count. It's pretty close to 100, most likely, percent of new cases would be found to be the Delta strain. We're seeing a rise in cases, almost 30,000 cases a day. The majority of them are in unvaccinated people. And if you are unvaccinated, you're opened to an incredible amount of likelihood that you could get infected.

We now have mounting evidence that the Delta strain itself reproduces in people's nasal passages, mouth, and body faster, up to 1,200 times higher than previous coronavirus strains. So it just replicates faster. And then number two, we know that it also is easier to give and to get, meaning that you don't have to be around someone for very long in order to get it.

We do not think it leads to higher-than-expected deaths or hospitalizations. But there's still some ongoing research that we need to have to be certain of that. But that's actually good news, in the sense that you don't see a more kind of what we call virulent or a strain that is causing people to die at a higher rate or to be hospitalized at a higher rate. That's all for unvaccinated people.

The average age of hospitalized patients with COVID now is younger. It's in the 25-to-40-year age range. And we're seeing also with new cases a number of pediatric infections. It's not at a higher rate than adult infections or what we would expect. But it is a great number of infections are in children. And again, this reinforces that this is primarily happening in unvaccinated people.

In children, we're only seeing about 1% of the cases leading to hospitalization compared to 15% to 20% of adult cases leading to hospitalization but again, all unvaccinated, for the most part. And the reason that we're seeing cases in younger people is simply because almost 90% of older Americans, especially over the age of 65, have had at least one shot of the vaccine. So in essence, they are no longer kind of easy for the virus to infect. So the virus just goes to a population that it can. Then it's infecting people who are not vaccinated, which tend to be younger people, in general.

Some of the symptoms we're seeing are classic COVID symptoms, loss of smell, loss of taste, fevers, and cough. But we're also seeing what I would characterize as symptoms that I would normally see in a common cold, runny nose, sometimes itchy eyes. Sometimes people think that they're allergies. And in many cases, they might be. But they're not necessarily those classic symptoms of a fever or loss of smell or taste. So I'm encouraging to anybody who's had symptoms of any kind that they are not normally experiencing that they should go to a doctor or somewhere where they can get a rapid test to find out within minutes if they might have COVID.

If you are vaccinated, remember you are safe from death and hospitalization, but you still might be able to actually get what we call a breakthrough infection. It's not 100% coverage with vaccines. They don't prevent you from getting infected. So it's not surprising to see breakthrough infections.

But what we don't have data on is whether you get vaccinated, get a breakthrough infection, maybe have no symptoms, but you might pass it to someone who's unvaccinated. We are waiting to kind of have the clinical data to confirm if that might be the case, which is why we're telling everyone if you're in a mixed household and you've got unvaccinated people in your household, that you should make sure you take precautions.

There's no doubt that the best way to protect anyone is to get vaccinated. And by far, the mRNA vaccines have shown and demonstrated incredible efficacy. So I would encourage everyone to create a line of defense for their unvaccinated children by getting vaccinated yourself. And then avoid congested areas.

Treat your children as if they are incredibly vulnerable to getting infected. They should be wearing a mask. They should avoid congested indoor spaces. Choose outdoor spaces, spaces with great air ventilation.

And then the quality of your masks matter. For kids, you really want to try to just protect and cover their nose and mouth as efficiently as possible. Adults who are vaccinated, by and large, really have no reason to continue wearing a mask. But if you have children in your household, it's always a good idea to keep the behavior consistent and do what you're asking them to do.

And those are definitely important tips to consider until we have widespread pediatric vaccinations available. It's why the American Academy of Pediatrics made a very bold statement that any child over the age of two, even those that are immunized over the age of 12, should be wearing masks in school this fall.