(NewsNation) — The Centers for Disease Control and Prevention says masks are still needed despite the fact that planes and other forms of public transit have ditched the mask mandates following a ruling by a judge in Florida.

The Justice Department has decided to file an appeal in the case, trying to overturn that judge’s order. But as of right now, almost everywhere, it is up to Americans to decide whether or not to mask up on public transportation. The developments over the past few days have people asking a lot of questions, especially when it comes to safety.

Dr. Monica Gandhi is with the University of California San Francisco and joined “NewsNation Prime” on Wednesday to discuss who should still wear masks, and what other ways they can protect themselves. This interview transcript has been edited for clarity:

Marni Hughes: Dr. Gandhi, I feel as though I’ve got a bit of mask whiplash. Wear the masks, don’t wear the mask, maybe we’re going to have to wear the mask again. What is your message to the traveling public right now?

Dr. Monica Gandhi: You know, we are at our lowest hospitalizations in the last two years. They continue to be low. They dropped 4% the last two weeks, ICU admission is down 28% and deaths are down 37%. We are in a good phase of the pandemic. It’s why masks are not required indoors in multiple places. People are gathering, people are together, people are without masks and there isn’t that much evidence that we need to do this right now — that we need masks on public transportation. Actually, people are wearing a bunch of different masks and half of them don’t work, half of them are falling off. I think that it’d be best to just let this [ruling] be.

Hughes: But the CDC is our top health agency, so what information are they looking at? Because they are still saying, “We want you wearing masks.”

Gandhi: I think this is partially because they want the authority to put back public health measures when needed. I think it’s a symbolic gesture to reply [to the ruling]. I think they know that we’re well within the parameters of low community levels in all of our counties across the United States. We’re really in a good place. President Biden is going to the White House Correspondents Dinner on April 30; he won’t be wearing a mask and there’ll be many people there. We trust in our vaccines. And 95% of us have antibodies to the virus. So I think they know where we are in the pandemic. It could be just to retain authority for the future.

Hughes: It does seem that there’s a lot of politics involved. Who’s primarily getting really sick right now? Is it still the unvaccinated when you look at the hospitalizations?

Gandhi: It’s two groups. Essentially, our hospitalizations again are very low. I have one person in my hospital with COVID. But it’s two groups: unvaccinated adults who still declined to be vaccinated, and older people who haven’t gotten that third dose. We need the third dose for older people. We need the fourth dose for those over 80. And then very immunocompromised — not just routinely immunocompromised. My father has cancer and is on chemotherapy. That is not decreasing his immune response. We’ve got to keep that in mind. These are great vaccines. It’s very profoundly immunocompromised patients [who need to be concerned.] They should be on Evusheld, which is something that protects them for six months. But that’s why our hospitalizations are going down. We have great treatments, we have great vaccines, and we got a lot of natural immunity during the omicron surge.

Hughes: I’m glad you brought the booster and the vaccines up because we have a question from one of our viewers at home. On Instagram, mama3clark said, “I haven’t received my second booster yet. How important is the booster? I’m over 60.” So what is your overarching message for people, healthy or not, over 60 about boosters and how many shots we need?

Gandhi: I’ll tell you that I think that the fourth shot is most important for older people. So I kind of wait until you’re 80 or so [for the fourth shot], unless the cases are going up in your region. If they’re going up in your region, go ahead and get that fourth shot. You want to keep yourself as protected as possible. And only certain types of masks work. I just want to add that. if you’re going to wear a mask, wear a good fitting mask.

Hughes: Especially if you’re immunocompromised. Are you suggesting that people who are more at risk wear those masks, especially in transit, popular, crowded places?

Gandhi: Yes. We’ve seen that the mask mandates don’t make a difference. Why is that? Because everyone’s just wearing a bunch of different masks. But what one-way masking does is really protect you as an individual. If you are vulnerable, if you’re immunocompromised, I would wear a good fitting N95, KN95, FFP2 or KF94. One-way masking is going to be probably the way of the future after we get off this hump.