Dr. Scott Gottlieb: High-quality Covid masks work even if others around you aren't wearing one

People concerned about getting Covid can still protect themselves by properly wearing masks, like an N95 or KN95, even if nobody else around is, Dr. Scott Gottlieb told CNBC on Wednesday.

Gottlieb's comments come two days after a federal judge in Florida nullified the Biden administration's Covid mask mandate for public transportation, including airlines. Many mask rules for other settings have already been relaxed.

"If you have a good-fitting mask, a high-quality mask on and you're wearing it well, you're going to afford yourself a high degree of protection," the former Food and Drug Administration commissioner said on "Squawk Box." "One-way masking does work," he added.

"So people who feel vulnerable, if they continue to do that, are going to be able to protect themselves in that setting even if other people aren't wearing masks," argued Gottlieb, who now serves on the board of Covid vaccine maker Pfizer.

In response to the Florida ruling, the Transportation Security Administration indicated it will not enforce the pandemic policy; major U.S. airlines also said they'd no longer require masks.

The Department of Justice signaled Tuesday it will likely appeal the ruling from U.S. Judge Kathryn Kimball Mizelle, who was appointed by former President Donald Trump in 2020.

The end of the public transit mask requirement has been met with relief by some and concern by others, especially people who have underlying health conditions that make them more vulnerable to serious Covid illness.

While many public-health mitigation measures for places like sports venues and restaurants have ended, supporters of the mask mandate for public transit note that some people have no choice but to commute via trains and buses. For that reason, they believe the policy is an important layer of protection against Covid, particularly in light of more transmissible variants.

Gottlieb said he thinks the Center for Disease Control and Prevention should've let the mask mandate expire Monday, instead of deciding last week to extend the policy to May 3. However, he acknowledged that people "will be made to feel vulnerable by this policy ... especially children under 5 who have health conditions and can't be vaccinated" and the immunocompromised.

At the same time, Gottlieb said he believes "the masks were probably providing a lot less protection than people assume because most wore cloth masks," not the highly protective N95s and KN95s.

"For people who feel at risk, I would submit that one-way masking still does work," reiterated Gottlieb, who led the FDA from 2017 to 2019 in the Trump administration. He again stressed the need for it to be a high-quality mask. "I'm still going to wear a mask in certain occasions where I feel I'm in a confined space and there's a lot of people around, where I'm in environments where [Covid] prevalence are higher," he added.