These vaccines “concentrate the immune protection in the upper airway,” Dr. Anthony Fauci, the White House’s chief medical adviser, told NBC News in an interview. In doing so, the “antibodies that are trying to protect you from having the virus enter your body, are right there on the front lines protecting you.”

The lack of initiative has been a disappointment for some scientists who say vaccines administered through the nose or upper respiratory tract may be better suited to preventing infections caused by the coronavirus compared to shots administered intramuscularly.

“There isn’t a lot of appetite to invest in these things anymore because Operation Warp Speed is over and a lot of people think this is all done and we don’t need better vaccines,” said Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai in New York City. He is supporting an effort at Mount Sinai to develop a nasal vaccine…

A nasal vaccine still remains far off in the United States, though that isn’t for lack of trying: There are numerous nasal vaccines for Covid in development in the country, Fauci said, but the vast majority are still in the preclinical stage or early on in human clinical trials. The National Institute of Allergy and Infectious Diseases, which Fauci directs, is funding some early research on nasal vaccines.