Vaccine manufacturers set their sights on nasal vaccines at least two decades ago, but so far product development has remained sluggish as scientists acknowledge that only a “thin partition” separates the nasal cavity from the brain.

According to Our World in Data, more than 12 billion doses of COVID-19 vaccine have been administered around the world, all via injection.

Trying to soften up the American public for an endless parade of COVID-19 boosters and other vaccines, Dr. Anthony Fauci is now alleging the “job is not done” and the jabs “don’t protect overly well.”

Fauci made his “job is not done” statement at a recent White House gathering of scientists, doctors and federal health officials convened to brainstorm “next-generation” COVID-19 vaccines.

Nasal sprays “that people would shoot into their sinuses” are one of the options put forth as a potential game-changer, the theory being that they would offer “easy access to a key part of the immune system” and generate protection that one journalist colorfully described as both a “motion detector” and “alarm system.”

The nasal route offers advantages for manufacturers, too, including “convenience, cost, ease of administration and disposal” — and, at least hypothetically, increased odds children and adults with “extreme fear of medical procedures involving injections or hypodermic needles” will accept them.

Although nasal vaccines have been a glimmer in vaccine manufacturers’ eyes for at least two decades, product development has, for the most part, remained “sluggish,” with scientists citing safety issues and acknowledging that only a “thin partition” separates the nasal cavity from the brain.

Another factor blamed for the “slow progress” of nasal vaccines — and of potential mucosal vaccines involving oral, ocular, rectal or vaginal delivery — is the “scarcity of optimal delivery systems.”