Scientists have developed a revolutionary vaccine that does not require refrigeration or booster shots, making the so-called nanovaccine a potential “game-changer” in curbing disease in the developing world. Experts believe the drug, which is delivered in a nose spray, could extend immunization to millions of people who are not now vaccinated against dangerous, infectious diseases.
Scientists say the vaccine is the first to use nanoparticles, a relatively new technology in medicine that embeds proteins from disease-causing organisms into tiny, polymer spheres five hundred times smaller than the width of a human hair.
Balaji Narasimhan, a chemical engineer at Iowa State University, led a team of researchers that developed the nasal spray. Like other vaccines, the protein-containing nanoparticles contained in the spray prime the body’s immune system to recognize and mount a protective response against dangerous diseases without actually causing illness.
Narasimhan says a huge advantage of the nanovaccine is that it does not require refrigeration, which is challenging in remote parts of the world and drives up the cost of traditional vaccines.
“The price of the vaccine would go down," he said. "But the logistics of employing these vaccines into various parts of the world would also be tremendously impacted by a room temperature storage vaccine that would not need refrigeration.”
Narasimhan says nanovaccines developed in the lab remained effective for up to six months without refrigeration.
A nanovaccine can be designed to target any disease, according to Narasimhan, by sealing proteins from the pathogens inside the spheres.
Researchers have so far developed experimental vaccine sprays against influenza and pneumonia, as well as a number of bioterrorism agents, including plague and anthrax.
Narasimhan says designer nanovaccines could potentially be used to contain emerging infectious diseases such as SARS, new influenza strains and drug-resistant tuberculosis. They can even be formulated to include antibiotics and antimicrobials to help treat disease.
A person only needs to be immunized once with a nanovaccine. Narasimhan says boosters are not needed to resensitize the immune system against a disease because of the way the nanoparticles work.
“When they come into contact with the body, the body fluids, water mainly, degrades the particles," he said. "And as the particles degrade, they release that protein slowly. So that slow release of the protein is what essentially gives the body the type of memory that it acquires to remember the infection and obviates the need for a booster shot.”
Narasimhan envisions someday having nanovaccines against any number of tropical diseases, including cholera, diphtheria and dengue fever, once researchers identify target proteins.
Balaji Narasimhan unveiled his nanovaccine at the annual meeting of the American Chemical Society in Dallas, Texas.