No needles are necessary for two newly approved Covid-19 vaccines in Asia. On Sunday, China greenlit an aerosolized mist inhaled through the mouth and nose. And Tuesday, India signed off on a two-dose vaccine delivered via nasal drops.
India’s vaccine, developed by Bharat Biotech, has been authorized for unvaccinated people, while China’s, by CanSino Biologics, is to be used as a booster, according to Aniruddha Ghosal of the Associated Press (AP).
Both are examples of mucosal vaccines, which are aimed at mucous membranes in the mouth, nose and lungs, per Nature News’ Emily Waltz. While the mRNA shots in use today robustly defend against severe illness and death, mucosal vaccines could, in theory, better protect against infection by fighting off the virus where it’s inhaled. They also might limit transmission between people—something current vaccines haven’t done as well for new variants, according to CNN’s Simone McCarthy and Brenda Goodman.
“These approvals validate the need for mucosal vaccines,” Marty Moore, co-founder of Meissa Vaccines, which is working on a nasal Covid-19 immunization, tells Nature News. “That’s the direction we need to go globally, and the United States needs to catch up.”
Scientists are developing over 100 oral or nasal vaccines worldwide, writes Live Science’s Ben Turner. Both Iran and Russia have already authorized Covid-19 mucosal vaccines, per Nature News, and in the past, these needle-free vaccines have been approved to ward off poliovirus, influenza and cholera.
CanSino’s new vaccine in China has the same ingredients as its injectible one, but a nebulizer transforms the liquid into an aerosol, per Popular Science’s Laura Baisas. Though the booster is approved, CanSino hasn’t said when it will become available, according to the AP.
A phase II trial of China’s new vaccine found it significantly raised blood serum antibody levels compared to an injected booster, suggesting it may provide better protection, per Nature News. But whether or not the boost in antibodies translates to better effectiveness remains to be seen, per the AP.
In India, Bharat Biotech did not release the results of a similar study of its nasal drops, but it announced the trial was “successful,” according to Nature News.
“The advantage with nasal vaccines is that it may get rid of the virus before it has a chance to establish itself in the lungs and replicate,” Vineeta Bal, an immunologist at the Indian Institute of Science Education Research, tells the AP.
Jin Dong-Yan, a virologist at the University of Hong Kong, tells CNN that it’s hard to know what impact the booster will have in China—where Covid lockdowns in recent weeks have impacted more than 300 million people—until scientists have more data about the protection it provides.
In a July editorial in Science Immunology, Eric Topol, director of the Scripps Research Translational Institute, and Akiko Iwasaki, a Yale University immunologist, argued that the U.S. government needs to invest in an accelerated initiative for nasal vaccines, just as it did for the development of the first Covid shots at the start of the pandemic, per Fortune’s Grady McGregor.
“Breaking the chain of transmission at the individual and population level will put us in a far better position to achieve containment of the virus, no less reducing the toll of sickness and long Covid-19,” Topol and Iwasaki write. “The prospect of achieving this with nasal vaccines is high but will only be possible with dedicated funding, priority and breaking down of any regulatory hurdles.”