Researchers in Hong Kong are developing an intranasal vaccine that would offer protection against COVID-19 at its point of attack.
The first phase of human tests will start next month, said Yuen Kwok-Yung, chair of infectious diseases in the University of Hong Kong’s department of microbiology.
Their goal is to come up with the “vaccine of choice,” as the world looks to build on the first wave of products, he said.
Oslo-based Coalition for Epidemic Preparedness Innovations has provided funding to the project and is open to further investments in vaccines that are taking unconventional approaches in curbing the virus.
However, questions about the durability of nasal vaccines have yet to be resolved, and they’re at an early stage.
Despite the advantages, the devices are also more complex, according to Nick Jackson, head of programs and technology at the CEPI.
Most early vaccine developers focused on injection as the fastest way to protect the world from disease.
Inhaled vaccine makers are counting on some of the unique features of the lungs, nose and throat, which are lined with mucosa. This tissue contains high levels of immune proteins, called IgA, that give better protection against respiratory viruses.
“The first generation of vaccines are probably going to protect a lot of people,” said Michael Diamond, an infectious disease specialist at Washington University in St Louis.
“But I think it’s the second- and third-generation vaccines – and maybe intranasal vaccines will be a key component of this – that ultimately are going to be necessary. Otherwise, we’ll continue to have community transmission.”
In a study of mice in August, Diamond and his team found that delivering an experimental vaccine via the nose created a strong immune response throughout the body; the approach was especially effective in the nose and respiratory tract, preventing infection from taking hold.
Experts also said vaccines that were sprayed into the nose or inhaled may hold other practical benefits. They don’t require needles, may not need to be stored and shipped at low temperatures and can reduce the need for health workers to administer them.
“When you’re thinking about trying to deliver that across the world, if you don’t need to have an injectable vaccine, your compliance goes up because people don’t like getting shots,” said Frances Lund, a University of Alabama at Birmingham immunologist working with biotech Altimmune Inc. on an early-stage nasal inoculation.
“But secondly, the level of expertise needed to administer that vaccine is significantly different.”
Altimmune, based in Gaithersburg, Maryland, plans to enter human testing with a nasal vaccine in the fourth quarter after positive studies in mice.