A pair of scientists from Israel and Portugal have developed an inexpensive and effective new nano-vaccine against Covid-19, which can be stored at room temperature and administered as a nasal spray.

The breakthrough vaccine trains the immune system against all common Covid-19 variants with the same efficiency as existing vaccines.

But it does not require an injection or a cold supply chain and cold storage, making it ideal for vaccinating at-risk populations in developing countries and in remote regions.

In addition, the scientists believe it paves the way to the development of simpler, more effective, and less expensive vaccines in the future.

Prof. Ronit Satchi-Fainaro from Tel Aviv University’s Faculty of Medical and Health Sciences developed the vaccine in collaboration with Prof. Helena Florindo at the University of Lisbon.

“The new nano-vaccine’s development was inspired by a decade of research on cancer vaccines,” said Satchi-Fainaro. “When the Covid-19 pandemic began, we set a new goal: training our cancer platform to identify and target the coronavirus.”

Satchi-Fainaro said the researchers did not rely on full protein expression via mRNA, unlike the Moderna and Pfizer Covid vaccines.

“Instead, using our computational bioinformatics tools, we identified two short and simple amino acid sequences in the virus’s protein, then synthesized them, and encapsulated them in nanoparticles.”

Eventually this nano-vaccine, a 200-nanometer particle, proved effective against all major variants of Covid-19, including Beta, Delta, Omicron, and others, she said.

The study was the cover article of the journal Advanced Science on August 8.

“Our nano-vaccine offers a significant advantage over existing vaccines because it is needle-free and administered as a nasal spray,” said Satchi-Fainaro.

“This eliminates the need for skilled personnel such as nurses and technicians to administer injections, while also reducing risks of contamination and sharps [biohazardous] waste. Anyone can use a nasal spray, with no prior training.”

Stored as powder, as effective as Pfizer

Another major advantage of the nano-vaccine is its minimal storage requirements.

Moderna’s sensitive mRNA-based vaccine must be kept at -20°C and Pfizer’s at -70°C, generating great logistic and technological challenges, such as shipping in special aircraft and ultra-cold storage from the factory to the vaccination station.

The synthetic nanoparticles are far more durable and can be stored as a powder at room temperature.

“There’s no need for freezing or special handling,” said Satchi-Fainaro. “You just mix the powder with saline to create the spray. For testing purposes [as part of the EU’s ISIDORe Integrated Services for Infectious Disease Outbreak Research feasibility program] we shipped the powder at room temperature to the INSERM infectious diseases lab in France. Their tests showed that our nano-vaccine is at least as effective as Pfizer’s vaccine.”

Aside from its value to developing countries, Satchi-Fainaro said the plug-and-play technology provides a platform enabling scientists to synthesize more effective and affordable vaccines for future pandemics.

 “[The technology] can train the immune system to fight cancer or infectious diseases like Covid-19. We are currently expanding its use to target a range of additional diseases, enabling the rapid development of relevant new vaccines when needed,” she said.

The research has received grants from the Israel Innovation Authority and Merck under the Nofar program, as well as funding from Spain’s La Caixa Foundation Impulse as an accelerated program, and support from the ISIDORe feasibility program.

It is also part of a broader vaccine platform development program at Satchi-Fainaro’s lab, supported by a European Research Council Advanced Grant.