Ljubljana - After developing a vaccine against Covid-19 last year, Slovenian researchers will focus on developing a technology to spray the vaccine into the nose or mouth, the head of the research team, Roman Jerala, has revealed for the STA.

Jerala's team developed the vaccine based on plasmid DNA, which contains the code for the virus proteins and triggers the production of virus proteins in human cells. These respond by creating anti-bodies and the protective T-cells.

Trials have shown the vaccine producing a good immune response in mice and the antibodies neutralised the virus's binding to an extent similar to other vaccines or the antibodies in patients who have recovered from Covid-19.

Trials continued on hamsters, which get sick in a similar way as people. The vaccinated hamsters produced an immune response similar to mice, but hamsters have not been infected with the virus to see whether they develop symptoms, which would give the researchers an answer how well the vaccine protected them against the disease.

"Even as we published the first results, the key question was whether we would continue with clinical trials or not. Those call for time and money, which was lacking," said Jerala, a synthetic biology expert at the National Institute of Chemistry.

Now that several Covid-19 vaccines have been developed, clinically tested on people and given an emergency approval, "no one is likely to be willing to invest into clinical trials of our vaccine as well," the scientist told the STA.

This is why his team decided to develop a technology to apply the vaccine as a spray, also because Covid-19 is primarily a respiratory infection and in this way respiratory organ tissues would be better protected. A further asset of such a vaccine is that some people fear getting a jab.

"It's a technology that is interesting from the scientific and technological aspects and will probably come to be used for other viruses and vaccines as well. In this way we're preparing for potential future pandemics or diseases," says Jerala