According to a study, a nasal spray vaccine against corona developed in Berlin has advantages compared to previous Sars-CoV-2 vaccines, at least in animal experiments. The preparation with weakened corona viruses was tested on hamsters in various schemes and compared to an mRNA vaccine, for example, as a team led by Geraldine Nouailles from the Charité reports in the journal “Nature Microbiology”. It is still an early stage and there have not been any human tests. The question of the duration of protection beyond the period of the experiment is also unclear, as co-author Emanuel Wyler from the Max Delbrück Center (MDC) told the German Press Agency.

According to the study, the results of the so-called live attenuated vaccine show that the nasal spray vaccination triggered the strongest immunity. “The effect is measured by the severity of the golden hamster’s disease,” said Wyler. Various other parameters were also tested, such as virus replication, stimulation of the immune memory and the concentration of antibodies on the mucous membranes. The authors of the Charité, the Freie Universität Berlin (FU) and the MDC 2022 had presented a version that had not yet been reviewed by external experts as a so-called preprint.

Vaccine development not so fast anymore

Safety tests are now pending in cooperation with the Swiss biotech start-up RocketVax AG, as stated in a statement on the study. The company is continuing to develop the drug and is preparing a phase 1 clinical trial in humans. “In the coming winter we will not have a nasal corona vaccine in Europe,” said Wyler. “Vaccine development is no longer going as fast as it did during the acute pandemic phase.” A nasal vaccine from the US pharmaceutical company Codagenix is ​​more advanced than the Berlin project, but the results of a phase 3 study are still pending.

With vaccines that are injected, immunity builds up primarily in the blood and distributed throughout the body. With nasal vaccines, on the other hand, it is promised that the virus will be specifically fought on the mucous membranes of the upper respiratory tract, where it first attacks. The goals also include more protection against the transmission of the virus. The previous Sars-CoV-2 vaccinations significantly reduce the risk of serious illness and death, but they offer less protection against infection with omicron. Other corona nasal vaccines were already approved in India and China in September 2022.