Berlin researchers note early success with nasal spray Covid vaccine

A nasal spray vaccine against the coronavirus developed in Berlin has shown benefits over previous vaccines after it was tested on animals, according to a study.

The compound containing diluted coronaviruses was tested on hamsters on different schedules and in comparison to a currently standard messenger ribonucleic acid (mRNA) vaccine, a team led by Geraldine Nouailles from the German capital's Charité University Hospital reported in the journal Nature Microbiology.

The research is still in its early stages as there haven't been any tests on humans so far.

The co-author Emanuel Wyler from the Max Delbrück Centre (MDC) told dpa on Tuesday it is also unclear how long the vaccine protection lasts beyond the frame of the experiment.

The study shows that the results on the so-called live attenuated vaccine show that the nasal spray vaccination triggered the strongest immunity.

"The effect is assessed based on the severity of the disease in the hamsters," said Wyler.

Other factors such as virus replication, stimulation of immune memory and antibody concentration on the mucous membranes were also tested.

The authors from the Charité, the Free University of Berlin (FU) and the MDC presented a version that had not yet been reviewed by external experts as a preprint in 2022.

Now safety tests in cooperation with the Swiss biotech start-up RocketVax AG are pending, according to a statement about the study.

The company is continuing the development of the vaccine and is preparing for a phase 1 clinical trial in humans.

"We won't yet have a nasal spray coronavirus vaccine in Europe next winter," Wyler said. "Vaccine development is not as fast as it was in the acute pandemic phase."

A nasal vaccine from the US pharmaceutical company Codagenix is more advanced than the Berlin project, but results of a phase 3 trial are still pending, he said.

Vaccines that are injected build up immunity primarily in the blood and throughout the body. With nasal vaccines, they hope that the virus will be targeted at the mucous membranes of the upper respiratory tract, where it first attacks.

The goal is to increase the protection against transmission of the virus. The current vaccines significantly decrease the risk of severe illness and death but provide less protection against an infection with, for example, the Omicron subvariant of the virus.

Other coronavirus nasal vaccines in India and China were already approved for use in September 2022.