13 June 2023

Nasal vaccine against coronavirus further improved

Research Team at Freie Universität Berlin Increases Safety of Attenuated Live SARS-CoV-2 Vaccine.

It was only in early April that it became known that Berlin scientists had successfully tested a mucosal vaccine against Corona in animals. Now researchers at Freie Universität Berlin have further developed their live SARS-CoV-2 vaccine to be administered via the nose and increased its safety. They now present this modified form of the previously described live vaccine in the journal Molecular Therapy. 

In early April 2023, a team of scientists from several Berlin research institutions presented a live SARS-CoV-2 vaccine in the journal "Nature Microbiology", which has superior efficacy compared to intramuscularly administered vaccines. In preclinical trials, this vaccine, administered via the nose, produced better immunity at the mucous membranes of the respiratory tract than previously used vaccines administered intramuscularly. 

The nasal vaccine described in "Nature Microbiology" is a so-called live attenuated vaccine. For this, the SARS-CoV-2 virus was modified in such a way that it no longer causes disease, but is still able to penetrate body cells and thereby trigger an effective immune response. With such live vaccines, high safety of use is paramount. The originally developed form of the preparation could be transferred through close contact between laboratory animals.

Now the researchers are presenting a modified version of the vaccine in the journal Molecular Therapy. This variant of the vaccine is no longer transmissible due to a targeted change in the spike protein of the virus, but has the same efficacy. This leads to the expectation that when used in humans, a vaccinated person cannot transmit the vaccine to an unvaccinated person, even in close contact.

"A non-transmissible vaccine virus could prevent unintentional spread of the vaccine in a population," says Dr. Jakob Trimpert, a veterinarian and working group leader at the Institute of Virology at Freie Universität Berlin. Beyond the question of contagion, the current publication sheds light on other essential aspects of the vaccine's safety.

The safety and efficacy of the live vaccine developed at Freie Universität Berlin, which has now been demonstrated in several studies, gives reason to hope for good results in the upcoming clinical trials in humans. To conduct these studies, Freie Universität Berlin is working closely with the Swiss company Rocketvax AG, a subsidiary of Swiss Rockets AG.  

Vladimir Cmiljanovic, Ph.D., CEO of RocketVax, stated, "The results of these studies have important implications for the development of a highly safe and effective nasal vaccine against coronavirus. The modified version of the vaccine presented in the journal Molecular Therapy eliminates the problem of unintended spread and represents a significant advance in vaccine safety. This breakthrough brings us closer to the successful introduction of this live attenuated vaccine in upcoming clinical trials and gives us hope for comprehensive protection against COVID-19."

About the study

The study was conducted as part of a joint project of the Swiss National Science Foundation (SNF, National Research Program "Covid-19", NRP 78) and the German Research Foundation (DFG) "Recoding the SARS-CoV-2 Genome - A Multidisciplinary Approach to Generate Live-Attenuated Coronavirus Vaccines" and in collaboration with Rocketvax AG.


Julia Adler et al (2023): A non-transmissible live attenuated SARS-CoV-2 vaccine, in: Molecular Therapy, https://doi.org/10.1016/j.ymthe.2023.05.004

About Rocketvax AG

Rocketvax has its foundation in the ties between Swiss Rockets AG, a Swiss incubator and accelerator for startups with innovative therapies, and a team of expert scientists from the Universities of Basel and Zurich, the ETH Zurich, the University Hospital Basel, the Swiss Tropical and Public Health Institute in Basel, and Gigabases Switzerland AG, a spinoff of ETH Zurich.

RocketVax’s first group of vaccines addresses the SARS-CoV-2 virus and are currently undergoing preclinical testing while preparing for the production of the vaccines for human clinical trials. At Rocketvax, proprietary molecular biology technologies are used to develop novel vaccines for infectious diseases like COVID-19, cancer, and auto-immune disorders. Several vaccine candidates in the pipeline are being developed. They include the original live, single-cycle virus vaccine, live-attenuated vaccines against SARS-CoV-2, and a vaccine candidate against cancer.

About Swiss Rockets AG

Founded in 2018, Swiss Rockets AG is implementing a paradigm shift in healthcare. Patients benefit from new therapies developed with innovative and pioneering methods. The Swiss Rockets AG team combines expertise and experience to create innovative medicines focused on cancer and viral diseases.

The founders of Swiss Rockets AG are Dr. Vladimir Cmiljanovic, Dr. Natasa Cmiljanovic, Manuel Ebner, Dr. Thomas Sander and Dr. Thomas Staehelin. Vladimir Cmiljanovic is the CEO, a medicinal chemist, and an entrepreneur with more than 15 years of experience in cancer drug development. He is the founder of the Swiss biotech companies PIQUR AG, TargImmune AG, Swiss Rockets AG, Rocketvax AG and Torqur AG. With his sister Dr. Natasa Cmiljanovic, the Chief Scientific Officer of Swiss Rockets AG, he has developed cancer drugs at the University of Basel. He has also founded and managed several biotech companies.

Manuel Ebner is a Managing Director at Bank of America Merrill Lynch, Switzerland, and a strategic advisor to Swiss Rockets AG. Dr. Thomas Sander, one of the first employees of the biotech company Actelion, is a scientific advisor to Swiss Rockets AG. Dr. Thomas Staehelin, the co-founder of Swiss Rockets AG, is a member of the Executive Board and Chairman of several shareholder companies and foundations.

Members of the Board of Directors of Swiss Rockets AG are Dr. Vladimir Cmiljanovic (Chairman), Prof. Dr. Michael N. Hall, a renowned researcher and professor at the Center for Molecular Biosciences at the University of Basel, Dr. Natasa Cmiljanovic, a medicinal chemist and clinical scientist with experience in the development of cancer drugs, Dr. Thomas Ladner, a business lawyer, founder and co-founder of several successful start-ups and the World.Minds Foundation, André Debrunner, a financial expert and fund manager at Northern Trust Switzerland AG, and Christoph Brutschin, former Government Council of the Canton of Basel-Stadt and former Chair of the Canton’s Conference for economic affairs.