The first clinical trial results from a Danish coronavirus vaccine demonstrate high effect and no serious side effects. Researchers from the Department of Biomedicine at Aarhus University are examining the vaccine's potential for preventing infection.

2021.08.26 | Line Rønn

Monday’s announcement by Danish company AdaptVac of the first data from a new coronavirus vaccine caught a lot of attention in Denmark and abroad. The vaccine shows itself to be very promising – it is both safe and effective, and proof of the effectiveness of the vaccine has been provided by researchers from Aarhus University.

"We can see that the antiviral response of the test subjects is ten times stronger than if they had had the Covid-19 disease. The vaccinated test subjects also achieve even higher levels of virus-neutralizing antibodies than those reported for the use of the already approved vaccines from Pfizer-Biontech and Moderna," says Professor Søren Riis Paludan, who calls the early trials "really promising."

The antibody levels are a marker of how well the vaccine protects, and this is exactly the data that Søren Riis Paludan’s laboratory at the Department of Biomedicine delivers.

The Danish vaccine – which still goes under the not so catchy name of ABNCoV2 – demonstrates good effect against the different variants of the coronavirus – including the Delta and Beta variants that are presently the most dominant both in Denmark and globally.

In addition, it appears that the vaccine does not have any serious side effects.

Why are additional vaccines so vital?

The Danish company AdaptVac has developed and patented the technology behind the new vaccine. AdaptVac approached Aarhus University for virological expertise and has collaborated with Søren Paludan's laboratory since March 2020 in an alliance supported by the Carlsberg Foundation and others.

In July 2020, the pharmaceutical giant Bavarian Nordic purchased the rights to the coronavirus. This means that Bavarian Nordic is financing further clinical development and is responsible for selling the vaccine worldwide. The interest in the project shows that new coronavirus vaccines are still interesting, even though a number of already approved vaccines are in production around the world.

"More vaccines are needed, because the coronavirus is here to stay. The first challenge was to vaccinate the population. The second challenge will be to maintain immunity throughout the foreseeable future," says Søren Riis Paludan.

"We hope that ABNCoV2 can potentially be used together with the already approved vaccines when revaccination is needed," he explains.

"Our aim is for it to be a booster vaccine that you get once a year, for example. Like we see with influenza vaccines," says Søren Riis Paludan.

Other proposals for the use of new vaccines include low-income countries, where only a tiny proportion of the population has been vaccinated.

The Danish vaccine candidate is based on a different technology than the two approved mRNA vaccines. It consists of a protein structure with coronavirus protein connected on top, and in several areas it is comparable to protein-based vaccines such as the widespread injection against the human papillomavirus (HPV).

Airlines would not transport viruses to Aarhus

At the beginning of 2020, there was a huge race to develop vaccines, and Danish initiatives were also begun.

As early as March 2020, Aarhus University was granted permission by the authorities to work with coronavirus and all the viral variants from around the globe.

"We’ve got a great deal of virological expertise, so our task was to establish methods to test the effectiveness of vaccines in a manageable way. But we’ve had to stay up-to-date with all the new coronavirus variants and import them from the country where there was an outbreak of the new variant. This often meant countries on the verge of chaos such as South Africa or Brazil," says Søren Riis Paludan.

The researchers from Aarhus typically contacted colleagues in other countries who had published a pre-print article about new variants.

There was a lot of dialogue – also with the airlines and courier companies, whose initial position was that they would not bring a package with a new coronavirus variant onboard. The result was expensive transport solutions every time a small test tube carefully packed in dry ice had to be transported to Aarhus.

But it was worth the cost, says Postdoc Manja Idorn, who has been responsible for the testing of the vaccine candidate at the Department of Biomedicine.

"We’ve created a trial setup that the virus can grow in. If there are no antibodies in the environment, the virus will kill the cells, and here we can therefore measure whether an sample contains antibodies that can block the viral infection," she explains.

After animal experimentation on mice and monkeys, the first patient was given the Danish vaccine in March 2021 in a Phase I trial financed with DKK 20 million from the EU and DKK 13 million from the Carlsberg Foundation. Since then, a total of 45 healthy patients have received two doses of the vaccine at Radhoud University Medical Centre in the Netherlands.

According to Bavarian Nordic, Phase II trials are expected to start in August at two clinical centres in Germany. The plan is for Aarhus University to also contribute to this phase.

This will be followed by the large-scale Phase III trial, which for the Pfizer and Moderna vaccines involved 40-45,000 test subjects.

If everything goes according to plan, the vaccine can be on the market at the beginning of 2022, and if this is indeed the case, it will be celebrated in the laboratory at the Department of Biomedicine, says Søren Riis Paludan, even though the laboratory’s contribution only constitutes a small part of an enormous research, development and coordination collaboration: 

"In our daily work we’re mostly nerds who’re immersed in basic research and have very specialised knowledge. But sometimes we can make a direct contribution to solving some of the very biggest problems. When society needs expertise in precisely this field, only people like us actually have that expertise and can make it available at short notice. It’s an example of how strong basic research is a condition for the development of new medicines and vaccines, and that the unbiased collaboration between basic research and the industry is beneficial for society," he says.

 Who is behind the vaccine?

• AdaptVac, a joint venture company established by ExpreS2ion Biotechnologies and NextGen Vaccines – a spin-out from the University of Copenhagen. AdaptVac is a member of the vaccine consortium PREVENT-nCoV, which includes several European universities. The consortium has received a grant from the EU Framework Programme for Research and Innovation (Horizon 2020) to bring the development of the vaccine from AdaptVac to clinical trials.
• Radboud University Medical Center, Holland
• Bavarian Nordic
• Aarhus University
• University of Copenhagen
• AGC Biologics, USA
• BioConnection, Holland

Contact

Professor Søren Riis Paludan
Aarhus University, Department of Biomedicine
Mobile: (+45) 2899 2066 
Email: srp@biomed.au.dk