The first group of Dutch volunteers will start testing a vaccine against coronavirus next month, a spokesman for pharmaceuticals firm Janssen Nederland in Leiden told broadcaster NOS on Friday.

The selection of volunteers for the trials will start next week, the spokesman said. In total, 550 people in the Netherlands, Spain and Germany will take part in the trials. Of them, 135 will be at three different locations in the Netherlands.

Janssen, part of the giant Johnson & Johnson pharmaceuticals group, has already begun trials of the vaccine in Belgium and the US, where it is quicker to get permission for human testing.

The study currently underway involves giving participants two vaccinations, eight weeks apart. ‘In September we will look at giving less of the vaccine and if the interval can be made shorter,’ research leader Hanneke Schuitemaker told television programme Nieuwsuur earlier this month.

The European Commission plans to buy between 200 million and 400 million doses of the vaccine if it proves to be a success. This is likely to be next spring at the earliest.