The PHH-1V vaccine against Covid-19 is developed by HIPRA, a company based in the Catalan region and the first round of trials will mainly test the safety and tolerability of the vaccine, as well as its immune response and efficacy, reports Xinhua news agency. 

The tests will be carried out on a group of volunteers aged between 18 and 39 years old who will be selected in the coming days, the Agency said on Wednesday. 

Spanish TV network RTVE reported that the study will see the volunteers being divided into groups, which will then receive different doses of the vaccine, with each volunteer receiving two injections 21 days apart. 

The HIPRA vaccine is based on recombinant proteins, which work together to produce an immune response against one of the proteins in the SARS-CoV-2 virus known as the "spike protein". 

This system is similar to that used in the Novavax and Sanofi COVID-19 vaccines, which are currently being evaluated by the Europeans Medicines Agency (EMA) with a view to their authorisation for use. 

The main difference between the Spanish vaccine and the other two is that the Spanish one uses proteins from two different variants of the virus and can also be stored at temperatures of between 2 and 8 degrees Celsius. 

If the clinical tests are completed successfully and according to plan, the company hopes to start production in October this year and launch the commercialisation of its vaccine before the end of the year, producing 400 million doses during 2022 and 1.2 billion doses by 2023.