Javier Ochoa Repáraz defended his dissertation at the School of Science at the University of Navarra, where he defended his thesis the development an acellular vaccine against Salmonella Enteritidis. This is a global pandemic considered the most significant zoonosis—a disease or infection in animals that can be transmitted to humans under natural conditions. It is estimated that the incidence of acute salmonellosis worldwide exceeds one billion cases per year and causes three million deaths.

The project developed by Javier Ochoa, which has obtained the maximum grade, has focused on the study of a new vaccine based on the encapsulation of components of the cell envelope of Salmonella Enteritidis. The vaccine has demonstrated its efficacy in mice infected with this disease, and is currently being used in experimental farms of the Hipra laboratories in Gerona, business involved in the control of pathogens in poultry.

Poultry and poultry products are recognized as the most important source of Salmonella Enteritidis infection in humans. "Both the World Health Organization (WHO) and the European Union have established guidelines to eradicate infection in poultry, as the benefits to the human population would be obvious. It is widely accepted that the most internship measure is vaccination, as it is the easiest to apply and the least expensive, but so far all the measures applied are showing a leave efficacy", says Javier Ochoa.

In Spain, Salmonella Enteritidis is the bacterium that causes 85% of foodborne gastroenteritis and considerable economic losses in both the food and health sectors. In the specific case of Navarra, during 2003, 343 cases of foodborne toxiinfluenza were reported, of which 79 were aggregated in the form of 14 outbreaks, 12 of them due to Salmonella.