The research project for the development of the ISPANVAC vaccine for the wild rabbit has been completed, whose work began in April 2004 and ended in November 2010, jointly, by the National Institute of Agricultural and Food Research and Technology (INIA) of the Ministry of Science and Innovation; the Biodiversity Foundation (FB) of the Ministry of the Environment, Rural and Marine Affairs; the Royal Spanish Hunting Federation (RFEC), through the Foundation for the Study and Defense of Hunting (FEDENCA), and the SYVA S.A. Laboratories.

The trials confirmed the efficacy and safety of this recombinant vaccine against myxomatosis and viral haemorrhage (to date, there is no vaccine on the market that immunises rabbits against these two diseases in a single vaccine dose), although the confirmation of the absence of transmissibility between vaccinated specimens alters the initial hypothesis that with few doses applied, the vaccine would spread to a greater number of specimens.

The current project was born driven by the need to give continuity to a study promoted by the HIPRA laboratories, the results of which had to be contrasted with new tests that have been undertaken within the framework of this research project. This work, which has been carried out since 2004 by the four aforementioned parties, has sought to comply with a series of requirements imposed by the European Medicines Agency for its authorisation.

Although the vaccine is not ultimately transmitted from vaccinated to unvaccinated individuals, it is proven to be safe for each of the vaccinated rabbits and for rabbit predators as well as on pregnant rabbits. The vaccine strain does not become more virulent after five passes (virulence reversion).

One of the difficulties faced by the project is the great variability of factors that can influence the transmissibility capacity of the vaccine virus (climatic and geographical conditions, presence of vectors, population density, health status and other characteristics of rabbits, as well as other unknown factors). These are the same factors that make myxomatosis outbreaks seasonal and appear only at certain times of the year, when the right conditions are met, and that possibly explain the differences in the results obtained in the 2004 experiments on the Air Island.

With these results, the Monitoring Committee of the project decided to consult the Spanish Agency for Medicines and Health Products on the benefit/risk ratio for the ISPANVAC vaccine in order to know the feasibility of a favourable response by the European Medicines Agency and, therefore, to be able to evaluate the continuity of the work to prepare the authorisation dossier to the European Medicines Agency (EMEA). The Agency replied with a negative report on 1 April 2011 and therefore this phase of experimentation has been concluded.