(44-20) 74 18 84 00 Fax (44-20) 74 18 84 16 E-mail: mail@emea. eu. int http: / /www. emea. eu. int  EMEA 2006 Reproduction and/ or distribution of this document is authorised for non commercial purposes only provided the EMEA is acknowledged ‘ immunogenicity’ of the vaccine (its ability to make the immune system respond to the viruses).