Making avian influenza vaccines available, an industry point of view (IFAH).

Abstract

Vaccination against avian influenza (AI) has proved to be an efficient tool in the reduction of virus excretion and in increasing the threshold for infection. Vaccination in outbreaks, as part of a complete programme, has proved to be an essential component of control and eradication programmes. Avian influenza is a serious threat to public health. In contingency plans for outbreaks of highly pathogenic AI (HPAI), the option of emergency vaccination, using inactivated or recombinant vaccines, should be considered. The availability of suitable vaccines has to be ensured in 'peace time' in a contract for a vaccine or antigen bank. Unlike the human influenza vaccines, poultry AI vaccines have proved to provide protection against a wide range of strains within the same H-subtype. However, in case new H5 or H7 strains emerge in poultry, there is no regulatory guideline to support a swift reaction by the vaccine industry. Production of HPAI virus should take place in facilities with a Biosafety Level 3 (BSL3) to safeguard containment of virus and to prevent infection of manufacturing staff. Vaccine strains for inactivated vaccines should preferably be low pathogenicity AI (LPAI). In a new outbreak, it is essential to determine early which vaccine strain will provide protection against the field virus. Sequencing does not predict the protective capacity of vaccines. Challenge studies, providing essential information, take too much time and can be carried out only in BSL3 facilities. Serological matching of vaccine and field strains would provide a faster system. It is recommended that a matching system be developed and validated.