Vaccination of birds other than chickens and turkeys against avian influenza

Abstract

Most avian influenza (AI) vaccination and field studies have focused on chickens and turkeys because of their high death rates and the large amounts of highly pathogenic avian influenza (HPAI) virus that they excrete into the environment when infected. Data on vaccination of other species against HPAI remain limited. An increasing number of studies have been conducted to test the efficacy of inactivated vaccines in ducks and geese since it became clear that these species are a source of HPAI H5N1. One problem is the varying susceptibility of waterfowl to H5N1 in general, and to different H5N1 clades in particular. This makes the extrapolation of protection results obtained for a particular waterfowl species against a particular viral strain very difficult. At present, the vaccine industry only produces and licenses products for chickens and turkeys. Since the market for other birds is small, it does not invest heavily in testing products in other species. Most information on vaccination in other birds comes from zoo vaccination, and consists solely of serological data. Whenever experimental challenge was performed in birds other than chickens and turkeys, vaccination using inactivated vaccines always protected against disease and mortality, provided the vaccine was sufficiently matched antigenically with the challenge virus. Inactivated vaccines induce good antibody titres in most species when applied twice and when body weight is taken into account. Until the advent of more specific waterfowl vaccines that can be used in day-old chicks, inactivated vaccines can be applied to protect not only chickens and turkeys but also ducks and other valuable and/or endangered bird species.

H5-based DNA constructs derived from selected highly pathogenic H5N1 avian influenza virus induce high levels of humoral antibodies in Muscovy ducks against low pathogenic viruses

“…Following vaccination with an inactivated H5N2 vaccine in free-range domestic ducks, sera were collected in flocks where unvaccinated sentinel birds had remained negative and were tested against the vaccinal antigen: HI titres ranged between 0 and 9 log 2 with a mean titre of 6 log 2 [28]. Other experimental studies have shown that vaccination against influenza in ducks with inactivated vaccines eventually requires higher antigen doses and multiple injections to be immunogenic and protective [29]. Depending on the type of vaccine used (inactivated or recombinant vector vaccine), experimental post-vaccination mean HI antibody titres against an antigen homologous to the vaccine usually remain low in Muscovy ducks, ranging from < 2 to 5.4 log 2 following a single injection [30-32].…”

The response of mute swans (Cygnus olor, Gm. 1789) to vaccination against avian influenza with an inactivated H5N2 vaccine

“…The vaccination strategy should be carried out only in combination with biosecurity measures [ 21 – 23 ]. In the EU, commercial inactivated AI vaccines were licensed for use only in chickens and Pekin ducks, but they were also shown to be effective in other bird species [ 24 – 26 ]. It should be noted that only individual species of wild birds kept in captivity can be considered for AI vaccination.…”

Insight into Alternative Approaches for Control of Avian Influenza in Poultry, with Emphasis on Highly Pathogenic H5N1

“…, ducks, geese, turkeys), zoo and/or exotic birds even within the same species ( i.e. , Muscovy vs. Pekin ducks) respond differently to vaccination which have not yet been fully investigated compared to chickens [35,36,37,38,39,40,41,42]. (9) Concomitant or prior infection with immunosuppressive pathogens or ingestion of mycotoxins can inhibit the immune response of AIV‑vaccinated birds [43,44,45,46].…”