Dynamics of Specific Antibody Responses Induced in Mallards After Infection by or Immunization with Low Pathogenicity Avian Influenza Viruses

Abstract

Natural infections with different subtypes of low pathogenicity avian influenza viruses (LPAIVs) are very common in wild duck populations. Recent outbreaks of high pathogenicity avian influenza virus (HPAIV) H5N1 in Eurasian and African countries stimulated monitoring activities in aquatic wild bird populations. Surveillance mainly focused on virus detection. Only a few serologic investigations have been conducted so far, although such data may retrospectively elucidate epidemiologic patterns of different AIV subtypes in the populations under study. To better understand the immunologic and serologic reactions of mallards after infection with LPAIV, we investigated the AIV type- and subtype-specific antibody dynamics in mallards after different LPAIV infections by hemagglutination inhibition, competitive enzyme-linked immunosorbent assay, and western blot analysis, as appropriate. Four groups of mallard ducks were used: 1) naturally infected birds, 2) birds that were experimentally infected with LPAIV, 3) birds that were immunized with inactivated virus preparations, and 4) negative control birds. Ducks were monitored for up to 15 mo, and serum samples were investigated every 1-4 wk. It could be shown that infection with LPAIV in mallards can be traced serologically over prolonged periods of time.

Competition between influenza A virus subtypes through heterosubtypic immunity modulates re-infection and antibody dynamics in the mallard duck

“…Our results are in agreement with other studies in both ducks and gulls that reported partial to complete protection against re-infection depending on the viruses, time between infections, host species and age and detection method [10, 22, 23]. The long-term persistence of antibodies after natural infection, artificial challenge or vaccination has been reported in captive birds up to 6 to 9 months post-exposure [24–26] though it is not know which parameters (i.e. HI or MN titers) are correlated to protection.…”

Disease Dynamics and Bird Migration—Linking Mallards Anas platyrhynchos and Subtype Diversity of the Influenza A Virus in Time and Space

“…An alternative explanation for different patterns of subtype occurrence in early versus late autumn would be that immunity against certain subtypes will change the subtype composition over the season. In experimental studies, infected mallards show homosubtypic immunity (short-term [21], [40], as well as long-term [50]), and even heterosubtypic effects, where partial or complete immunity derived from the infection of a certain subtype may be active also against other subtypes [21], [40].…”

Identifying crucial gaps in our knowledge of the life-history of avian influenza viruses—an Australian perspective

“…Even basic knowledge, such as contact-rates between conspecifics and heterospecifics and the mechanisms of transmission (see Box 1) are lacking. How long previously infected birds remain immune from re-infection by homologous and heterologous AIV subtypes is likewise poorly known (Fereidouni et al 2010).…”

“…Unlike the surface proteins, these internal proteins have a highly conserved genetic sequence, which allows the detection of antibodies from birds infected with any influenza A virus (Suarez and Schultz-Cherry 2000). Antibody titre has been seen to increase rapidly as a result of re-infections, and is thought to be responsible for the decreased shedding period seen in re-infected individuals (Kida et al 1980;Fereidouni et al 2009Fereidouni et al , 2010Jourdain et al 2010). However, there is very little knowledge on how long these antibodies persist, with current estimates somewhere between a few months to a year (Nishiura et al 2009;Fereidouni et al 2010;Hoye et al 2010a).…”