Bovine Anaplasmosis: Will there ever be an almighty effective vaccine?

Abstract

Bovine anaplasmosis is a tick-borne bacterial disease with a worldwide distribution and the cause of severe economic losses in the livestock industry in many countries, including México. In the present work, we first review the elements of the immune response of the bovine, which allows ameliorating the clinical signs while eliminating the majority of the blood forms and generating an immunologic memory such that future confrontations with the pathogen will not end in disease. On the other hand, many vaccine candidates have been evaluated for the control of bovine anaplasmosis yet without no commercial worldwide effective vaccine. Lastly, the diversity of the pathogen and how this diversity has impaired the many efforts to control the disease are reviewed.

Bovine Anaplasmosis: Diagnosis, Treatment and Control Strategies

“…Infected erythrocytes are recognized by macrophages in reticular tissues and vascular sinusoids present in the red pulp of the spleen. The optimal capture activity by macrophages occurs until high concentrations of infected erythrocytes are reached (Rodríguez et al 2008;Salinas-Estrella et al 2022b). Non-specific phagocytosis has been demonstrated in the spleen and may explain splenomegaly present in the infections (Palmer et al 1999).…”

“…Strains of A. marginale of naturally low virulence have also been tested (Bock et al 2003;Rodríguez-Camarillo et al 2008) with promising results, yet not a single one of these options has reached the commercial use, because of the ever-present risk of transmission of blood associated pathogens with implicit disastrous results (Rogers et al 1988). Inactivated vaccines tested so far while inducing solid immunity to homologous challenge, are yet to induce the same level of protection against heterologous strains (Salinas-Estrella et al 2022b). Proteins that in their native form have induce solid immunity have failed to induce immunity as recombinant counterparts (Sarli et al 2020) and even in some cases, animals inoculated with them showed worse clinical syndromes (Ducken et al 2015).…”

“…Molecular diversity and antigenic variability have proven to be an obstacle to the induction of protective immunity against all strains studied so far. Although studies have been conducted with immunorelevant proteins, these proteins may not be conserved in all strains, so that robust protection may be induced against some strains but not others (Quiroz-Castañeda et al 2016;Salinas-Estrella et al 2022b). Native, recombinant proteins and peptides have been tested as immunogens, with results that range from full protection against homologous challenge to no protection or even a worse clinical syndrome against heterologous strains (Ducken et al 2015;Curtis et al 2020;Sarli et al 2020).…”

“…Early diagnosis allows a better control and reduction of economic losses (Railey and Marsh, 2021). Even though there is not a universal vaccine commercially available, but there are several approaches in curse around the world to develop effective immunogens (Salinas-Estrella et al 2022b) and many work still needs to do in order to generate better control strategies that contribute to improve bovine, human and environmental health.…”

Dynamic nesting of Anaplasma marginale in the microbial communities of Rhipicephalus microplus

“…Anaplasma marginale is a bacterium that causes bovine anaplasmosis, a disease characterized by anemia, fever, and other clinical symptoms in cattle (Salinas-Estrella et al, 2022). This disease can lead to significant economic losses due to decreased productivity, increased veterinary costs, and even livestock mortality (Rodríguez et al, 2009;Salinas-Estrella et al, 2022).…”