Culture‐Derived Parasites in Vaccination of Cattle against Tick‐Borne Diseases

Abstract

The major economically important tick‐borne diseases of cattle are theileriosis, babesiosis, anaplasmosis, and cowdriosis. Culture‐derived attenuated schizonts of Theileria annulata have proved to be safe for all types of cattle and they protect against tick‐borne theileriosis. T. parva was also successfully grown in vitro; however, inoculation of cattle with allogeneic schizont‐infected cells resulted in rejection and destruction of the parasites together with the host cells. The number of schizont‐infected cells needed for immunization is greater than for T. annulata theileriosis. Culture‐propagated Babesia bovis and B. bigemina were used for large scale vaccination in the field. An avirulent population of Babesia spp. was obtained by in vitro cloning; inoculation of cattle did not induce clinical babesiosis, but produced specific antibodies. Culture‐derived exoantigens of Babesia spp. proved to be completely safe for cattle, however, they conferred less protection than live parasites. Cell‐cultured Cowdria ruminantium was highly infective for susceptible animals but, attenuated in vitro, could offer a potential source for vaccination. Anaplasma marginale, successfully grown in tick cell culture, may be developed for vaccines. Factors that should be considered in the developing of vaccines against tick‐borne diseases include: the protective immune response to the pathogenic parasite developmental stages, virulence, immunological strain differences, and antigenic variations in cattle and in culture.

Genetic polymorphism of Babesia bovis merozoite surface antigens-2 (MSA-2) isolates from bovine blood and Rhipicephalus annulatus ticks in Israel

“…The culture-derived vaccine was developed by continuous in vitro cultivation and cloning (Shkap and Pipano, 2000). The blood samples from Gonen and Nir Oz cattle designated Gon and NOZ, were collected from adult beef cattle grazing in the north (Golan Heights) and in the south (Eshkol region) of Israel, respectively.…”

Emerging perspectives in the research of bovine babesiosis and anaplasmosis

“…The B. bovis attenuated parasites used in vaccines are derived by serial and rapid passage of a virulent strain among 20-30 splenectomized steers. In contrast, B. bigemina attenuation is usually performed by slow passages of a virulent strain in spleen-intact steers (Callow et al, 1979;Shkap and Pipano, 2000). However, in both cases, the parasite populations resulting from the serial passages generally have an attenuated phenotype when inoculated into spleen-intact 3-9 month-old steers.…”

“…Live vaccines have many drawbacks such as the requirement of a cold chain, a short shelf life, and the potential for the transmission of concurrent pathogens and for reversion to virulence (Shkap and Pipano, 2000;Fish et al, 2008). Because of the shortcomings, there is still the need for additional research on the development of alternative safer and better defined live or subunit vaccines.…”

Current Status of Veterinary Vaccines

“…The protective effect of this vaccine seems to be based on the antibody-dependent neutralization of a soluble parasite substance that causes hypotension and clinical disease, rather than acting through reducing parasitemia per se (156). This vaccine approach was also evaluated in cattle but did not confer sufficient protection (165).…”