Validation of an Attenuated Live Vaccine Against Babesiosis in Native Cattle in an Endemic Area

Abstract

The objective of this study was to evaluate in native cattle the use of an in vitro derived attenuated live vaccine (Babesia bovis-Babesia bigemina). Three commercial farms located in a tropical region in Chiapas State, Mexico were included. For each ranch, 40 animals were selected as negative to Babesia spp. by using an immunofluorescent antibody test (IFAT) and PCR. Animals were distributed in four groups with 10 animals each: (i) <9 months, (ii) 9-18, (iii) 18-36 and (iv) >36 months old. From each group, two subgroups were formed with five animals each; one subgroup was vaccinated and the other served as control without vaccination. Monitoring and sampling were carried out initially at vaccination (day 0), at day 7 and then every 4 weeks for 12 months. During the study rectal temperature ( degrees C), packed cell volume (Ht %) and percentage of erythrocytes parasitized were registered, furthermore IFAT and PCR were performed. Prevalence rate at the beginning of the study was 83% by IFAT. During the survey, 26 non-vaccinated of the 120 selected animals (43%) showed clinical symptoms of babesiosis, confirmed by stained smears versus only four (6.6%) of the vaccinated ones. All Babesia-affected animals required specific treatment. Vaccinated cattle showed titres of up to 1 : 1840 and 1 : 1027 for B. bovis and B. bigemina, respectively by IFAT. Protection conferred by vaccination was about 93%. We propose that this vaccine should not only be used in cattle coming from babesiosis free zones, but also in native cattle kept in hyperendemic areas.

Co-immunization of cattle with a vaccine against babesiosis and Lactobacillus casei increases specific IgG1 levels to Babesia bovis and B. bigemina

“…In spite of having anti-Babesia antibodies, the bovines living in endemic areas of babesiosis are susceptible to reinfections and calves born in these areas can show clinical signs of babesiosis also [6]. Animals that showed anti-Babesia antibodies were used; however, it has been pointed out that a persistent, detectable antibody titre is not a prerequisite for a protective immune response.…”

“…The increased levels of IgG1 stimulated by L. casei along with the vaccine vs. babesiosis may be an advantage for the transference of passive immunity to B. bovis and B. bigemina from the cow to the calf. On the basis of the results and the observation that calves younger than 9 months of age and living in endemic areas of babesiosis are susceptible to the disease [6], the simultaneous vaccination of cows against babesiosis with the vaccine and L. casei would be desirable because it would promote high levels of IgG1 anti-Babesia antibodies which are the most important IgG sub-class of antibody transmitted passively through colostrum and milk to their offspring [37][38][39][40][41].…”

“…In Mexico, 75% of the 23, 316,000 cattle [4] are at risk of acquiring babesiosis [5]. It is important to point out that, besides adults, cases of clinical babesiosis have been documented in calves younger than 9 months of age in endemic areas of this disease [6]. To curb the huge economic losses caused by bovine babesiosis, live vaccines made of attenuated parasites were developed [7].…”

Genetic conservation of potentially immunogenic proteins among Brazilian isolates of Babesia bovis

“…Vaccination against B. bovis is a widespread method used to diminish the impact of clinical disease (Nari et al, 1979;Kessler et al, 1987;Callow et al, 1997;De Vos and Bock, 2000;Ojeda et al, 2010). However, the available vaccines are based on bovine blood infected with live attenuated organisms (Nari et al, 1979;Kessler et al, 1987).…”

In silico and phylogenetic analyses of partial BbRAP-1, BbCP2, BbSBP-4 and BbβTUB gene sequences of Babesia bovis isolates from cattle in South Africa

“…This follows that the cattle which recover from primary acute infection remain persistently infected and serve as reservoirs for parasite transmission to other animals [ 4 ]. Nevertheless, it is worth noting that the available vaccines are based on bovine blood infected with live attenuated strains of the parasite [ 6 , 7 ]. Although these vaccines confer protective immunity, the major limitation associated with the use of attenuated vaccines relate to the possible transmission of other blood-borne pathogens [ 6 ].…”