Comparison of the Safety and Efficacy of Different Atrophic Rhinitis Vaccines

The principal characteristic of Atrophic Rhinitis (AR) is a reduced growth rate due to the atrophy of the nasal turbinates caused by the dermonecrotoxin (DNT) released by Pasteurella multocida toxigenica (1). Sows vaccinated against AR produce elevated levels of antibodies which are passed to their offspring via the colostrum. The antibody titer against DNT is directly correlated with the degree of atrophy of the nasal turbinates (2) and thus a reduction in growth rate (3). Some trials have shown that vaccines differ in their ability to induce homogeneous titers in sows (4). The purpose of this study was to evaluate and compare the safety and efficacy of the principal vaccines available in Spain.

The trial was conducted on a farm with 3,000 sows in northwestSpainoperating a two-phase production system. AR-negative replacement sows were acquired from unrelated units, but the herd nevertheless suffered from atrophic rhinitis, and the sows were frequently vaccinated against the disease. Fifty individually identified primiparous sows, not already vaccinated against AR, were randomly allocated to one of 5 groups of 10 sows each. Prior to farrowing, four of the groups were vaccinated with a different commercially available product according to each manufacturer’s instructions. The fifth group was maintained as an unvaccinated control.

The groups, identified by the product used, were: Vaccine A (mineral oil adjuvant); Vaccine B (mineral oil adjuvant); Vaccine C (Ginseng adjuvant), Porcilis AR-T DF and Control. Blood samples were collected from the sows at the time of the first vaccine dose and 2 weeks after the second dose. The sera were assessed for antibody levels against Pasteurella multicida (PMT) with the TDN-Seroneutralization test, and against Bordetella bronchiseptica (Bb) with the Blobel Micro-agglutinacion test. Safety was assessed by taking the sows’ body temperatures at 8 and 24 hours post-vaccination, from observations of any adverse systemic and/or local reactions. Efficacy was evaluated from antibody titers obtained in each group. The Linear Method (GLM: program SPSS 15.0) was used for the statistical analysis.

Safety: there was one abortion in the Vaccine A group, and two sows each of the Vaccine A and Vaccine C groups stopped eating for two days following vaccination. At 24 hours post-vaccination, only Vaccine A (2 sows) and C (1 sow) groups contained sows with a temperature >40ºC (Graph 1) 

Graph 1. Body temperature following vaccination 

Efficacy: the antibody levels induced post-vaccination are summarised in Table 1.

Table 1: Mean antibody titers per group (Log₂)

Porcilis AR-T DF was shown to be safe, and induced high titers against both antigens. It performed significantly better than Vaccines B and C (and the controls) with respect to Bb, and significantly better than Vaccine A (and the controls) for PMT. Elevated antibody levels against both antigens helped in producing less atrophy in the nasal turbinates and better growth rates.

1. Van Diemen PM, 1994, Am J. Vet Res,55:49-541. 2. Sorensen V, et al., 1990, 11^th IPVS,57

3.NielsenJ.P.,1991, Ca J Vet Res.

4. Martens M, Eggen A, 2010, 21^st IPVS, 380