Oral vaccination of foxes and raccoon dogs against rabies with the 3rd generation oral rabies virus vaccine, SPBN GASGAS, in Finland

Ad Vos,Ferenc Kovacs,Tiina Nokireki,Marja Isomursu,Tuija Gadd

doi:10.1186/s13028-021-00605-y

Abstract

BackgroundTo prevent re-emergence of wildlife-mediated rabies in Finland, oral rabies vaccine baits are distributed every year during autumn in southern Finland in a vaccination zone bordering Russia. Recently, Finland introduced a 3rd generation oral rabies virus vaccine bait. By analysing bait uptake and seroconversion in red foxes and raccoon dogs, the field efficacy of this new vaccine strain, SPBN GASGAS, was compared with the originally used highly efficacious 1st generation vaccine SAD B19.ResultsOverall, 74.6% and 53.9% of the animals submitted from the vaccination area after the campaigns (2017–2019) tested positive for the presence of the bait marker and anti-rabiesvirus antibodies, respectively. No significant difference was observed between years, species and vaccine.ConclusionsThe field performance of the highly attenuated 3rd generation oral rabies vaccine, SPBN GASGAS, in terms of bait uptake and seroconversion was similar to the 1st generation vaccine, SAD B19, and therefore offers a suitable alternative.

Highlights

To prevent re-emergence of wildlife-mediated rabies in Finland, oral rabies vaccine baits are distributed every year during autumn in southern Finland in a vaccination zone bordering Russia
After applying the omission criteria described above, data from 407 control animals were available for analysis: 314 (77.1%) raccoon dogs and 93 red foxes (22.9%)
74.6% and 53.9% of the animals tested positive for the presence of the TC bait marker and antibodies against rabies virus, respectively (Tables 2, 3). 23.5% (71/226) of the animals showed evidence of bait consumption but did not have antibodies against rabies virus and 2.3% (7/76) of the animals had detectable levels of antibodies but no evidence of bait uptake (Table 4)

Summary

Introduction

To prevent re-emergence of wildlife-mediated rabies in Finland, oral rabies vaccine baits are distributed every year during autumn in southern Finland in a vaccination zone bordering Russia. Most cases were not observed in the known European reservoir species, the red fox (Vulpes vulpes), but predominantly in raccoon dogs (Nyctereutes procyonoides) [1]. This invasive species was first observed in Finland in the 1930s and after an initial phase of establishment its population increased greatly from the end of the 1960s onwards [2, 3]. Vos et al Acta Vet Scand (2021) 63:40 compare the field performance of the highly attenuated 3rd generation vaccine used since 2018 with the highly efficacious 1st generation vaccine during the previous campaign in 2017 as both vaccines are filled in the same type of sachet and subsequently incorporated in an identical fish product bait matrix The results of this comparison are presented in this study

Methods

Results

Conclusion