Title: Torremorell M. 1995;4:139-143. Vaccination against S suis
Headings: Vaccination against
Streptococcus suis
:
Effect on nursery mortality

Field study
Vaccination against Streptococcus suis:
Effect on nursery mortality
Montserrat Torremorell, DVM; Carlos Pijoan, DVM, PhD; Emilio Trigo, DVM, PhD
Summary
Material and methods
Herd history and clinical evaluation
Field vaccine trial
Statistical analysis
Posttrial vaccination protocols
Results
Discussion
Implications
References

Content: In May 1996, the producer decided to adopt a sow vaccination protocol, which was less expensive, less time consuming, and easier to implement. Sows were vaccinated IM with the commercial bacterin at approximately days 77 and 98 of gestation. Piglets were followed during the nursery stage, and mortality rates were used to evaluate the effectiveness of this protocol. This protocol was still in use at the time of this report. Results
Pigs that received the experimental autogenous vaccine tended to have lower morbidity/mortality ( P <.1) than pigs in the other groups  ( Figure 2 ). Mortality in the nonvaccinated group was 5.5 % and morbidity was 13%; both were lower than the 17% mortality observed in groups of weaned pigs in the herd previous to the on-farm vaccine trial. Mortality was nonexistent among pigs vaccinated with the commercial vaccine during the first 4 weeks of the experiment, but increased to 10% during the last 2 weeks of the trial. In comparison, mortality rate was 14% for a nearly identical group of pigs that was not vaccinated and that received identical diet and management and was weaned within 1 week of the pigs included in the trial. These pigs were housed in an adjacent room to those included in the trial, and shared the same airspace.