TY - JOUR
T1 - Impact of imperfect Mycobacterium avium subsp. paratuberculosis vaccines in dairy herds
T2 - A mathematical modeling approach
AU - Lu, Zhao
AU - Schukken, Ynte H.
AU - Smith, Rebecca L.
AU - Mitchell, Rebecca M.
AU - Gröhn, Yrjö T.
PY - 2013/2/1
Y1 - 2013/2/1
N2 - The objective of this study was to investigate the potential impacts of imperfect Mycobacterium avium subsp. paratuberculosis (MAP) vaccines on the dynamics of MAP infection in US dairy herds using a mathematical modeling approach. Vaccine-based control programs have been implemented to reduce the prevalence of MAP infection in some dairy herds; however, MAP vaccines are imperfect. Vaccines can provide partial protection for susceptible calves, reduce the infectiousness of animals shedding MAP, lengthen the latent period of infected animals, slow the progression from low shedding to high shedding in infectious animals, and reduce clinical disease. To quantitatively study the impacts of imperfect MAP vaccines, we developed a deterministic multi-group vaccination model and performed global sensitivity analyses. Our results explain why MAP vaccination might have a beneficial, negligible, or detrimental effect in the reduction of prevalence and show that vaccines that are beneficial to individual animals may not be useful for a herd-level control plan. The study suggests that high efficacy vaccines that are aimed at reducing the susceptibility of the host are the most effective in controlling MAP transmission. This work indicates that MAP vaccination should be integrated into a comprehensive control program that includes test-and-cull intervention and improved calf rearing management.
AB - The objective of this study was to investigate the potential impacts of imperfect Mycobacterium avium subsp. paratuberculosis (MAP) vaccines on the dynamics of MAP infection in US dairy herds using a mathematical modeling approach. Vaccine-based control programs have been implemented to reduce the prevalence of MAP infection in some dairy herds; however, MAP vaccines are imperfect. Vaccines can provide partial protection for susceptible calves, reduce the infectiousness of animals shedding MAP, lengthen the latent period of infected animals, slow the progression from low shedding to high shedding in infectious animals, and reduce clinical disease. To quantitatively study the impacts of imperfect MAP vaccines, we developed a deterministic multi-group vaccination model and performed global sensitivity analyses. Our results explain why MAP vaccination might have a beneficial, negligible, or detrimental effect in the reduction of prevalence and show that vaccines that are beneficial to individual animals may not be useful for a herd-level control plan. The study suggests that high efficacy vaccines that are aimed at reducing the susceptibility of the host are the most effective in controlling MAP transmission. This work indicates that MAP vaccination should be integrated into a comprehensive control program that includes test-and-cull intervention and improved calf rearing management.
KW - Dairy cattle
KW - Intervention
KW - MAP vaccination
KW - Paratuberculosis
KW - Simulation study
UR - http://www.scopus.com/inward/record.url?scp=84871659437&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84871659437&partnerID=8YFLogxK
U2 - 10.1016/j.prevetmed.2012.08.001
DO - 10.1016/j.prevetmed.2012.08.001
M3 - Article
C2 - 22921715
AN - SCOPUS:84871659437
VL - 108
SP - 148
EP - 158
JO - Preventive Veterinary Medicine
JF - Preventive Veterinary Medicine
SN - 0167-5877
IS - 2-3
ER -