Abstract:
Individuals vary in their potential to acquire and transmit infections, but this fact is
currently underexploited in disease control strategies. We trialled a trait-based vaccination strategy
to reduce tuberculosis in free-living meerkats by targeting high-contact meerkats (socially dominant
individuals) in one study arm, and high-susceptibility individuals (young subordinates) in a second
arm. We monitored infection within vaccinated groups over two years comparing the results with
untreated control groups. Being a member of a high-contact group had a protective effect on
individuals’ survival times (Hazard Ratio = 0.5, 95% Confidence Interval, CI: 0.29–0.88, p = 0.02)
compared to control groups. Over the study, odds of testing positive for tuberculosis increased
more than five-fold in control groups (Odds Ratio = 5.40, 95% CI = 0.94–30.98, p = 0.058); however,
no increases were observed in either of the treatment arms. Targeted disease control approaches,
such as the one described in this study, allow for reduced numbers of interventions. Here, traitbased vaccination was associated with reduced infection rates and thus has the potential to offer
more efficient alternatives to traditional mass-vaccination policies. Such improvements in efficiency
warrant further study and could make infectious disease control more practically achievable in both
animal (particularly wildlife) and human populations
Description:
SUPPLEMENTARY MATERIALS : FIGURE S1: Clinical cases of tuberculosis at the
KMP from 2014-2016, FIGURE S2: Group Changes throughout the study, FIGURE S3: Scatterplot of
scaled Schoenfeld residuals for the multivariable model of survival time to death, TABLE S1: Treatment
set composition at commencement of the study, TABLE S2: Survival analysis for time to a positive test
in 221 wild meerkats.