M. Pilar Muñoz

Evaluation of particulate acellular vaccines against Brucella ovis infection in rams

The attenuated Brucella melitensis Rev 1 vaccine, used against brucellosis infection, interferes with serological diagnosis tests, may induce abortions in pregnant animals, and may infect humans. In order to overcome these drawbacks, we developed acellular vaccines based on a Brucella ovis antigenic complex (HS) containing outer membrane proteins and R-LPS entrapped in poly(anhydride) conventional and mannosylated nanoparticles (NP-HS and MAN-NP-HS) or in poly(epsilon-caprolactone) microparticles (HS-PEC) as antigen delivery systems and immunoadjuvants. Brucellosis free rams were vaccinated subcutaneously with a single dose of particles containing 3mg of HS, and challenged 6 months thereafter. Protection was evaluated by clinical, bacteriological and serological examinations, in comparison with non-vaccinated control rams. HS-PEC vaccine induced protection (7 out of 13 animals were infected) equivalent to that induced by the reference Rev 1 vaccine (8/14). In contrast, animals immunized with NP-HS were not protected, showing similar results to that obtained in the control unvaccinated rams. Furthermore HS-PEC vaccine did not interfere against B. melitensis serodiagnostic tests. In summary, HS-PEC microparticles could be used as a safe and effective vaccine against brucellosis in rams.

Influenza vaccine coverage, influenza-associated morbidity and all-cause mortality in Catalonia (Spain)

The objective of this work was to study the behaviour of influenza with respect to morbidity and all-cause mortality in Catalonia, and their association with influenza vaccination coverage. The study was carried out over 13 influenza seasons, from epidemiological week 40 of 1994 to week 20 of 2007, and included confirmed cases of influenza and all-cause mortality. Two generalized linear models were fitted: influenza-associated morbidity was modelled by Poisson regression and all-cause mortality by negative binomial regression. The seasonal component was modelled with the periodic function formed by the sum of the sinus and cosines. Expected influenza mortality during periods of influenza virus circulation was estimated by Poisson regression and its confidence intervals using the Bootstrap approach. Vaccination coverage was associated with a reduction in influenza-associated morbidity (p<0.001), but not with a reduction in all-cause mortality (p=0.149). In the case of influenza-associated morbidity, an increase of 5% in vaccination coverage represented a reduction of 3% in the incidence rate of influenza. There was a positive association between influenza-associated morbidity and all-cause mortality. Excess mortality attributable to influenza epidemics was estimated as 34.4 (95% CI: 28.4-40.8) weekly deaths. In conclusion, all-cause mortality is a good indicator of influenza surveillance and vaccination coverage is associated with a reduction in influenza-associated morbidity but not with all-cause mortality.

Tuberculosis en Barcelona: modelo predictivo basado en series temporales

Adjusted segmented regression (piecewise regression) was applied to the series of new cases in the indigenous and immigrant populations of Barcelona. The evolution of TB differed radically; whereas in the indigenous population there was a downward trend, coinciding with the reduction in new of cases of AIDS, in immigrants there was an upward trend. The estimated number of new cases in 2009 was 168 (95% CI 109 227) in indigenous subjects and 227 (95% CI, 180 - 275) in immigrants.

Contagion between Markets During Financial Crises

In this work we investigate how a number of crises have affected most of the stock markets in the world. First, we apply Time Series Factors Analysis (TSFA) in order to reduce the dimensionality of the series under study and obtain a lower number of factors that can be related to regions. Then we use the dynamic conditional correlation (DCC) model to obtain the pair-wise correlations between regions. Finally, we analyse the effect of the different crisis on correlations. This approach allows us to detect contagion between markets during the most important crisis. Our results show evidence of a contagion effect between most regions.