Table 3

Summary of the A/H1N1pdm Monte Carlo Maximum Likelihood (MCML) calibrations and best parameter estimates.

MCML and interventions1,2

Baseline SFO

Reference SFO

Pre-exposure immunity SFO

Social distancing in Mexico, April 24-May 10, 2009

Traffic reduction after April 25, 2009

Pre-exposure immunity

Vaccinations campaigns (data-driven)



Antiviral treatment (hypothetical scenario)


Pre-vaccination (hypothetical scenario)


MCML estimates3

Minimal seasonal rescaling factor, αmin4


(0.60 - 0.70)


(0.60 - 0.70)


(0.65 - 0.75)

Reference reproduction number in the Tropics, R05

1.75 (1.64 - 1.88)

1.75 (1.64 - 1.88)

1.8 (1.69 - 1.91)

1The '✓' symbol indicates the components considered in each stochastic forecast output (SFO) set and hence also in the calibration.

2The + symbol indicates the data-driven interventions and/or hypothetical scenarios considered in addition to each SFO set.

3Each MCML calibration and the corresponding set of best estimates was used to generate the stochastic forecast output datasets consisting of an ensemble of possible epidemic evolutions defining a median, mean, and reference range for epidemic observables.

4The αmin interval is the best-fit range within the minimal resolution allowed by the Monte Carlo sampling.

5For R0, we report the 95% confidence interval (in square brackets).

Tizzoni et al. BMC Medicine 2012 10:165   doi:10.1186/1741-7015-10-165

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