Feedback on diphtheria/camps model

[pratikunterwegs]

This issue logs feedback from @ffinger on the diphtheria model model_diphtheria() based on Finger et al. 2019, and potential next steps for package development - thanks @ffinger! If there's anything I've missed or that you'd like to add just put it in the comments.

General

• The model would also be suitable for diseases targeted by routine vaccination such as measles or pertusis
• Not suitable for diseases with different transmission dynamics such as Ebola or cholera

Demographic stratification of contacts

• There is not always good evidence for whethr or how contacts vary by demographic group in a camp setting, but the option to model this would be good to have
  • Dev: Add social contacts functionality to the model, with a default assumption of homogeneous social contacts across demographic groups

Vaccination

• Reactive vaccination campaigns are often conducted in response to diphtheria outbreaks
  • Dev: The model should support the {epidemics} vaccination functionality via <vaccination> objects
• Reactive diphtheria vaccination campaigns may be conducted periodically every ±6 months, and may comprise of 1 - 3 doses, depending on dose availability;
  • Dev: Consider whether the intended use case covers a long-term simulation which would require implementing a repeated vaccination functionality (see also #227);
  • Dev: Consider whether more than one vaccination compartment/stratum needs to be implemented (as in Vacamole);
• Vaccination may only prevent symptomatic disease but may not prevent transmission
  • Dev: Consider whether the model needs more compartments ($I_s, I_{as}$ for symptomatic and asymptomatic), and how these can be linked to the hospitalisation compartment;

Population movements

• Modelling movements between camps in a metapopulation model may not be necessary for a scenario model, and it may be more appropriate to implement separate models for each camp;
• Population influxes into camps (see the population_change functionality) may differ in their vaccine coverage profiles, but there may not be good estimates for this
  • Dev: It is currently sufficient to assume that all individuals in an influx enter the susceptible compartment