Set vaccine efficacy via vaccinate_num()

[cmerenstein]

Feature: When allocating vaccines using the vaccinate_num() function, I would like to be able to manually set the efficacy of the vaccine on transmission, infection, death, etc. As far as I can tell, with this function I have to define a vaccine using the antibody amounts, but I'm not sure how to translate that into saying a vaccine is X percent effective at preventing infection/death/transmission.

Use Case: I am trying to simulate vaccine allocation during the spring of 2021. I am mostly interested in short term effects of the roll-out, and therefore many of the more advanced immunity related features of CovaSim (i.e. setting antibody levels and waning efficacy) aren't all that useful.

Also, I know I could use simple_vaccine() and set these parameters explicitly, but this function doesn't give the same control in terms of who gets vaccinated, since it doesn't take the "sequence" argument.

[cliffckerr]

Thanks @cmerenstein ! We'll see if we can address this in the next version of Covasim.