Fig. 1
We extend the model from [18] to include a 24-stage vaccinated compartment, denoted by Z. Other compartments are susceptible (S), exposed (E), asymptomatic (A), infected and symptomatic but not hospitalized (I), hospitalized in acute stage of infection (HA), in critical care (acute stage) (CA), on mechanical ventilation (V), in critical care recovering phase (CR), hospitalized and recovering (HR), recovered (R), recovered from hospitalization (RHOSP). Green arrows show progression after an individual is vaccinated; dashed arrows indicate death. Exposed and asymptomatic individuals who are vaccinated receive no benefit from the vaccine and progress on their normal infection/disease course. We assume vaccines are not given to individuals with past confirmed infection. However, if no serological test is performed before vaccinating, it is possible that individuals in exposed (E), asymptomatic (A), and recovered (R) classes will have an equal chance of receiving the vaccine as truly susceptible individuals. Re-infection is possible as shown by arrows going from recovered R and RHOSP back to susceptible compartment S. Vaccinees in the Z class are not fully protected from infection since we allow waning of vaccine-induced immunity over time; infection of vaccinated individuals is shows with the dashed arrows from Z to E