Fig 1.
Effect of vaccine deployment on the reproductive number, according to strategy and variant.
Epidemic reproduction number as a function of vaccinated fraction of population and vaccine efficiency for each of the four presented strategies, assuming a base reproduction number of R0 = 2.5 for the COVID-19 Alpha variant and R0 = 3 for Delta. Each data point (mean and standard error bar) is based on 20 duplicate simulations.
Table 1.
Effect of vaccine deployment on R, the reproductive number, in response to vaccination strategies for COVID-19 Alpha and Delta variants.
Epidemic reproduction number as a function of vaccinated fraction of population and vaccine efficiency for each of the four presented strategies, assuming a base reproduction number of R0 = 2.5 for the COVID-19 Alpha variant and R0 = 3 for the Delta variant. Each data point (mean and standard error) is based on 20 simulations.
Fig 2.
Impact of different vaccination strategies on the reproductive number R according to varying pre-vaccination R0.
R0 is adjusted by varying the amount of contact in the random layer of the model, while other layers (schools, workplaces, households) are kept constant. Dashed lines indicate the fraction of population which needs to be vaccinated in order to achieve herd immunity R < 1 depending on R0 for an unvaccinated population. Herd immunity thresholds are also shown for random and age-dependent vaccination for comparison purposes. Grey denotes infeasible vaccination fractions (>80%) for the 18+ strategy. The depicted R values are averages of 20 duplicate simulations for each data point.
Fig 3.
Herd immunity thresholds according to R0 and choice of strategy.
Fraction of population requiring vaccination in order to reach herd immunity (R < 1) according to each strategy and R0 for an unvaccinated population. Each data point and corresponding errorbar represent the mean R and standard deviation of 20 duplicate simulations, respectively.
Table 2.
Herd immunity thresholds F* in response to R0 and choice of strategy according to strain.
Fraction of population requiring vaccination in order to reach herd immunity (R < 1) according to each strategy and R0 for an unvaccinated population. Each data point (mean R and standard error) is based on 20 simulations.