1. Polio

Reproductive number of Polio is 6

Ro = 6

Generate sequence of numbers for fraction of population vaccinated from 0 to 1 with 0.1 interval.

fraction_vaccinated = seq (0, 1, 0.1)

Print fraction of population vaccinated.

cat ("Fraction of population vaccinated: ", fraction_vaccinated)
## Fraction of population vaccinated:  0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Compute effective reproductive number

Re = Ro * (1 - fraction_vaccinated)

Print effective reproductive number.

cat ("Effective reproductive number:", Re)
## Effective reproductive number: 6 5.4 4.8 4.2 3.6 3 2.4 1.8 1.2 0.6 0

Compute herd immunity threshold.

herd_immunity_threshold = 1 - (1/Ro)

Print herd immunity threshold.

cat ("herd immunity threshold = ", herd_immunity_threshold)
## herd immunity threshold =  0.8333333

Plot fraction of population vaccinated (versus) effective reproductive number.

subtitle = paste("Ro = ", Ro, ", Herd Immunity Threshold = ", round(herd_immunity_threshold, digits = 4) , sep="")

plot (fraction_vaccinated, Re, main = "Polio", sub = subtitle, xlab = "Fraction of population vaccinated", ylab = "Effective reproductive number (Re)")

Results and Discussion

Reproductive number of Polio among population is 6. The graph shows that if the fraction of population vaccinated increases, effective reproductive number will decreases. Herd immunity threshold is 83.33%; meaning that, at this level of vaccination coverage, effective reproductive number is 1 (Re = 1). When vaccination coverage is above 83.33%, the effective reproductive number is less than 1 (Re < 1); Thus, Polio will be eliminated at these higher levels of vaccination coverage.

Public health implications

Recommend Polio vaccination among the population at coverage levels of above 83.33%.