Pulse vaccination strategy

Where T= time units is a constant fraction p of susceptible subjects vaccinated in a relatively short time. This yields the differential equations for the susceptible and vaccinated subjects as

${\displaystyle {\frac {dS}{dt}}=\mu N-\mu S-\beta {\frac {I}{N}}S,S(nT^{+})=(1-p)S(nT^{-})n=0,1,2,\dots }$

${\displaystyle {\frac {dV}{dt}}=-\mu V,V(nT^{+})=V(nT^{-})+pS(nT^{-})n=0,1,2,\dots }$

Further, by setting I = 0, one obtains that the dynamics of the susceptible subjects is given by:[3]

${\displaystyle S^{*}(t)=1-{\frac {p}{1-(1-p)E^{-\mu T}}}E^{-\mu MOD(t,T)}}$

and that the eradication condition is:[4]

${\displaystyle R_{0}\int _{0}^{T}{S^{*}(t)dt}<1}$

• Critical community size
• Epidemic model
• Herd immunity
• Pulse Polio
• Ring vaccination
• Vaccine-naive

Wikimedia Commons has media related to Vaccinations.

• Immunisation Immunisation schedule for children in the UK. Published by the UK Department of Health.
• CDC.gov - 'National Immunization Program: leading the way to healthy lives', US Centers for Disease Control (CDC information on vaccinations)
• CDC.gov - Vaccines timeline
• History of Vaccines Medical education site from the College of Physicians of Philadelphia, the oldest medical professional society in the US
• Images of vaccine-preventable diseases