-
Indeed. Even a partially effective vaccine has a massive effect on transmission rates. The maths is really quite simple. The smallpox vaccine wasn't 100% effective. Still didn't stop it being used to wholly eradicate smallpox.
Brommers-
smallpox vaccine wasn't 100% effective. Still didn't stop it being used to wholly eradicate smallpox.
By a similarly startling mechanism, starting a media campaign to put lids on water tanks and empty stagnant ponds managed to completely eradicate Malaria in in the UK in n the 1950s.
It just got the R rate down just low enough in the mosquito population.
-
Slightly off topic but I thought this recent Graun article on how they eradicated smallpox was really interesting
Tl;dr they used a tracing strategy and vaccinated all the contacts of each case to cut off the spread
mashton
charliem
But that becomes material if it means everyone infects half the number of people.
If R is 1.5 for example, and you start with 100 people with the virus, after 5 rounds you'd have 10*(1.5^5) = 75.9 infections.
With a 50% effective vaccine then that 1.5 I'd have thought becomes 0.75, so after 5 rounds the 10 people with the virus is 2
(I'm sure I've vastly simplified things, but a number that doesn't look too spectacular from the point of view of one person can actually be significant when applied to an exponential spread across a population)
Edit: the above assumes the entire population have received the vaccine, which is unrealistic. But principle is still there