We look at data from the current Delta outbreak in New Zealand.
We find that the likelihood of fully vaccinated to be hospitalised is less than 5% of the likelihood of unvaccinated being hospitalised.
We find that Covid cases in NZ are 3.5 times more likely to be unvaccinated than vaccinated.
We first note this modelling: Unvaccinated people are 25 times more likely to be hospitalised for Covid-19 – and about three times more likely to contract the virus – than those who’ve had both doses of the Pfizer shot. See:
We look at this table from the previous post (data from 5 January 2022 for the current Delta outbreak starting circa 16 August 2021). See:
Total unvaccinated (including under 12s):
4218 + 2719 = 6937
Fully vaccinated: 2007
6937 / 2007
= 3.5 (1 d.p.)
Therefore Covid cases in NZ are 3.5 times more likely to be unvaccinated than fully vaccinated.
From the last column in the table, the total percentage hospitalised that are unvaccinated (including under 12s) is
65.636 + 7.732 = 73.368
Therefore the percentage from the fully vaccinated is
7.045 / 73.368 ~ 9.6 %
The unvaccinated are 20% of the total population since the partially vaccinated are 80%. See:
Also the percentage vaccinated is four times the percentage unvaccinated (80% vs 20%).
The number of fully vaccinated cases is less than the number of partially vaccinated cases (2007 vs 2078). The percentage of fully vaccinated cases is just over 49% (2007/4085) of the total number of vaccinated cases.
Also the percentage fully vaccinated is obviously less than the percentage partially vaccinated (2 doses vs only one dose; 77% vs 80%; the fully vaccinated are just over 49% (77/157) of the total vaccinated).
The percentage vaccinated is four times the percentage unvaccinated (80% vs 20%).
Therefore the percentage fully vaccinated is around 49% of the 80% or 39.2%.
This is almost double the 20% unvaccinated.
Therefore we can expect that the probability of a fully vaccinated person being hospitalised is about half of the 9.6%. (4.8% or 1/21) of the probability for unvaccinated person.
The percentage is therefore less than 5%. i.e. less than 1/20.
The unvaccinated are at least 20 times more likely to be hospitalised than the fully vaccinated.