One of the few places that publishes daily information on the infection rate in vaccinated and unvaccinated people is the ZOE Covid Symptom study. Above is today’s estimate for the U.K., based on the data submitted by users through the ZOE app, and it shows something very striking. While the infection rate in vaccinated people has been trending well below that in the unvaccinated for months, in the last two weeks the rate in the vaccinated has surged while that in the unvaccinated has plateaued.
We don’t know what is causing this. The vaccinated group is older than the unvaccinated group, which will skew its infection rate lower as older age groups have a lower infection rate anyway (see below). The currently slowing growth in the younger age groups and the increasing growth in the older, more vaccinated age groups is likely to be a reflection of the same underlying infection patterns as those in the vaccinated and unvaccinated groups.
One factor may be that younger people are now being vaccinated (see below), though equally infection rates have been rising fast in those aged 50-60, who have been vaccinated for some time.
It’s worth noting that the ZOE graph includes everyone who’s had at least one vaccine dose, not just the fully vaccinated. Nonetheless, the sharp rise among the vaccinated at the same time as infections in the unvaccinated plateau is certainly a striking trend, and may be further evidence that the vaccines do not prevent infection as well as many studies have suggested.