A dramatic plunge in positive coronavirus swab rates have been seen in the first 50,000 over 60’s vaccinated in Israel. Very encouraging data has been shared in several news outlets, including the Daily Mail, showing dramatic very early protection from the effects just one dose of the vaccine.

The graph is very dramatic, and shows that the risk for the population who had been vaccinated mirrors the entire over 60 population right up until 14 days. There is then a clear separation between the lines which begins two weeks after the first vaccination. This is crucial to understand as there is a risk of complacency one the needle has gone into your arm which would be very misplaced.

The risk of infection and hospitalisation both fell by approximately 60% by three weeks after the first dose had been given.

This approximate 60% risk reduction figure is calculated in a slightly unusual way as it is comparing the risk of vaccinated people to the risk of the whole population (which also included the vaccinated people). This will have had the effect of slightly reducing the risk seen in the upper graph (which might actually explain the very slight reduction seen even in the upper arm). But the cohort vaccinated early only made up around 10% of the entire population studied (480,000 people). So the real benefit may even be slightly better than that seen so far. It is also not clear how many of the people who tested positive were symptomatic. The data can be seen in a different way here:

If you have been vaccinated do not assume you are protected immediately!

All this is sure to reassure British scientists who have taken the potentially life-saving decision to role out the first dose of vaccines as quickly as possible, delaying the second.

Israel is rolling out the vaccine faster than any other country

Here you can see the impressive rate at which Israel has been rolling out the vaccine per head of their population. The also prioritised their elderly which is why the data is clear. It is encouraging to me that the UK is doing quite well in rolling out our vaccine, with the USA also actually doing rather well compare to most other developed countries. Todays data is a clear incentive to accelerate the process for all countries.

The myth that vaccinations had failed in Israel

There had been some confusion in recent days about the data coming out of Israel who currently lead the world in terms of the percentage of their population they have already vaccinated against COVID19.

Todays data shows how important it is to actually understand data before you make headlines about it . It is a very different message to that shown a few days an article by the Guardian which claimed that “only” a 30% reduction had been seen in infections. This failed to mention that this data was looking at very soon after the vaccine was given (before it had a chance to work) and that it is looking at swab positive rates in a population where I believe they are testing many or most people weekly. We do not expect the vaccines to have a 100% success rate in preventing asymptomatic disease. Indeed the clinical trial data suggested that there may be approximately a 30% drop in swab positive rates and a much higher drop in symptomatic disease, and at least in clinical trials a 100% prevention of severe disease requiring hospitalisation or leading to death. So in fact today’s data is even better than we would have hoped since it does look at positive swabs and not just symptoms though there is a notable reduction also in hospitalisations.

I originally saw this data in the Daily Mail which is not my usual soruce of scientific news, but it was also shared in a LinkedIn Post from KSM Research: