Herd Immunity

September was not as bad as it could have been and not as bad as expected. The number of new cases per week for the UK has levelled out, as has the death rate. The mortality remains around 0.5% so 1 in 200 people who have tested positive have died.

The expected rise due to the schools going back did not happen, and hopefully the students going back to UNI will not have too much and effect either.

Hospital admissions are going down too, and one area where the number of cases is low is London – where there is a very high population density! So what is happening?

Perhaps it is to do with herd immunity! London did have a great number of cases in the first and second wave, and whilst it is known that you can get infected again, perhaps the chances are considerably less.

In the UK as a whole we have recorded over 7.5 million cases. But there probably have been more. In my first post I said that the mortality rate was about 4%. In March I re-examined this and observed that the mortality wave has improving, probably due to the effect of the vaccination program. Currently the mortality rate seems to be about 0.5%, but perhaps in the previous wave the mortality was not as high as I had estimated.

As an approximation we can treat the time before say, 1st March as having a mortality rate of about 1.5%, and after that 0.5%

Deaths up to 1st MarchMortalityEstimated real number of cases
122,8491.5%8,189,933
Deaths after 1st march
13,3190.5%2,663,800

So the actual number of case would be around 11 million (or around 16% of the entire population), with hotspots in what have been the worst effected areas – like London. Couple this partial immunity with the partial immunity from the vaccines (45 million people, or 66% double jabbed), and we may well be seeing the beginnings of herd immunity.

This may also help explain the huge spike in cases in Cornwall due to the G7 conference and the boardmasters festival as hoards of outsiders descended on an area, which until then, had seen far fewer cases than the rest of the UK, and at a time when the number of people double jabbed was far lower than now. Basically the Cornish people had very little immunity due to previous infections, and little immunity due to vaccinations, especially in the younger people. Cornwall cases ramped up rapidly but have now dropped back to similar levels to the rest of the UK.

We are still at dangerous levels for vulnerable people. Roughly 1 in 300 people report a new case of the virus every week. We can expect this number to fluctuate, and probably get worse in the colder weather, but in the long term the trend should be down.

It looks like herd immunity will be the UK’s only way out of this mess.

And that is a long term prospect.


Septembers data

Scotland’s cases are coming down after a huge spike qs the schools went back. England’s schools went back two weeks later but there has not been anything like the spike that Scotland saw. England’s new case rate seems relatively stable at around 3500 per million per day (or 350 per 100,00)
Scotland’s death rate is peaking due to the spike in cases 2-3 weeks ago. England’s death rate remains around 12 per million of population per week.
Vaccinations per week are now under half a million. In late May the NHS were administering over 4 million doses per week.
Population over 12 waiting for first jab
Population over 12 waiting for second jab

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