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An interesting discussion about the AstraZeneca – Oxford vaccine. Moderna and Pfizer/BioNTech were very clear with the protocol and with the reporting. I described the details of the statistical basis of the trials in The Conversation article. Moderna group even released a very detailed report on side effects.

In contrast, the Oxford trial seems to have been conducted in a less rigorous way and we are missing the data to analyse it in the same detail. The 62% to 90% efficacy switch with 1/2 dose at the first treatment will need more study; it has been reported that the “optimal” dose has only been given to 2,3oo people and there were issues with who received the “optimal dose”.

This just stresses how important it is to understand the statistical details behind the vaccine trials. None of the trials addressed long-term efficacy and safety, and the efficacy (and safety) in different age/vulnerability groups are still open.

Living with coronavirus vaccine

The Conversation UK, an online publisher of popular scientific articles, is organising a webinar on the subject of the coronavirus vaccine:


Strathclyde will be represented by my colleague, Dr Lynn Williams, and your humble correspondent. It should be both a fun and interesting experience.

Click here to register and you will be sent joining instructions before the event. The event is free to attend and you get an opportunity to ask questions!

Vaccine vs. natural immunity

Have just seen a Twitter post by US Senator Rand Paul (Kentucky):

Firstly, Senator should be congratulated on doing correct math and comparing numbers (not a common feature among politicians, see below). There is a bit of a problem that we do not know whether either vaccine or natural immunity is lasting (and whether the 200 reinfections are a valid estimate, or represent initial values in a bigger wave resulting from loss of immunity), but there is also a deeper issue with these calculations.

And this is safety:

Naturally acquired COVID-19 immunity comes with significant side effects. Assuming 1% infection fatality ratio (IFR) which is a currently accepted value, COVID-19 leads to 1 in 100 serious side effects. In my medicine leaflet, this is listed under Common side effects. If a vaccine led to 1% deaths, it would not pass the regulations.

Without prejudging the safety of Pfizer and Moderna vaccines when they are widely rolled out, the current status is that the level of serious side effects is less than 1 in 10,000 which is classed as Very rare side effects.

I am not saying the vaccine is completely safe – we do not know this at this stage – but it appears much safer than the natural immunity.

I wish Senator was honest and not only mathematically competent.

Another example from today’s Twitter shows somebody who is neither honest nor mathematically competent.

Sadly, 50,000 divided by 5,000,000 is not 0.1% but 1%. I wish politicians:

  1. Knew how to do mental math, or at least knew how to use a calculator
  2. When the mistake is shown to them, they could say sorry and delete the tweet.