I've been seeing a lot of discussion around the dosage gaps recommended by government for the Astra/Oxford & Pfizer/BioNTech vaccines. My thoughts on the potential benefits & risks of such an approach, and the need for much greater transparency around these decisions. Thread.
The UK govt announced recently that both the Oxford & BioNTech vaccines would be now administered with a gap of between 4-12 weeks (so prioritise administration of first dose, given limited resources).
What is the basis of this?
The basis that's been discussed seems to be that
1) the first dose is likely to confer some degree of protection against disease, so better to roll this out as fast as possible, and
2) that for Oxford/Astra efficacy may be higher when the gap between doses is greater.
I discuss some of the technical details around the Oxford trial below for those interested in these. If you'd just like a summary of this, please skip to the summary tweet titled 'SUMMARY'.
What does published evidence show? The Astra/Oxford data are a bit messy because of protocol changes during the trial. This is because the trial was originally planned as a single dose trial, but a booster dose was added when developers realised that this would likely help.