January 28, 2021

expert comment about how the UK reports on 1st & 2nd doses of mRNA vaccine in the four nations

A comment from Professor Sheila Bird on how the UK reports on first and second doses of mRNA vaccine in the 4 nations.

Prof Sheila Bird, Formerly Programme Leader, MRC Biostatistics Unit, University of Cambridge, said:

“On 31 December 2020, the UK’s four Chief Medical Officers (CMOs) wrote to doctors to advise that maximizing the number of citizens in Priority Groups 1-4 receiving their 1^st dose of COVID vaccine by mid-February 2021 was in the interest of the public health.

“Doctors were advised: those in Priority Group 1+2 (care home residents and staff, healthcare and social care workers, citizens aged 80+ years) who already had their 1st dose of Pfizer/BioNTech mRNA vaccine should have their pre-scheduled 2^nd dose deferred from 21 days after the 1^st (as trialled; and as originally authorized by MHRA) to a maximum dose-interval of 12 weeks.

“What actually happened is that doctors exercised clinical discretion very differently in the 4 nations, see https://coronavirus.data.gov.uk/details/vaccinations;  https://beta.isdscotland.org/find-publications-and-data/population-health/covid-19/covid-19-statistical-report/; & Table.

“First notice: since the Oxford/AstraZeneca COVID vaccine was not rolled out in the UK until 4^th January 2021, ALL COVID vaccine 1^st doses administered in the weeks prior to 4^th January 2021 are Pfizer/BioNTech doses.

“Secondly, ALL COVID vaccine 2^nd doses administered in the UK prior to 1 February 2021 have to be Pfizer/BioNTech doses.  The explanation for this is that the authorized dose-interval for the Oxford/AstraZeneca vaccine is 4 weeks to 12 weeks.  Moreover, the CMOs recommended the maximal interval of 12 weeks.  What do the data in my Table reveal about mRNA 2^nd doses?

1. England, alone, has failed to report the number of Pfizer/BioNTech 1^st doses administered during the critical first week (8-13 December 2020) of the vaccine’s roll-out.

2. Only Scotland report vaccine-type for 1^st doses administered after 3^rd January 2021.

3. Hence, comparison between the 4 nations in terms of 1^st Pfizer/BioNTech doses per million of population is limited to the 3-week period of 14 December to 3 January, when 1^st doses per million of population ranged from 21 610 and 19 610 pe million for England and Northern Ireland through 17 680 and 13 270 for Scotland and Wales.

4. Colour-coding in Table links 1^st dose recipients (red) and, three weeks later, the percentage of those recipient who received their 2^nd dose (red) on the original [1/22 day] schedule.

5. Doctors in Northern Ireland, followed by those in England, exercised substantial clinical discretion in giving pre-scheduled 2^nd mRNA doses as booked (i.e. 3 weeks after 1^st dose).

6. Northern Ireland excepted, relatively few 2^nd doses were administered in the week ending 3 January 2021.

7. Hence, those who received their 2^nd doses during 4-10 January may include citizens whose 1^st dose was administered during 8-13 December – but that count is missing for England!

8. The more robust comparator between nations – in doctors’ exercising clinical discretion – is therefore the inferred percentage of citizens whose 1^st dose was administered during 21-27 December (blue) who received their 2^nd dose (blue) in the week ending 17 January 2021.

9. By this reckoning, clinical discretion in administering 2^nd mRNA dose on the originally authorized schedule [days 1/22] ran highly at 59% in Northern Ireland; was 14% in England; but only 3% in Scotland; and 1% in Wales.

10. Instead of having to use logic to make deductions, as above, the 4 nations’ reporting on their roll-out of COVID-19 vaccines (soon to be three) should follow Scotland’s reporting standard.  Incident SARS-CoV-2 should already be linked-in and added to enable historical week-on-week comparison for those who did/did not receive their 2^nd mRNA vaccine 3-weeks after the 1^st.”

Table: First [second] doses of Pfizer/BioNTech vaccine doses administered per week – by nation – % percentage of 1^st dose citizens in Priority Groups 1+2 who got their 2^nd dose 3 weeks after their 1^st

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.