A comment from Professor Sheila Bird on the latest NHS COVID-19 vaccination statistics in England, for the week ending Sunday 3 January 2021.
Prof Sheila Bird, Formerly Programme Leader, MRC Biostatistics Unit, University of Cambridge, said:
“Whether 2nd dose of Pfizer mRNA vaccine was received appears age-dependent. As currently reported, only around 17% of those aged 16-79 years who received their 1st mRNA dose during 8 to 13 December received the 2nd as pre-scheduled: 21 days later. Over 700,000 others immunized during 8 to 27 December 2020 had their pre-scheduled 2nd mRNA dose deferred.
“The 1st doses of vaccine against COVID-19, if received in December 2020, were mainly of the novel Pfizer/BioNTech mRNA vaccine. The alternative, differently-principled Oxford/AstraZeneca vaccine was not authorized by Medicines and Healthcare products Regulatory Agency until 30 December 2020.
“Today’s statistical release and its forerunner published on 31 December 2020 give information by vaccination-date on 1st doses (also 2nd doses) of immunization against COVID-19 for two age-groups: 16-79 years and 80+ plus years. The majority of the younger age-group who received their 1st dose in December 2020 will be health and social care workers.
“Second doses were administered by 3 January 2021 for 5.2% of those aged 16-79 years who were reported to have received their 1st dose during 8 to 27 December. However, only those who received their 1st dose during 8th to 13th December 2020 (first six days out of the 20 days from 8 to 27 December, at most 30% (78 500 to nearest 100), would have been pre-scheduled to receive their 2nd dose on or before 3 January 2021.
“Those heady initial six days may, of course, account for far fewer than 30% of 1st doses during 8-27 December. Hence, I surmise that more than 17% of 16-79 year olds (13 567/78 500) mainly health and social care workers, who received their 1st Pfizer/BioNTech mRNA vaccine during 8 to 13 December 2020 would have received their 2nd dose, on-schedule, 21 days after the first. The percentage could be as high as one-third (13 567/40 000). Soon, we should be told the exact figures.
“Going forward, official statistics should please update weekly each row of the table below so that any calculated difference does not have to be caveated as mine do.
“In addition, of course, next week’s official statistics need to differentiate between the vaccines administered: Pfizer/BioNTech mRNA vaccine versus Oxford/AstraZeneca vaccine so that we can understand how these two vaccines are being deployed. As currently reported, over 1 million first doses of the mRNA vaccine were administered on/before 3 January 2021, 40% of them to persons under 80 years of age. As currently reported, the proportion of 2nd doses administered to those aged 80+ years who received their 1st dose during 8 to 27 December appears to have been substantially lower (1.2%) than for those aged 16-79 years (5.2%).
“Finally, my attribution – that most of those aged 16-79 years will have been health and social care workers – would be more apt if those aged 16-69 years were reported separately from 70-79 year olds.”
All our previous output on this subject can be seen at this weblink: