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The MRC Biostatistics Unit at the University of Cambridge have released their latest nowcast and forecast of COVID-19.
Prof Sheila Bird, Formerly Programme Leader, MRC Biostatistics Unit, University of Cambridge, said:
“The latest report by the MRC Biostatistics Unit/ Public Health England team of de Angelis and Birrell explains their but not our access to: (A) weekly immunization counts for England by region & age-group & whether 2nd dose was received.
“The report says: “The model now accounts for the ongoing immunisation programme, stratifying the population of people still susceptible to infection with the virus according to their immunisation status (unimmunised/1 dose/2 doses). We use data on the daily proportions of the population getting immunised to inform this splitting of the population, assuming that it takes three weeks for vaccine-derived immunity to develop.
These data are derived from the National Immunisation Management Service (NIMS). They include all COVID-19 immunisations administered at hospital hubs, local immunisation service sites such as GP practices, and dedicated immunisation centres.”
“The modellers assume that it takes 3 weeks for vaccine-derived immunity to develop but don’t disclose: i) the level of vaccine-effectiveness that has been assumed or estimated (with uncertainty); ii) whether and by how much vaccine-effectiveness has been assumed to differ by vaccine-type if a single-dose only has been administered; and iii) by how much vaccine-effectiveness of the Pfizer/BioNTech vaccine has been assumed, or estimated, to improve if the 2nd dose has been duly administered.
“Second doses of the Oxford/AstraZeneca vaccine are unlikely to have been administered in January 2021 because 1st doses were only offered from 4 January 2021.
“Vaccine-efficacy in the published randomized controlled trials (RCTs) has been estimated on the basis of reduction in COVID-19 cases after the second dose had been administered on the intended 1/22 day schedule (Pfizer/BioNTech); or 4-12 weeks after the 1st dose (Oxford/AstraZeneca). From these RCTs, it is not proven whether iv) the reduction in COVID-related hospitalizations for vaccine recipients follows directly from reduction in the number of COVID-19 cases or whether there is a vaccine-bonus in terms of lower hospitalization-rate per 100 COVID-19 cases in those vaccinated versus in those unvaccinated. Today’s report does not address itself to that question.
“In the interest of transparency, I appeal to the modelling team to publish the data they rely on: weekly immunization counts for England by region & age-group & whether 2nd dose was received together with more information on four other key aspects of their modelling of immunization against SARS-CoV-2, see i) to iv) above.”
https://www.mrc-bsu.cam.ac.uk/nowcasting-and-forecasting-12th-february-2021/
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
Declared interests
Prof Sheila Bird: “SMB is a former programme leader at MRC Biostatistics Unit but has not been involved in the innovative modelling work reported above.”