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expert reaction to government’s aim to have offered the first COVID-19 vaccine dose to everyone in the four top priority groups by mid-February

Several journalists have asked us about the government’s vaccination timeline, so here are some comments from scientists.


Comments sent out on Thursday 7 January 2021:

Dr Zoltán Kis, Research Associate at the Future Vaccine Manufacturing Hub, Imperial College London, said:

“Vaccine manufacturing consists of two key stages: (1) the production of the active ingredient (aka. drug substance), (2) filling the drug substance into vials (aka. fill-to-finish).  Throughout each stage, thorough quality monitoring and testing is performed, and everything must be traceable.

“The Oxford/AstraZeneca vaccine drug substance is produced using living cells and each production batch (of ≈13 million doses) takes approximately one month to complete.  The Pfizer/BioNTech vaccine is produced using a simpler biochemical reaction and each production batch (of up to 5 million doses) is completed in approximately 2 days.  This does not include all the time required for quality testing.

“Vaccine manufacturing delays can arise as a result of:

– Transitioning from the phase of developing the production process to mass production, since these are new production processes that produce a new product.

– Quality testing issues.  For example; if the produced material does not meet the specifications the batch is discarded; some tests are time-consuming (testing that the vaccine is sterile takes 2 weeks) and; there is a limited number of qualified personnel to perform testing / sign the batch release assays.

– Limited drug substance production capacity as there were no dedicated facilities for Covid-19 vaccine production, so additional time was required for facilities to be repurposed (e.g. for the Oxford/AstraZeneca vaccine) and for development of new production lines (for mRNA vaccines such as Pfizer/BioNTech).  There is also a limited number of qualified personnel to operate these facilities.

– Fill-to-finish can be an overall production bottleneck since these types of facilities are shared by all the vaccines (and other products) and there is a limited capacity globally.  If additional vaccines gain regulatory approval and if the drug substance of these vaccines is stockpiled during clinical trials, the demand for fill-to-finish will further increase.

“If any of these steps are or do become hurdles it would be expected that they could be resolved within weeks and there will be a steady supply of vaccines.”


Comments sent out on Tuesday 5 January 2021:

Sandra Gidley, President of the Royal Pharmaceutical Society, said:

“The Government’s ambitious vaccination programme could be accelerated by resourcing pharmacies to become places where the public can receive the Oxford vaccine.

“Community pharmacists already provide flu and travel vaccinations.  Through pharmacies, the NHS has a ready-made workforce of skilled vaccinators who should have the opportunity to play their part to speed up delivery of the jab to priority groups.

“As trusted healthcare professionals, pharmacists can also help build confidence in the vaccine and increase its uptake.  Pharmacies have been open throughout the pandemic, doing a fantastic job under huge pressure, supplying medicines and healthcare advice.  They could provide easy, local access for patients to the Oxford vaccine and we are working with Government and the NHS to help make this happen.”


Prof Nilay Shah, Head of Department of Chemical Engineering, Imperial College London, said:

“Our analysis indicates that at steady-state it would be possible, with a great deal of co-ordination of manufacturing, logistics, rapid training of vaccination administration personnel, co-operation of patients, it should be possible to reach daily vaccination levels of 300,000 to 500,000 doses per day.  Having multiple sources of vaccines will help with volume of material but of course adds a bit more complexity in the operations management (although having a vaccine which only requires standard refrigeration helps).  At this stage it appears we are still in the ramp-up phase so we have not reached these levels yet.  These levels are several times higher than those achieved in peak influenza vaccination but in principle are achievable with additional resources and effective co-ordination.

“If we take the top four groups; this would be very approximately 10m people.  Assuming that we will go for a prime and boost vaccination strategy even if the gap may be longer, that implies 20m vaccinations.  At 400,000 doses per day, assuming we move to 7 days a week operation, that is 50 days which would get us to mid-Feb (for 100% coverage).  It’s an ambitious target and needs everything to click every day.  But we should aim for it and give it focussed attention from everyone in the system.  If the aim is for the first dose for the top four priority groups by mid-February, then we would need to hit 200,000 doses a day, again this is achievable but everything needs to go right every single day.”



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



Declared interests

Dr Zoltán Kis: “No conflict of interest to declare.”

Sandra Gidley: “Sandra Gidley is RPS President and also on occasion works a locum community pharmacist.”

None others received.

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