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expert reaction to media reports on US vaccine roll out

There have been reports in the US that President elect Joe Biden plans to release nearly all available vaccine doses once he takes office in an attempt to speed up delivery, a break with the Trump administrations strategy of holding back stock for second dose.


Professor Robert Read, Professor of Infectious Diseases at the University of Southampton, and a member of  the UK Joint Committee for Vaccination and Immunisation (JCVI), said:

“In the UK we have prioritised getting the first dose out to as many people as we can, amongst the vulnerable cohorts such as the elderly and those with co-morbidities. We calculate this move will maximise the reductions in hospitalisation and death which has to be our current focus. It is biologically plausible that delay (not cancellation!) of the second dose will not leave recipients undefended. It is likely that natural exposure to virus in the interregnum between first and a delayed second dose will simply result in natural boosting of immunity, rather than difficult disease. It is also plausible that a delayed second dose may even strengthen the long term benefits of the vaccine.”


Prof Stephen Evans, Professor of Pharmacoepidemiology, London School of Hygiene & Tropical Medicine, said:

“The original Pfizer/BioNTech trials for the vaccine allowed for a window of 19-42 days for the gap to a second dose. It seems this window is the primary reason for the WHO recommendation to definitely allow the second dose at up to six weeks after the first, since that was included in the trial data, though this has not always been made clear in either documentation or comments. There were 7.1% of trial participants, excluded from the results, who received the second dose outside the window or not at all. We have not been given efficacy estimates for them.

[WHO statement -]

“WHO also say “Countries should ensure that any such programme adjustments to dose intervals do not affect the likelihood of receiving the second dose.”

“The UK advice is that a delay up to 12 weeks is acceptable but do not suggest no second dose is necessary

“The Moderna vaccine was intended to have the second dose one month after the first, but again there was some variation in the day it was received.

“In both the UK and the US there are very large numbers of people infected with the virus and it is spreading very rapidly. These are unprecedented times.

“It is absolutely vital that recipients of the vaccine realise that, especially in the first 14 days or so they have NO protection against Covid by the vaccine and must continue to use caution by distancing and mask-wearing. Getting the vaccine is not a licence to  ignore the virus. Even after 14 days, the distancing etc should continue, since even with two doses, there is no 100% guarantee of protection. Eventually, we would expect the effect of vaccinating many people and with adherence to lockdown measures and distancing, that the numbers of people infected will fall, but that is months away.”


Prof Adam FinnProfessor of Paediatrics at the University of Bristol, said:

“In the current crisis facing the USA, the UK and many other countries with rapidly rising rates of COVID-19 infection, hospitals running out of space, medical and nursing staff falling ill and becoming exhausted and death rates accelerating, there’s a need for strategic planning. A dose of vaccine sitting in a freezer waiting for 3 weeks to pass is not helping but it would be if it were in someone’s arm. The chances that the 90% efficacy observed from 14 days after one dose of the Pfizer vaccine will wane away rapidly over subsequent weeks is remote. The additional protection provided by the second dose given at 3 weeks is small and far smaller than the protection that same dose can provide to another unimmunised person. In normal times we would obtain more evidence to modify dose schedules than we have right now but these are not normal times and we soon will have that information to guide us. Meantime we need to take a strategic approach and lend our second doses, temporarily, to our colleagues and neighbours, knowing we could be saving their lives.”



eg New York Times: Biden plans to release nearly all available vaccine doses in an attempt to speed delivery.



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