Last night MHRA chief executive Dr June Raine said the regulator had issued new advice to vaccination centres 'following two reports of anaphylaxis and one report of a possible allergic reaction following immunisation'.
Under the new guidance clinicians have been told that anyone receiving the vaccine needs to 'be monitored for 15 minutes after vaccination, with a longer observation period when indicated after clinical assessment'.
The updated advice comes after the MHRA warned on Wednesday that the Pfizer/BioNTech vaccine should not be administered to patients with a history of allergic reactions.
The requirement for practices to observe patients for 15 minutes could throw some primary care network (PCN) plans into disarray - after practices were told last month that a 15-minute observation period would not be necessary and that patients could be told simply not to drive for that period.
GP-led designated sites will now have to ensure they have the physical space to allow patients to remain on-site for 15 minutes, while socially distanced - potentially slowing the rate at which vaccinations can be delivered significantly.
This time pressure is critical - because each location will be expected to deliver 975 doses of the vaccine within 3.5 days.
Commenting on the updated guidance, Dr Raine said: 'We convened an expert group of the Commission on Human Medicines (CHM), attended by experts in allergy and clinical immunology, to robustly review these reports to consider any possible mitigation on the rare risk of anaphylaxis.
'Any person with a history of anaphylaxis to a vaccine, medicine or food should not receive the Pfizer/BioNTech vaccine. A second dose should not be given to anyone who has experienced anaphylaxis following administration of the first dose of this vaccine.'
All vaccination sites are expected to have a protocol for managing anaphylaxis and 'an anaphylaxis pack must always be available whenever the Pfizer/BioNTech vaccine is given'. Health professionals managing vaccination sites should be trained to recognise an anaphylactic reaction and know how to resuscitate a patient experiencing one.
Meanwhile, NHS England has also issued guidance on how GPs leading the vaccination programme can escalate concerns or access rapid advice as the first primary care sites prepare to administer vaccines from next week.
The guidance forms part of the standard operating procedure for the designated sites in primary care – the full operating procedure is expected to be published imminently.
It says that any serious incidents, such as adverse events, should be 'escalated urgently and as a priority' to regional vaccination operations centres. The regional centres will then involve a clinical advice response service or escalate the matter to a national level.
It adds that those involved in responding to these fast-tracked incidents will be required to act within an hour of receiving the request.
NHS England said that it expects 'most incidents and enquiries will be resolved at a regional level'. GPs needing advice or other support will also be able to contact the clinical advice response service directly.
The guidance sets out four levels of 'clinical escalation triggers' for incidents that could cause a 'limited', 'moderate', 'significant' or 'critical' impact to the vaccination programme.
Issues deemed of 'critical impact' are those which have serious implications for 'patients and vulnerable populations'. This category would also include scenarios that have 'life-threatening or life-changing impact on patients and/or ethical implications for clinicians' as well as issues that could affect the vacciantion programme on a national level.
Some 280 designated primary care sites are due to be up and running next week, receiving their first batches of the Pfizer/BioNTech vaccine on either 14 or 15 December. The sites will be expected to being vaccinating patients the day after the delivery. The sites will initially focus on patients in the over-80 cohort who are able to attend for a vaccination.
Dr Raine said: '[Patients] can be completely confident that [the Pfizer] vaccine has met the MHRA’s robust standards of safety, quality and effectiveness. The safety data has also been critically assessed by the government’s independent advisory body, the Commission on Human Medicines. No vaccine would be approved unless it meets these stringent standards – on that you can be sure.
'We have in place a robust and proactive safety monitoring strategy for COVID-19 vaccines which allows for rapid, real-time safety monitoring at population level. The fact that these incidents were picked up and reviewed shows that to be the case.'