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Covid vaccine 15-minute observation period lifted temporarily

by Sofia Lind
15 December 2021

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The requirement for patients to stay for a 15-minute observation after mRNA Covid vaccination can be lifted on a temporary basis during the ‘Omicron emergency response’, the UK medicines regulator has said.

NHS England said in an operational update that the 15-minute wait can be waived from Thursday this week.

MHRA chief executive Dr June Raine said that ‘in light of the rapid spread of the new Omicron variant and the proven effectiveness of booster doses against Omicron, the 15-minute observation period following mRNA vaccines (Pfizer and Moderna) can be waived during the emergency response to the Omicron variant’.

The advice includes first and second vaccine doses as well as boosters.

The 15-minute observation period after vaccination ‘will remain in place for the small number of people who may have previously suffered anaphylaxis or other allergic reactions to a food, insect sting and most medicines or vaccines,’ Dr Raine said.

The MHRA decision was made because ‘anaphylaxis and other severe allergic reactions are very rare side effects’ and, ‘during this time when the Omicron variant is spreading rapidly, the benefits of vaccinating as many people as possible, which will be gained from waiving the 15-minute wait, far outweigh the very small risks of anaphylaxis’, she added.

MHRA will continue to ‘closely monitor’ UK and international data and urges anyone who suspects they have experienced a Covid vaccine side effect to report via the Yellow Card scheme.

‘Anyone who experiences symptoms of an allergic reaction such as difficulty breathing, rapid heartbeat or faintness should seek urgent medical attention,’ Dr Raine added.

The Commission on Human Medicines said the decision to ‘temporarily waive’ the ‘ post-mRNA observation period in specific circumstances’ was based on review of available Yellow Card data on anaphylaxis after the primary course and after boosters.

Commission chair Professor Sir Munir Pirmohamed said: ‘The data show that anaphylaxis and other severe allergic reactions are an extremely rare side effect with the Covid-19 vaccine.

‘Swift action is needed to tackle the rapid increase in cases of the Omicron variant of COVID-19 and the increasing risk to the public and healthcare services. This temporary measure will assist in the major task of vaccinating the nation ahead of the end of the year.’

The decision follows a recommendation from all of the UK’s chief medical officers this afternoon, who all agreed that ‘in the light of the very considerable need to speed up vaccination and boosting in response to Omicron variant, the 15-minute wait for some mRNA Covid-19 vaccines should be suspended’.

They highlighted as basis for their decision:

  • The fact Omicron is ‘spreading extremely rapidly, with a doubling time of 2 to 3 days’;
  • Yellow Card data which showed two anaphylactic fatalities in the UK following mRNA Covid vaccination;
  • NHS England modelling which suggested capacity of the vaccination programme is slowed down by 23% by the 15-minute observation requirement – leading to 500,000 people not getting vaccinated ‘during the initial period’.

The CMOs said: ‘Even allowing for the relatively crude initial calculations here, the absolute number of people put at risk because they cannot get vaccinated due to the 15-minute wait (in the high tens of thousands or higher) is much greater than the more precisely calculated number who get anaphylaxis.

‘Since the mortality rate for COVID-19 is non-trivial (although not yet calculated for Omicron) the probability of harm through delay is, in the view of the CMOs substantially in excess of the probability of benefit from maintaining 15-minute waits under the current situation.’

It follows BMA England’s GP Committee lobbying the MHRA for the removal of the requirement to observe patients for 15 minutes after vaccination with the Pfizer Covid jab.

The observation period was introduced in the first week of the vaccine rollout, following news that two healthcare professionals that were vaccinated on the first day with the Pfizer vaccine suffered an allergic reaction.

It does not apply to the Oxford/AstraZeneca vaccine, but GPs giving patients the Moderna jab must also observe them for at least 15 minutes.

Key points from the Covid-19 vaccine benefit-risk expert working group analysis on booster vaccination

a) Anaphylaxis following mRNA COVID-19 vaccination is a very rare but a potentially life-threatening event.

b) The EWG has previously stated that occurrence of anaphylaxis, where the first 2 doses of the same vaccine have been previously administered with no allergic reaction, would be extremely unlikely and agreed that the 15-minute observation time can be waived for homologous boosters (where the booster is the same vaccine as the first 2 doses) where no allergic reaction occurred on the first 2 doses.

c) The overall reporting rate of anaphylaxis with booster doses (0.26 per 100,000) was below that of reporting for the first 2 doses, with Moderna (1.47 per 100,000) and Pfizer (1.23 per 100,000). There had been 28 reports of anaphylaxis events with Pfizer booster doses (12 on a homologous i.e. Pfizer boosters, after Pfizer first/second dose; and 16 on heterologous schedule (i.e. Pfizer booster after AZ or Moderna or where primary dose was unspecified first and second doses).

d) Five of the 28 anaphylaxis Pfizer reports met the case definition criteria for anaphylaxis; of which 4 were heterologous, the fifth case was homologous, but the patient had received concurrent flu vaccine which is a potential co-suspect in the case. There were 9 reports of anaphylaxis events with Moderna booster doses, all reports on a heterologous schedule.

e) Within the 15-minute waiting time 17 events were reported and outside the 15-minute waiting time, 14 events were reported, but within the same day. The exact timings were not always specified, for instance – several said’<1 day’ or ‘after a few minutes’ or ‘outside the vaccination centre’. Six reports indicated an onset time of 5 minutes or less from vaccination.

f) There were no fatal reports, however 18 of the reports stated adrenaline was administered and 8 were hospitalised. It was noted that several had pre-existing allergies to a variety of allergens.

This story first appeared on our sister title, Pulse.