London: The UK medicines regulator advised on Tuesday that anyone who has a history of 'significant' allergic reactions to medicines, food or vaccines should not get the Pfizer coronavirus vaccine.
Dr June Raine, the chief executive of the Medicines and Healthcare products Regulatory Agency (MHRA) said that this was not identified in the trials.
"We know from very extensive clinical trials that this wasn't a feature," she said.
Studies had identified 12 possible side-effects from the vaccine, with seven identified as 'very common' meaning they are likely to affect more than one in 10 people.
It is mentioned in the patient safety leaflet that anyone with an allergy to any of the active substances in the vaccine should not receive the jab. It adds, "signs of an allergic reaction may include itchy skin rash, shortness of breath and swelling of the face or tongue."
The UK's world-first COVID-19 vaccine rollout has hit the problem within 24 hours after anyone with a serious allergy to medicines or food was told not to have the Pfizer jab because two National Health Service (NHS) staff fell ill after the vaccination.
The number of people to be barred is not known yet, however, seven million people in Britain have allergies severe enough to require medical care, according to the NHS, while around 250,000 people need to carry an EpiPen at all times.
Both the unnamed healthcare workers, who carried EpiPens are 'recovering well' from reactions suffered shortly after their injections on the first day of Britain's biggest ever mass vaccination programme yesterday.
Despite the two allergy cases, the government is continuing to vaccinate between 5,000 and 7,000 people per day across the UK with 800,000 Pfizer doses already in hospitals and millions more on the way.
The two NHS staff suffered an anaphylactoid reaction to the vaccine, which is milder than anaphylaxis, and tends to involve a rash, shortness of breath, swelling of the face and tongue or a drop in blood pressure, the NHS said.