NIH launches study on allergic reactions caused by Pfizer’s coronavirus vaccine

The U.S. National Institues of Health (NIH) is planning to examine why a few people have suffered allergic reactions to Pfizer’s coronavirus vaccine.

Although the study is still in its early stages, the study is anticipated to enroll ‘several hundred’ people with a history of severe allergies and give them the jab under supervision, CNBC reported.

Dr Alkis Togias, of the NIH’s National Institute of Allergy and Infectious Diseases (NIAID), said his team hopes to start in a few weeks.    

Researchers hope to determine the component of the shot that has been causing life-threatening reactions known as anaphylaxis. has reached out to the NIAID for a request for comment.

The NIH’s National Institute of Allergy and Infectious Diseases will enroll ‘several hundred’ people with a history of severe allergies and give them Pfizer’s jab under supervision. Pictured: Rhoda Winkelman, 96, receives Pfizer’s coronavirus vaccine at New Jewish Home longterm health care facility in New York City, December 21

At least seven people in the U.S. have suffered serious side effects to Pfizer's vaccine (pictured), including anaphylactic shock

At least seven people in the U.S. have suffered serious side effects to Pfizer’s vaccine (pictured), including anaphylactic shock

Togias,chief of the NIAID’s Allergy, Asthma, and Airway Biology Branch. told CNBC that the study will have to be approved by the U.S. Food and Drug Administration (FDA) and an ethics committee before commencing. 

‘Of course, everybody when they hear a study that relates to the vaccine, we try to be sensitive and move fast,’ he said. 

‘But it is not something we can design today and start tomorrow.   

The Centers for Disease Control and Prevention (CDC) say at least seven healthcare workers have suffered adverse reactions to Pfizer’s jab.

Among them are three workers in Alaska and four people at a hospital in Libertyville, a Chicago suburb.


British regulators are advising that anyone who has a history of ‘significant’ allergic reactions to medicines, food or vaccines should not get the Pfizer coronavirus jab.

Allergic reactions to the vaccine are ‘very rare’, according to the trials involving more than 40,000 people.

Pfizer found a ‘very small number’ during its phase three clinical studies, or 137 out of 19,000 people who got the vaccine. But 111 people who were given a placebo also had allergic reactions. 

They also identified 12 possible side-effects from the vaccine, with seven identified as ‘very common’ meaning they are likely to affect more than one in ten people. Below are the known side effects.

The patient safety leaflet for the vaccine cautions that anyone with an allergy to any of the active substances in the vaccine should not receive the jab.

Allergic reactions to the vaccine are:

Very common (Likely to affect more than one in ten people)

  • Pain at injection site
  • Tiredness
  • Muscle pain
  • Chills
  • Joint pain
  • Fever
  • Headache 

Common (Likely to affect up to one in ten people)

  • Injection site swelling
  • Redness at injection site
  • Nausea 

Uncommon (May affect one in 100 people) 

  • Enlarged lymph nodes
  • Feeling unwell

At least three people went into anaphylactic shock, which is a severe and potentially life-threatening reaction to an allergy from food, medicine or even a type of material.

The immune system releases chemicals that flood the body, blood pressure suddenly drops, and airways narrow, which prevents someone from breathing normally.

Symptoms usually occur within minutes and include hives, a weak pulse, nausea, vomiting, dizziness and a swollen tongue or throat.

If not treated immediately, it can lead to death.

Sufferers often need a shot of epinephrine, a hormone that relaxes the airway muscles, to relieve symptoms. 

Reactions have only been reported in people who have received Pfizer’s shot, but the study may also look at Moderna’s because they have similar components.   

No volunteers in either clinical trial suffered severe allergic reactions, although researchers excluded people with a history of anaphylaxis. 

Participants did experience milder side effects, such as pain at the injection site, fatigue, fever and headache, but most resolved within a week. 

It’s currently unclear why people have suffered allergic reactions to the vaccine, which are very rare. 

Dr Peter Marks, director of the U.S. Food and Drug Administration’s Center for Biologics Evaluation and Research, said on Friday that researchers believe the allergic reactions could be due to  a substance called polyethylene glycol (PEG).  

PEG is a chemical compound found in laxative, creams and ointments that is also  present in both Pfizer and Moderna vaccines.

It is also found in laxatives as well as creams, ointments, and solvents

PEG has never been used in vaccine on the market, but it is has been in drugs that have triggered anaphylaxis.

Currently, the CDC recommends that clinicians observe people who get the shot for 15 minutes, or 30 if they have a history of severe allergic reactions.  

‘We are a little bit concerned that people who have had a lot of allergies who have had reactions like this to all kinds of things, not just vaccines, may be afraid to get vaccinated now,’ Togias told CNBC. 

‘We just don’t want that to happen. We want to find a way for them to get vaccinated.’ 

Allergic reactions haven’t just been reported in the U.S.     

In the U.K., two National Health Service  staff members with a history of severe allergies suffered reactions after being immunized.

One of the workers, a 49-year-old woman, had a history of egg allergies and the other, a 40-year-old woman, had a history of drug allergies.

Both of them carried devices that contain epinephrine, a hormone that relaxes the airway muscles, in case they suffered any reactions.

A third patient also had a ‘possible allergic reaction,’ but British authorities neither described it nor gave an update on the patient.

Pfizer says its jab is not made with any egg ingredients.

After the reactions, the U.K.’s Medicines & Healthcare products Regulatory Agency issued a warning that anyone with severe allergic reactions to food or medicine not be given the vaccine.