Can I get the COVID-19 vaccine if I have allergies?

Welcome to Vaxx Populi, Maclean's ongoing series tackling the most pressing questions related to the COVID-19 vaccines.

On Dec. 14, Canada initiated the most complex vaccination project the country has seen to date: inoculating the population against COVID-19. As health care workers, long-term care residents and others in high-risk categories receive the first shots, Maclean’s rolls out Vaxx Populi, an ongoing series in which Patricia Treble tackles the most pressing questions related to the new COVID-19 vaccines.

Today’s question:

Can I get the COVID-19 vaccine if I have allergies?

The most common complaints reported by people who have received the Pfizer COVID-19 vaccine are discomfort at the injection site, fatigue and headaches, with some of those in the medical trial reporting that they felt “a bit more fatigue with the second shot,” said Dr. Supriya Sharma, Health Canada’s chief medical adviser, when she announced that the two-shot vaccine had been approved for use in Canada. Those reactions are “in line with other vaccines,” said Sharma. 

Still, as more and more countries start their vaccination programs, Canadian and other regulators are sharing information about any adverse reactions reported by those receiving the vaccine, said Dr. Marc Berthiaume, director of Health Canada’s bureau of medical sciences. As well, the monitoring of the health of the 40,000 phase-three trial participants continues. On Dec. 8, two health workers in Britain had serious allergic reactions after being given their first dose of the Pfizer COVID-19 vaccine. The workers, who recovered well, had a “history of significant allergic reactions,” according to Stephen Powis, national medical director for the National Health Service, and reportedly carried adrenaline autoinjectors (Epi-Pens or a variant). (There was one anaphylactic reaction reported by a participant who got the vaccine in Pfizer’s phase-three trial, according to data published by the U.S. Food and Drug Administration, though anyone with a history of severe reactions to vaccines or the ingredients to this particular vaccine was excluded from that trial.)

RELATED: COVID-19 vaccine tracker: A guide for Canadians

On Dec. 12, Health Canada issued official guidance for those with serious allergies. Noting that all vaccines in Canada “carry a warning about the risk of serious allergic reactions, including anaphylaxis, and immunization clinics are equipped to manage these rare events,” the federal government warned that “people with allergies to any of the ingredients of the [Pfizer COVID-19] vaccine are currently cautioned against receiving it.” 

In addition to the mRNA of the vaccine (the genetic material itself is unlikely to cause an allergic reaction, Dr. William Schaffner, a vaccine expert at Vanderbilt University, told the New York Times)—the ingredients include:

  • cholesterol
  • sucrose
  • potassium chloride
  • sodium chloride
  • water for injection
  • dibasic sodium phosphate dihydrate
  • monobasic potassium phosphate
  • ALC-0315 = ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
  • ALC-0159 = 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide
  • 1,2-Distearoyl-sn-glycero-3-phosphocholine

As well, Health Canada advised that if you have “experienced a serious allergic reaction to another vaccine, drug or food, you should talk to your health professional before you receive the vaccine.”

BOTTOM LINE: Many Canadians, age 16 and over, could experience mild or moderate reactions to the Pfizer vaccine, in line with what occurs with other vaccines, meaning they could last a few hours or a few days after immunization. Still, just as when people get other vaccines, including the seasonal flu shot, they will have to remain at the vaccination site for a while to make sure they are not having a more serious reaction.