Allergies to vaccine ingredients shouldn't stop patients from getting COVID-19 shots: experts
Despite caution from NACI, allergists say virtually everyone can get a shot safely
Years ago, people who were allergic to eggs were given blanket advice to avoid getting the flu shot, which is manufactured using an egg-based process.
Today, the influenza vaccine is widely regarded as safe even for patients with egg allergies. But specialists still routinely get referrals from doctors who aren't sure if their clients should get the shot, said Dr. Mariam Hanna, a pediatric allergist and immunologist in Burlington, Ont.
Hanna uses this as an analogy for the referrals she is now getting from doctors with patients who have concerns about allergies to ingredients in the three COVID-19 vaccines being administered in Canada.
Patients can have an allergic reaction to polyethylene glycol (PEG), for example, a component of both the Pfizer-BioNTech and Moderna mRNA shots, "and in many cases can still tolerate the vaccine," she said.
Canada's National Advisory Committee on Immunization says patients with a suspected but not proven allergy to PEG can get a COVID-19 vaccine, but says the vaccines "should not be routinely offered to individuals who are allergic to any component of the specific COVID-19 vaccine or its container."
Yet Hanna said patients with a confirmed allergy to PEG are still able to get the vaccine while under supervision from an allergist, who may choose to administer it through multiple smaller doses or instead offer a non-mRNA vaccine.
"We shouldn't really have a blanket … exemption and [have] nothing that we can offer you. No, at this day and age, the allergists are able to intervene, offer some options," she said.
In Manitoba, about 15-25 per cent of referrals to the allergy clinic at the Health Sciences Centre are for patients who haven't had their first dose of a COVID-19 vaccine, said Dr. Lana Rosenfield, an allergist and clinical immunologist.
"We have been receiving a large amount of consultation for people who are concerned about, have had a reaction to the first dose of the vaccine or even now getting people who've had reactions to a second dose," she said.
But Rosenfield, like Hanna, said virtually every patient she sees is given the green light to get the shot.
"There are some very rare types of non-typical allergies that might be a reason to not get the vaccine. We maybe have seen one as a group, but overall — in terms of anaphylaxis, severe kind of immediate reaction to vaccine, kind of delayed rashes, delayed hives, all of those patients — we have the ability to give them the vaccine," she said.
714 reported adverse effects
The Manitoba government said as of Aug. 22, there have been 714 reports of adverse effects from COVID-19 vaccines.
There appears to be an increased risk of myocarditis (inflammation of the heart muscles) occurring within seven days of a patient getting a second dose of an mRNA vaccine — among 12- to 29-year-old males and 20- to 29-year-old females — a spokesperson for Manitoba's vaccine task force said. As of Aug. 15, the province had received 14 reports of the illness.
The task force also said it has received three reports of patients getting a blood clot after receiving the AstraZeneca-Oxford vaccine.
Some must wait months
Concerns about getting an allergic reaction to a vaccine component are not the only medical reason that a patient may have for not getting the shot, whether approved by a specialist or not.
In Manitoba's clinical guidance to immunizers and health-care providers, there is a list of groups of patients who are unlikely to mount an acceptable immune response from the COVID-19 vaccine.
It includes some getting recent cancer treatment or stem cell transplants and people on eight different medications.
"There are patients that are on chronic immunosuppressants where their response to the vaccine may not be as good as we want," said Hanna.
Doctors must then decide whether to decrease the medication to improve the vaccine's response, or accept "suboptimal response [that's] better than nothing," she said.
Dr. Tim Hilderman, a medical officer of health for Manitoba, said there are virtually no absolute contraindications that would prevent someone from getting a COVID-19 vaccine but there may be occasions where doctors will recommend a patient waits before getting immunized.
"The short answer is that it is a very small [number] which we would not be recommending vaccination. It's a handful. It's a really small number of people," he said.
Rosenfield is encouraging anyone who thinks they can't get the shot to get a referral to the allergy clinic at Health Sciences Centre.
"It's always an exciting time in the clinic when we're able to get everybody their 'I've been vaccinated' sticker at the end and everybody's been thankful that we've been able to give them the vaccine."
WATCH | Being allergic to vaccine components doesn't necessarily preclude patients from getting shot: