Experiencing COVID-19 symptoms? Hold off on getting your booster shot, experts say

While the number of Canadians who have received their third dose of the COVID-19 vaccine continues to increase, competing with it is the rise of the Omicron variant.

Health officials continue to urge Canadians to get their third dose as a way of protecting against severe infection. While symptoms of Omicron may be milder compared to other variants, concerns remain over its high rate of transmissibility.

So, what should someone do if they start to develop COVID-19 symptoms right before they’re scheduled to get their third dose?

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“People who have symptoms, with the prevalence of disease that we have, likely do have COVID and if you likely have COVID, now isn't the time to rush to the booster,” Dr. David Carr, an emergency physician at the University Health Network in Toronto, told CTVNews.ca in a phone interview on Wednesday. “We wouldn't recommend getting a booster shot in the course of an active infection.”

Instead, both Carr and Dr. Gerald Evans, chair of Queen's University's infectious diseases division in Kingston, Ont., recommend that anyone experiencing COVID-19 symptoms should hold off on getting their third dose until they have recovered. This applies whether or not the symptoms are actually related to COVID-19 or a different virus, both said.

Part of the reason for this is a “reduced immunogenicity effect” that often comes with getting any kind of vaccine while experiencing a viral infection, said Evans, particularly if the infection is severe.

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"We don't give it to you while you're acutely ill because the vaccine seems to have less of an effect in producing the response we want from the immune system," he told CTVNews.ca on Wednesday in a phone interview. "Your immune system doesn't seem to respond as well to the vaccine as it would when you're feeling well."

Generally speaking, this applies to any vaccine, both experts said. Another reason for this is that it can lead to confusion over whether any side-effects are related to the vaccine or a progression of the illness, said Carr.

“It confuses the clinical picture [and] can re-challenge your immune system, it’s just not the right time,” he said. “As a general rule of thumb, we don't want to introduce a vaccine when someone's not feeling well.”

HOW LONG SHOULD YOU WAIT?

Carr said that as a general principle with vaccines, it’s recommended to wait about a month after the onset of symptoms before getting vaccinated. If someone is infected with COVID-19, this provides them with more than enough time to recover, he said, and those who are infected with the virus should not be concerned about getting reinfected so soon after.

“A common parameter with most cases in virology is if you just had the illness, you're probably not going to get the exact same illness right away, you have high levels of circulating antibodies that are going to protect you,” he said. “If you had COVID with Omicron today, I can’t see you being reinfected in three weeks, that’s just not going to happen.”

But Evans said that thanks to post-vaccine surveillance following the billions of doses that have been administered worldwide, data suggests that there don’t seem to be any issues with getting a COVID-19 vaccine as soon as the more serious symptoms have recovered.

Symptoms of COVID-19 often include a new or worsening cough and fever, as well as a sore throat and nasal congestion, said Evans. Once these symptoms show signs of starting to resolve, it’s OK to go ahead with getting a third dose of the vaccine, he said.

“Once your throat’s not so sore anymore, your nasal congestion is clearing up, you can breathe well [and] you're not coughing anywhere near as much as you did…then that’s a reasonable time to book your vaccine,” he said.

But that doesn't necessarily mean people need to wait until they’re feeling entirely back to normal again before getting their third dose, Evans said.

“Even the healthiest people, after they get a cold or the flu, oftentimes have some sort of lingering symptoms that can go on for a number of weeks,” he said. “[Maybe] that cough has lingered on a little bit, or they're a bit more fatigued than they were before they were sick…don’t worry about those."

According to recommendations from the U.S. Centers for Disease Control and Prevention, if someone is experiencing any “moderate or severe illness,” it’s advised to wait until they recover before getting a COVID-19 vaccine. But for people with mild illnesses, or who have begun to see their symptoms improve, it’s possible to be vaccinated. Anyone who is, in fact, sick with COVID-19 is advised to postpone their vaccine until they have recovered from acute symptoms.

WHAT ARE THE NEXT STEPS?

If someone starts experiencing COVID-19 symptoms, the first step would be to determine whether or not they are COVID-19-related by using either a rapid antigen or PCR test, Carr said. This is especially the case for people who aren’t vaccinated, as they are at “substantially higher risk for severe disease,” he said.

Still, Carr said that challenges around access and eligibility requirements can make it difficult for some people to get tested. If it’s not possible to get tested right away, he recommends following local public health guidelines and self-isolating for the required amount of time until symptoms have improved for at least 24 hours. He also suggests calling a family physician for further guidance, if needed.

From there, Evans advises to continue watching how symptoms develop over time; only when they start to clear should someone get their third dose, he said.

“Be patient, put off your vaccine and rebook,” said Evans.