Some readers wrote to NPR with concerns about a whole slate of unusual conditions they've been noticing in the aftermath of their own vaccines.

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Some readers wrote to NPR with concerns about a whole slate of unusual conditions they've been noticing in the aftermath of their own vaccines. / Getty Images

Each week, we answer "frequently asked questions" about life during the coronavirus crisis. If you have a question you'd like us to consider for a future post, email us at goatsandsoda@npr.org with the subject line: "Weekly Coronavirus Questions."

We've reported on some of the typical side effects many of us will experience after getting vaccinated against COVID-19. Since then, some readers wrote to NPR with concerns about a whole slate of more unusual conditions they've been noticing in the aftermath of their own vaccines.

Some of those write-ins complained about hearing loss, others mentioned ear ringing, there were a few notes of vertigo, abnormal menstrual cycles and, oh, let's not forget the purple toe issue! ( Yes, we checked: "COVID toe" is indeed a thing.)

The time is particularly ripe for all such vaccine-side-effects-discourses: With the Johnson & Johnson COVID-19 having been put on pause due to concerns over (rare) reports of blood clots, you might be wondering what to make of these serious and not-so-serious off-kilter cases.

Dr. Lisa Adams, the dean of public health at the Dartmouth Geisel Medical School, says in order to answer that question, we need to take a step back and be careful about our assumptions.

To start, she says, we simply don't know whether these weirder symptoms are really linked to the vaccine at all.

Unlike the much more common COVID vaccine side effects — like fever, chills, and headache — there isn't really great data about these unusual cases, Adams explains. Information about things like vertigo and ear-ringing are still being collected on a mass scale and we still can't say with certainty that these more unusual effects are causally tied to the vaccine.

That's especially since mindset may play a role, Adams explains. After getting the jab, individuals might simply be more attuned to the minutiae of how they're feeling physically — and, therefore, be prone to noticing more "symptoms," including small things that might've happened anyway.

Conversely, it may also be the case that some of these side effects do end up correlating with the vaccine — particularly as our understanding of these issues evolve and we get more data, Adams explains.

Right now, we just don't know for sure, one way or the other.

There's one more reassuring factor to keep in mind here: The frequency of these more unusual effects is pretty low, says Dr. Gomez-Duarte, the division chief of infectious diseases at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo. Only a small number of individuals have reported experiencing problems with hearing and vertigo, Gomez-Duarte says, and most COVID-19 vaccinations proceed safely, with mild effects.

So how to explain the "rare" cases, as Gomez-Duarte puts it — and what to do if you yourself end up in one of these ear-ringing, head-pounding situations?

Gomez-Duarte says that normally, when a person receives a vaccine, an immune response is stimulated that directs antibodies against antigens that were injected into the body, building up your resistance to a virus. But in some people, Gomez-Duarte hypothesizes, some of that response gets directed to proteins that the individual has in the skin, or in blood vessels, or in the ears, lungs and heart.

"So there might be a sort of cross-reaction, where those immune responses recognize proteins within the individual," he explains. "If it's in the skin, you might see a skin rash; if it's in the nervous system, there might be issues with pain, or inability to move; if it's the lung, then this individual might wheeze."

Adams says contact your health-care provider if you have any questions. But there are also some red flags you should look out for that would absolutely warrant immediate medical attention: severe headache, abdominal pain, severe wheezing or swelling in legs (indicating a clot).

Gomez-Duarte also calls attention to certain skin-level symptoms — like severe bruising, or small dots that are red in color — which both might be precursors of a more severe response.

Both Gomez-Duarte and Adams agree that a lot of talk about side effects may heighten vaccine hesitancy — particularly as infrequent cases get inflated coverage.

On that front, both experts urge reassurance: For the vast majority of people, the side effects of vaccination are mild and they're worth the price of bringing a quicker end to this crisis.

Gomez-Duarte puts the bottom line simply: "What's most important is that people who are eligible for immunization get immunized."

And on a similar note, Adams encourages individuals to register their vaccine in apps like V-Safe tool if you have a smartphone. Recording your symptoms into digital databases can help public health agencies collect information about the vaccine's effects, Adams says, bringing us closer to a fuller understanding of how all of this works.

"That's truly what we need," she emphasizes. "We need to be doing surveillance [of post-vaccine symptoms]."

Pranav Baskar is a freelance journalist who regularly answers coronavirus FAQs for NPR.

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