RSV Vaccine Side Effects

Getting a vaccine is a lot like starting a new workout plan: you feel proud, you feel prepared, and then your arm
acts like it just did 200 push-ups it absolutely did not do. If you’re here because you’ve heard the RSV vaccine
can cause side effects (and you’d like a heads-up before you roll up your sleeve), you’re in the right place.

This guide breaks down the most common RSV vaccine side effects, the rarer ones worth knowing about, and how to
tell the difference between “normal post-shot blah” and “call a medical professional.” It’s written in plain,
standard American Englishwith a little humorbecause reading about adverse reactions shouldn’t feel like
studying for a licensing exam.

First: What counts as an “RSV vaccine” in the U.S.?

In the United States, RSV vaccines are used mainly to protect older adults from RSV-related lower respiratory
tract disease (think: serious chest infections, not just sniffles). One RSV vaccine is also used during late
pregnancy to help protect newborns during their first months of life.

Common RSV vaccines you’ll hear about

• Arexvy (GSK) for adults (age and eligibility depend on guidance and licensing).
• Abrysvo (Pfizer) for adults, and also used during pregnancy (timed late in pregnancy).
• mResvia (Moderna) for adults (age and eligibility depend on guidance and licensing).

Who is typically recommended to get it?

Guidance changes over time, but current U.S. public health recommendations generally focus on:
adults age 75+ and adults ages 50–74 who have conditions or circumstances that increase the risk of severe RSV
(like certain chronic medical conditions or living in long-term care). RSV vaccination is generally a single dose
(not currently considered an “every year” vaccine).

If you’re pregnant, RSV vaccination is recommended only within a specific window late in pregnancy to maximize
infant protection and reduce concern for preterm birth risk if given earlier than recommended.

The short answer: Most RSV vaccine side effects are mild and temporary

For most people, RSV vaccine side effects look like the same “immune system doing its job” symptoms you might get
after other adult vaccines. These are usually mild, start within a day, and improve over 1–3 days.

Most common RSV vaccine side effects

• Arm soreness, redness, or swelling at the injection site
• Fatigue (the “why is my couch so magnetic?” feeling)
• Headache
• Muscle aches and/or joint pain
• Fever or chills (often low-grade)
• Nausea (reported more often in pregnancy with Abrysvo)
• Diarrhea (less common, but can happen)

These symptoms are typically a sign your immune system is responding. Annoying? Yes. Dangerous? Usually not.
Think of it as your body reading the “RSV wanted poster” and making a planjust with a little grumbling.

Side effects can vary by vaccine and by person

Even when vaccines target the same virus, they aren’t identical. And even when two people get the same vaccine,
they may not react the same way. One person feels fine and heads to brunch; another feels like brunch should come
to them… in bed… with a blanket.

Adults (older or higher-risk adults)

In clinical trials and real-world use, the most common reactions in adults are local injection-site symptoms and
short-term systemic symptoms like fatigue and headache. If you’ve felt crummy after a flu shot or shingles shot,
you might find the RSV experience familiarjust with its own personality.

Pregnancy (Abrysvo only, timed late in pregnancy)

In pregnant people receiving Abrysvo, common reported side effects include injection-site pain, headache, muscle
aches, and nausea. Timing matters: the vaccine is recommended during a specific late-pregnancy window to optimize
antibody transfer to the baby and to help reduce concern about preterm birth associated with vaccination earlier
than the recommended gestational window.

What’s considered “normal” vs. “not normal” after the RSV vaccine?

Normal (and usually short-lived)

• Arm soreness that peaks the first 24–48 hours
• Feeling tired, achy, or mildly feverish for a day or two
• A headache that improves with rest, hydration, and typical comfort measures
• Mild nausea that passes

Not normal (call a clinician for guidance)

• Symptoms that are intense, worsening, or lasting more than a few days
• Fever that’s high or persistent, especially with other concerning symptoms
• Severe pain, rapidly expanding redness, or warmth at the injection site (especially with fever)
• New or unusual neurologic symptoms (see the “rare but serious” section below)

Rare but serious side effects: what you should know (without spiraling)

Most people never experience serious problems after the RSV vaccine. Still, health agencies track safety signals
closely, and there are a few rare events that show up in official safety communications and prescribing
information.

Severe allergic reaction (anaphylaxis)

Severe allergic reactions to vaccines are rare, but they can happen. They typically occur soon after vaccination,
which is one reason vaccine sites often ask you to hang around briefly afterward.

Seek emergency care right away if you develop signs of a severe allergic reaction such as trouble
breathing, swelling of the face or throat, hives, dizziness, or weakness.

Fainting (syncope)

Fainting can occur after injectionssometimes due to anxiety, pain, or your body’s “nope” reflex. It’s not unique
to RSV vaccines. If you’ve fainted with shots before, tell the clinician so they can help you stay safe (like
having you sit or lie down).

Guillain-Barré syndrome (GBS): a rare neurologic condition

The U.S. FDA required updated warnings for some RSV vaccines after a postmarketing study suggested an increased
risk of GBS within the 42 days after vaccination. Importantly, the FDA has stated that evidence is not sufficient
to prove a causal relationship, but the safety signal was strong enough to add warnings and continue monitoring.

GBS is rare, and it can also occur after infections (including respiratory infections). Still, it’s wise to know
what to watch for.

When to get urgent medical advice for possible neurologic symptoms

• New weakness in the legs or arms
• Tingling or numbness that spreads or worsens
• Trouble walking, balance issues, or facial weakness
• Difficulty breathing (emergency)

If you notice these symptoms, don’t “wait it out.” Contact a healthcare professional promptly or seek emergency
care depending on severity.

Heart rhythm issues (reported in trials for some vaccines)

In some RSV vaccine clinical trials, atrial fibrillation (an irregular heart rhythm) was reported in a small
number of participants. A report like this doesn’t automatically mean the vaccine caused itbut it’s part of why
post-approval monitoring exists. If you have a history of heart rhythm problems, it’s reasonable to mention that
when you discuss RSV vaccination with a clinician.

Side effects when you get RSV vaccine with flu or COVID shots

You can often receive an RSV vaccine at the same visit as other adult vaccines (like influenza or COVID-19).
However, coadministration may increase the chance of short-term reactogenicitymeaning more soreness, headache,
muscle aches, or fever for a day or two.

Practical tip: if you’re the type who gets wiped out by vaccines, consider spacing them out when possible (unless
timing or access makes same-day vaccination the smarter choice).

How to feel better after the RSV vaccine (comfort measures that actually help)

Most post-vaccine symptoms are manageable with simple self-care. Always follow advice from your clinician,
especially if you’re pregnant, immunocompromised, or managing complex conditions.

For a sore arm

• Move your arm gently throughout the day (yes, even if it complains)
• Use a cool compress if swelling or soreness is annoying
• Avoid heavy lifting on that arm for 24 hours if it’s very tender

For fatigue, aches, or mild fever

• Hydrate and rest (your immune system is on shift)
• Light meals if you feel nauseated
• Ask a clinician what’s appropriate for you if you typically use over-the-counter pain relievers

If symptoms are getting worse instead of betteror your instincts say “this isn’t my usual vaccine reaction”reach
out to a healthcare professional.

Frequently asked questions about RSV vaccine side effects

Can the RSV vaccine give you RSV?

No. RSV vaccines don’t contain live RSV that can cause an RSV infection. The goal is to train your immune system
to recognize RSV, not to give you the illness.

How long do RSV vaccine side effects last?

Most people who have side effects feel them within the first day and improve within 1–3 days. Injection-site
soreness can sometimes linger a bit longer, especially if you tend to bruise or if the muscle was tense during
the shot.

Is it normal to feel “flu-ish” after?

Yes. Fatigue, achiness, mild fever, and headache can happen. It’s not RSV; it’s your immune system working.
The difference is usually time and intensity: vaccine symptoms are short-lived and should steadily improve.

Should you report side effects?

If something concerns youespecially symptoms that feel severe or unusualcontact a healthcare professional.
In the U.S., vaccine side effects can also be reported through established vaccine safety monitoring systems.

Experiences: What it’s like after the RSV vaccine (real-world, no dramajust honesty)

Let’s talk about the part people really want to know: “Okay, but how does it feel?” The most accurate answer is:
it depends. Your age, your immune system, your sleep, your stress level, and whether your body enjoys turning
minor inflammation into a full theatrical production can all influence how you feel afterward.

Experience #1: The ‘sore arm plus a nap’ classic. Many adults describe the RSV vaccine as a
straightforward combo: a tender upper arm and a wave of tiredness that shows up later the same day. They’ll say
things like, “I could’ve gone to the store, but also my couch and I entered a legally binding agreement.”
The next morning, they wake up feeling mostly normalmaybe still a little sorethen go on with life.

Experience #2: The ‘I feel like I’m getting sick… but I’m not’ moment. Some people report a
mild, flu-like feeling: headache, body aches, and a low-grade fever. This can be unsettling if you weren’t
expecting itespecially during RSV season when everyone’s a little jumpy about respiratory bugs. The key pattern
is timing and trajectory: the symptoms start soon after vaccination and improve over the next day or two.
If it’s escalating, lasting, or paired with respiratory symptoms like worsening cough or shortness of breath,
that’s when you check in with a clinician.

Experience #3: “I got it with my flu shot and regretted my scheduling choices.” People who get
multiple vaccines in one visit sometimes describe more intense short-term side effectsextra soreness, more
fatigue, or stronger achescompared with getting shots on separate days. It’s not necessarily harmful; it can
just be unpleasant. A common takeaway is: “Next time, I’ll schedule vaccines when I can take it easy the next
day.” If you’re caring for someone else or have a demanding work schedule, planning for a lighter day afterward
can make the experience feel much more manageable.

Experience #4: Pregnancy perspectivemild but annoying symptoms. For pregnant people receiving
Abrysvo in the recommended late-pregnancy window, the most common experience descriptions are pretty consistent:
sore arm, headache, muscle aches, and sometimes nausea. Many describe it as “similar to other pregnancy-era
vaccines,” with symptoms that resolve quickly. Because pregnancy already comes with its own buffet of aches and
fatigue, some people say it’s hard to tell what was the vaccine versus “being pregnant,” which is its own sport.
The most practical advice reported by many is to schedule the shot on a day when you can rest, hydrate, and keep
meals simple.

Experience #5: The reassurance factor. A lot of people report that any temporary discomfort
feels “worth it” because RSV can be genuinely dangerous for older adults and certain high-risk groups. It’s
common to hear: “I didn’t want to mess around with a virus that can land you in the hospital.” That doesn’t mean
side effects should be dismissedonly that it’s reasonable to weigh short-term discomfort against potential
protection from severe disease, especially if you’re in a higher-risk category.

Bottom line: most experiences are mild and short. Plan for the possibility of a low-energy day, and don’t ignore
severe, unusual, or worsening symptoms. Your body’s job is to protect you; your job is to give it a little grace
and a little hydration while it does the work.

Conclusion

RSV vaccine side effects are usually mildthink sore arm, fatigue, headache, aches, and sometimes low fever or
nausea. These symptoms typically fade within a couple of days. Rare serious risks (like severe allergic reactions
or neurologic symptoms consistent with GBS) are important to recognize, but they remain uncommon, and safety
monitoring continues. If you’re eligibleespecially if you’re older, higher-risk, or pregnant in the recommended
windowtalk with a healthcare professional to weigh benefits and risks in a way that fits your health history.