Practical guide · 5 min

Vaccination: what can happen, and how rarely

Most people feel nothing more than a sore arm. We still want you to know what can happen, how likely it is, and what we do about it. If you’re choosing vaccination at home, the second half of this page is for you.

What’s normal

A sore arm means it’s working

These aren’t allergic reactions. They’re your immune system responding, and they settle on their own.

Sore arm. By far the most common. The muscle aches for a day or two. Moving the arm helps, and paracetamol is fine if you need it.
Redness or mild swelling where the needle went in. Usually gone in two or three days.
Mild fever, tiredness, headache or muscle aches. Usually the first day or two.

Some vaccines have their own pattern, such as a mild fever and rash a week or so after MMR. The nurse or doctor will tell you what to expect from yours.

None of this is dangerous, but please tell us anyway. We like to hear.

Allergic reactions

The real risk, and how to recognise it

Allergic reactions are rare, and they come in two kinds.

A mild allergic reaction is itching, a rash or hives (raised, itchy welts), in one spot or across the body, with normal breathing. It’s uncomfortable, not dangerous, and an antihistamine treats it.

Anaphylaxis is a severe allergic reaction. Swelling and a drop in blood pressure can affect your breathing. The signs:

difficulty breathing
tightness in the throat or a hoarse voice
swelling of the face, lips or tongue
widespread hives together with any of these
severe dizziness or fainting
repeated vomiting

Anaphylaxis almost always starts within 15 to 30 minutes of the injection, which is why we keep you with us for 30 minutes afterwards. It’s treated with an injection of adrenaline (epinephrine), which reverses the reaction directly, followed by a check in an emergency room. Antihistamines do not treat anaphylaxis.

The numbers

How rare is rare

Each bar shows where a reaction sits between “almost everyone” and “one in a million.” Every step along the line is ten times rarer than the one before.

1 in 2

Sore arm50–80% of people, depending on the vaccine
1 in 5

Mild fever, tiredness or headache10–30% of people
1 in 10,000to 1 in 100,000

Mild allergic reactionRash or hives, 0.001–0.01% of doses
1 in 760,000

AnaphylaxisAbout 1.3 per million doses

A sore arm is likely. A rash is rare. Anaphylaxis is about 1 in 760,000 doses: fill a 75,000-seat stadium ten times over, and you’d expect it in roughly one person across all ten crowds. It’s treatable, and we’re ready for it.

In a US study of more than 25 million doses, none of the people who had anaphylaxis died.

Source: US Vaccine Safety Datalink (McNeil et al., 2016) and vaccine trial data.

Before your appointment

Five things to tell us first

any allergies, especially to eggs, gelatine, latex or antibiotics
any previous reaction to a vaccine, however mild
asthma
pregnancy, or the chance you might be pregnant
any condition or medication that affects your immune system

After you leave

Go first, call us later

Go to the nearest emergency room straight away if you have any of the anaphylaxis signs above. Do not call us first.

Getting to the emergency room is the priority. Once you’ve been handed over to the ER team and have a moment, let us know. It’s important, but it isn’t urgent, and it can wait until you’re safe.

Reactions can occasionally start hours after the injection, including a second wave after a first reaction has settled.

If it’s only a rash or hives and your breathing is normal, message us on WhatsApp. An antihistamine usually settles it.

Vaccination at home

What changes when the nurse comes to you

Home vaccination is convenient, and we do it regularly. It’s also different from being vaccinated at the clinic, and we want you to choose with the full picture.

At our Bali clinic there’s a doctor in the building, with the full equipment and team. At home, one of our nurses gives the vaccination, with no doctor physically present. A Padma Care doctor stays reachable by phone or video for the whole visit.

The one thing that’s different

Everything above applies wherever you’re vaccinated. The difference at home is what happens in the rare event of anaphylaxis.

Our nurse carries two doses of adrenaline: one to give immediately, and a second if it’s needed. Adrenaline is the most important treatment. What the nurse can’t bring to your home is what a clinic or hospital has if adrenaline alone isn’t enough: oxygen, airway equipment, intravenous fluids, and a doctor in the room. Reaching that level of care takes longer from your home than from the clinic.

Anaphylaxis is rare. Anaphylaxis that adrenaline alone doesn’t control is rarer still. That’s the risk you’re accepting. We prepare carefully to reduce it, but a reduced risk is still a risk, and we don’t want you to decide without knowing it.

How we prepare

Before the visit, we identify the closest emergency room we can reach and tell you which one it is.
The nurse brings an emergency kit: two doses of adrenaline, plus antihistamine.
Our driver stays on standby for the whole visit, so we can leave for the emergency room at once.
The nurse stays with you for at least 30 minutes after the injection, when nearly all serious reactions appear.
A Padma Care doctor is reachable by phone or video throughout.
We check your health history beforehand: the five things above.

If anaphylaxis happens at home

The nurse gives adrenaline straight away, and a second dose if it’s needed.
The nurse calls the emergency room we identified, so they’re ready for you.
Our driver takes you there, with the nurse beside you.

You don’t need to decide or arrange anything. That’s the nurse’s job.

When we’ll book the clinic instead

For your safety, we vaccinate at the clinic rather than at home if you have:

had an allergic reaction to a vaccine before, of any severity
asthma (if a few more questions show it’s well controlled, we may make an exception)
a known severe allergy to anything in the vaccine

If any of these apply and a home visit is already booked, tell us and we’ll switch it.