Measles: What Parents Need to Know

And why is it so important to vaccinate against it

We unfortunately live in a world where misinformation and disinformation is so rife on social media when it comes to measles and the MMR vaccine. You are led to believe that measles is just a mild illness, a rash that passes and that your child’s natural immunity will easily take care of it. Couple that with the scaremongering perpetuated about vaccines in general and the MMR in particular, and you have a perfect storm culminating in measles outbreaks, significant morbidity and even avoidable and preventable deaths. In Ireland now, we are not achieving herd immunity rates of MMR vaccinations and it is inevitable that we will begin to see outbreaks in the near future.

Measles is far more than just a red rash—it’s a serious, super-contagious viral illness. Around 90% of those who aren’t immune will catch it if they’re exposed to someone who’s infected. For parents, this statistic can feel scary, but knowledge truly is power. Below, I’ve laid out the essentials of measles, from what happens in the body, to how the infection spreads, to the details about the MMR vaccine. I’ll also dive into the infamous Andrew Wakefield controversy and the debunked rumour that MMR causes autism (spoiler alert: it doesn’t).

“You’re just a puppet of Big Pharma!”

Yes, that’s exactly right. Every night, I roll around in my secret stash of pharma gold coins, delivered straight from a hidden underground vaccine lair. My contract? To spread wild propaganda like "Measles is bad" and "Preventable diseases should be prevented." The truth is, I promote vaccines not because I get kickbacks (which, for the record, I don’t), but because I’ve actually seen what happens to babies and children who catch measles. It’s not a mild rash; it’s hospital beds, ventilators, and, in some cases, funerals. So, if protecting children from suffering means standing by science and evidence, then count me in.

Grab a cup of tea, and let’s demystify measles together.

1. The Basics of Measles

How It Spreads

Measles is caused by the measles virus, which travels through respiratory droplets. When someone coughs, sneezes—or even just breathes—in a shared space, the virus can linger in the air for up to two hours. This means that you don’t have to stand face-to-face with an infected person to catch measles; simply being in a room where they recently were can be enough (can you imagine how quickly it can spread on an plane!)

Measles is one of the most contagious viruses known to humans. A single person with measles can infect 12 to 18 others in an unvaccinated population, giving it an R₀ (basic reproduction number) of 12-18. In comparison, the seasonal flu has an R₀ of around 1.3 to 1.8, meaning each person with the flu typically infects only one or two others. This stark difference explains why measles spreads like wildfire in communities with low vaccination rates—just one case can trigger an outbreak.

Key Symptoms

• Stage 1: Incubation
  After the virus sneaks in (typically through the nose, mouth, or even your eyes), you won’t notice anything for about 6 to 21 days. This is the quiet period when the virus is busy replicating, but outwardly, things can seem normal.

• Stage 2: Prodrome
  Next comes the classic “3 C’s”: cough, coryza (runny nose), and conjunctivitis (red eyes). Fever can shoot up (as high as 40°C/104°F), and your child may look generally miserable. This phase can last two to four days—sometimes up to a week—and ramps up right before the rash breaks out.

Koplik spots, which look like tiny white or bluish spots on a red base (often described as “grains of salt on a red background”), can appear inside the mouth about 1–2 days before the rash. These little spots are quite specific to measles and can help doctors make the diagnosis early.

• Stage 3: The Rash (Exanthem) Usually about two to four days after that fever kicks in, a maculopapular rash (red and bumpy) starts on the face and hairline, then spreads downward over the body. Early on, if you press the spots, they blanch (turn white), but in later stages, they don’t. Some children’s rashes can include small petechiae (tiny red dots from bleeding under the skin); occasionally, the rash can look haemorrhagic.

During this rash phase, fever may peak, and symptoms like sore throat, cough, and red eyes can worsen. Typically, the rash lasts about a week, then starts to fade in the order it appeared.

• Stage 4: Recovery After a few days of the rash, the fever usually goes down. Cough, however, can hang around for a couple of weeks. If fever sticks around beyond the fourth day of the rash, doctors become more concerned about complications like pneumonia or ear infections.

Infectious Period

People with measles can pass the virus from five days before the rash appears to four days after it shows up (that’s quite a window). That’s why measles spreads so easily in communities where people aren’t vaccinated.

2. Variations of Measles and Special Cases

• Modified Measles: If someone (often an infant under nine months old who still has partial maternal antibodies) has just enough measles immunity to make the illness milder, they might get a longer incubation and milder symptoms than the classic form.

• Atypical Measles: This is mostly historical, seen in people vaccinated in the 1960s with an old “killed” vaccine no longer in use. The rash and symptoms can behave oddly and be more severe, but fortunately, it’s now rare.

• Immunocompromised Patients: Folks with T-cell problems or who are on immunosuppressive therapies can get extremely serious measles infections. Sometimes, they don’t even get a rash. They’re at high risk for giant cell pneumonia or measles inclusion body encephalitis (MIBE)—both are mouthfuls to say but are even scarier to experience.

3. Complications (Yes, They’re Frightening)

Certain groups are at higher risk for severe complications from measles. Infants under one year are particularly vulnerable since their immune systems are still developing, and the protective antibodies they receive from their mothers start to fade around 6–9 months. Immunocompromised individuals, including those with cancer, HIV, or organ transplants, are also at risk, as their bodies struggle to fight off infections. Pregnant women face serious dangers too—measles can lead to miscarriage, premature birth, and low birth weight in newborns. Measles is not a “simple childhood disease.” Roughly 1 in 3 people with measles can get at least one complication. Here are the main culprits:

1. Diarrhoea: The most common complication. It sounds relatively harmless, but can lead to dehydration and the need for hospital admission, especially in young kids.

2. Ear Infections (Otitis Media): These happen in up to 10% of measles cases and can sometimes result in hearing damage if severe.

3. Pneumonia: The most common cause of measles-related death in kids. Around 6% of measles patients develop pneumonia, and it can be viral pneumonia caused by the measles virus itself or a secondary bacterial infection.

4. Neurologic Issues:

   • Encephalitis (1 in 1000 cases): Brain swelling that can happen a few days after the rash. Can lead to seizures or long-term neurologic damage in about 25% of children who get it.

   • Acute Disseminated Encephalomyelitis (ADEM): A post-infectious, autoimmune attack on the brain’s myelin (the protective sheath around nerves). Can be fatal in up to 20% of measles-related cases.

   • Subacute Sclerosing Panencephalitis (SSPE): This is a very scary ticking time bomb-sort of scenario. SSPE is a fatal, progressive condition of the central nervous system. It usually appears years after measles infection (average 7–10 years later). The risk is highest in kids who had measles young (especially under 1 year of age). It starts subtly with behaviour changes or decline in school performance, and progresses to myoclonic jerks, neurologic deterioration, and eventually death. Despite its rarity, SSPE is a big reason doctors work so hard to contain measles outbreaks. During the 1989–1991 measles resurgence in the U.S., the risk of SSPE was estimated at 200 per million—over 10 times higher than previous estimates, though underreporting likely skewed this number. Later, a study of California measles cases (1998–2015) found that children infected before age five had an SSPE risk of 1 in 1,367, and for those infected under 12 months, the risk jumped to 1 in 609.

4. Infants in the First Year: Maternal Antibodies

Newborns often receive a type of passive immunity through antibodies passed via the placenta from moms who are immune. But these protective antibodies usually fade within a few months. Babies born to mothers who had natural measles infection (back in the day) might carry those antibodies a bit longer than babies whose moms were only vaccinated. Nevertheless, this protection isn’t foolproof or especially long-lasting, which is why vaccinating on time is so important.

5. The MMR Vaccine

What’s In It and How It Works

The MMR vaccine protects against Measles, Mumps, and Rubella—three viruses that can wreak havoc in unvaccinated communities. It’s a “live attenuated” vaccine, meaning the viruses are weakened but still spark a robust immune response. Some parents worry about giving more than one virus at once, but research has shown that MMR is extremely safe and effective.

In many places, MMR is given at around 12–15 months of age, with a second dose at 4–6 years. This two-dose schedule is crucial. The first dose catches most kids (with around a 95% protection rate for measles), while the second dose boosts immunity to nearly 99%.

Infants Traveling or at High Risk

Sometimes children are given an “early” dose (as early as 6 months old) if they’re traveling internationally or there’s a local measles outbreak. This dose doesn’t count as part of the standard two-dose series, so kids will still need two more doses when they’re old enough. It’s all about ensuring they’re protected ASAP in high-risk situations.

Safety and Potential Side Effects

• Fever: About 1 in 6 children may get a fever in the first week or two after the shot.

• Rash: A small percentage develop a mild rash, often fewer than 1 in 20.

• Febrile Seizures: The MMR can cause a slight uptick in febrile seizures about a week or two after vaccination, but these seizures are typically brief and not harmful in the long run.

No Link to Autism

Let’s address the elephant in the room: the Andrew Wakefield controversy. Back in 1998, Andrew Wakefield published a small study suggesting a link between the MMR vaccine and autism. It turned out that his work was flawed, riddled with conflicts of interest, and ultimately fully retracted by the medical journal. His medical license was revoked. Subsequent large studies (we’re talking hundreds of thousands to millions of kids) have shown no link between MMR and autism. Despite the mountain of evidence debunking this myth, the rumour persists online—and misinformation can spread even faster than measles. It’s important to rely on data that’s been repeatedly confirmed by experts around the globe.

Why We Still See Measles Outbreaks

Simply put, measles is wildly contagious. When vaccination rates dip in a community—even slightly—there’s enough unvaccinated “fuel” for the virus to spark an outbreak. Herd immunity usually requires about 95% vaccination coverage. If those rates drop, cases can pop up quickly and spread like wildfire.

6. Treatment and Vitamin A

Once a child has measles, there’s no specific medication that magically makes it go away. It’s mostly supportive care: fluids, fever control, and watching for complications. Vitamin A is recommended by the World Health Organization (and many national health agencies) for kids with measles, especially those who may be vitamin A deficient. It helps reduce the risk of severe outcomes like blindness and can shorten the course of the illness.

7. Why Vaccination Is So Important

• Personal Protection: It keeps your child from dealing with 1–2 weeks of serious misery (and the possibility of life-threatening complications).

• Community Immunity: Babies too young to receive the vaccine, pregnant women, and people with cancer or immune conditions rely on a vaccinated community to stay safe.

• SSPE Prevention: While rare, SSPE is devastating. It’s 100% preventable by preventing measles in the first place.

• Global Impact: Measles is still a major killer worldwide. High vaccination rates help reduce global disease and death.

8. Final Thoughts

Measles may sound like an old-timey disease, but it’s still around lurking and ready to spread given the slightest opportunity. The good news? This is one of the most preventable illnesses on the planet, thanks to the MMR vaccine. Despite some persistent myths floating around, massive research confirms both the safety and the powerful protection these vaccines provide.

By immunizing our children, we’re not just keeping them safe from a fever and rash. We’re preventing ear infections, pneumonia, and, in extreme but real cases, irreversible brain damage or death. We’re creating a healthier future for them—and for their classmates, neighbours, and friends.

Remember: If you have any questions or concerns, reach out to a trusted paediatrician or qualified healthcare provider. In a world of viral (pun intended) misinformation, turn to genuine experts who have spent their careers studying these diseases. The best gift we can give our kids is a strong, healthy start—and that includes protection from measles.

Stay informed, stay thoughtful, and stay vaccinated.

Thanks for reading—I know this can be a lot to digest, but hopefully it helps you feel more confident about measles and the MMR vaccine. If you found this helpful, consider sharing to spread the word (pun totally intended).