Global Progress Toward Ending Measles & Rubella: Expert Insights from Dr. Natasha Crowcroft

Key Takeaways

• Measles outbreaks are rising across all World Health Organization (WHO) regions due to coverage gaps and waning immunity 

• Eliminating measles demands extremely high vaccination rates, strong health-systems, and outreach to every child 

• Rubella elimination appears within reach thanks to integrated MMR strategies and lower transmission thresholds 

• Vaccine hesitancy and system-level access barriers differ by context and must be addressed through tailored strategies 

• Global coordination, political commitment, and partnership (WHO, Gavi, national programs) remain critical 

The Resurgence of Measles and Rubella

Measles is making a comeback. Last year, every WHO region reported increased numbers of measles cases. Patients in more than half of the reported cases were hospitalized. As of November 2025, the Americas, including Canada and the United States, lost their status as a measles-free region due to outbreaks that persisted for more than a year. 

Why Measles Remains so Difficult to Eliminate

Because measles is so infectious — 9 out of 10 people will catch the disease if they are exposed but not vaccinated — it takes a very high vaccination rate in the entire population to prevent measles from spreading, explains Dr. Natasha Crowcroft, who spent more than five years as the Senior Technical Advisor on Measles and Rubella for WHO. 

Here Crowcroft tells us: 

• Why it’s so challenging to stop measles globally 

• What drives vaccine hesitancy 

• Why rubella, unlike measles but in the same vaccine, may soon be eliminated 

The measles vaccine has been one of the most successful vaccines ever, estimated to have saved more than 60 million lives just since 2000. Why the increased outbreaks and why are measles vaccines not reaching everyone who needs them?

That’s the problem — you can’t stop these outbreaks unless you reach everybody with vaccines. The reason it’s a challenge everywhere is because measles is the most infectious virus we know of. It spreads like wildfire. 

If there’s a single child who’s susceptible, they’ll catch measles just walking into the room with someone who is infected. So first of all, we’re starting with the immense biological challenge of trying to control this very infectious virus. Then, even with the best vaccine in the world, it only works if it reaches almost every child. And you can face real challenges reaching every child. 

Such as?

The reasons vary from country to country. We talk a lot about vaccine hesitancy in high-income countries. But when you move to middle-income and low-income countries, it’s usually much more a question of how the health system is organized and how well-organized clinics are, where they are, and if children can get to them. It’s almost like a military operation running a really good immunization program. Every piece of the chain has to work perfectly to make sure that the country has the right vaccines in their program, can get them to everywhere they need to be through a cold chain that works, has the clinics, has the highly trained health providers there to reach the kids. 

 Is it impossible to immunize every child?

It’s a huge challenge to reach every child, especially if it’s a country where they haven’t had a census for 15 or 20 years, where they have really remote areas that take days to reach, where there are no roads or the roads turn into rivers in the rainy season. But there are countries that do it despite roads that turn into rivers, despite urban settings where there’s huge inequality. They manage to reach children. We do know how to do it, but that doesn’t make it easy.  

What efforts have been most effective at increasing vaccine access?

We don’t work alone. The World Health Organization is a membership organization. We work with the countries primarily, countries where everything starts. That’s where it happens. And we work with partners within the country and within the regions where countries are located, and then with partners outside those regions, such as Gavi the Vaccine Alliance. I would say one of the biggest pieces of work we’ve done in recent years has been to really push the importance of having regular campaigns of very high quality in countries where the routine system is just not strong enough. 

Why regular immunization campaigns?

Countries where they’re reaching 50 or 60 or 70 percent routine immunization coverage, the only way to really make sure that children are protected is to “catch them up” through regular campaigns. And those campaigns have to be timely, and they have to reach all the children that were missed. So that is a job in itself, just finding out where those children are. It involves a lot of support and planning. 

What makes the immunization campaign effective?

A lot of communication with communities right at the grassroots level. So families know. It’s like the circus is coming to town. The immunization team is coming to town. Get your kids immunized. And in those sorts of settings, generally, if everything’s done as it should be, then high coverage is usually reached because in the settings we’re talking about, people generally know about measles, and they know it’s bad and they get their kids vaccinated. 

Not the same as a high-income country…

It’s a far cry from what you might expect if you’re sitting in Canada or the U.S., where you have a pediatrician or family doctor in their office and they have a whole system for inviting kids and families in to get immunized. Rather than walking house to house in a village trying to find the children, it relies more on electronic means of knowing who the kids are. More countries are putting in more electronic type systems, like Pakistan is putting in a system so they can identify through their national electronic immunization record where kids are and follow up. That’s the future for countries everywhere, but many countries are still a long way off from having that kind of system in place. 

What about where vaccination rates for measles are actually declining because of vaccine hesitancy and concern about vaccination for measles?

I think the answers really vary depending on the local context. The general answer is you need trusted experts that understand the local context. And then they don’t necessarily have to be the world expert on a disease, but they need to be someone with credibility and authority in the community who understands where the hesitancy is coming from. That varies a lot.  

Then vaccine hesitancy comes from different sources?

What makes people hesitant depends a lot on the local context, the culture, the history of the program. If things have gone wrong in the past with other vaccines, then they may be concerned about measles vaccine as a result. We saw that a lot in outbreaks of measles following, for example, when the dengue vaccine was introduced. At one stage it caused issues and then people stopped immunizing for measles. Then there was a big measles outbreak and that actually in some ways solved the problem. It’s not the way we’d choose to solve the problem. But as soon as you have an outbreak, that’s often a fix for vaccine hesitancy and people step forward and get their kids protected, because they see what happens if they don’t.  

Is there no one-size-fits all approach to hesitancy?

It depends on the culture of the community that’s affected, and it depends on the issue that they’re worried about. Some have heard now discredited stories linking the measles vaccine and autism. Or they have a general issue with vaccines. It really has to be adapted. We’re kind of looking for single solutions when really they have to be developed in the local context with the communities that are affected and respecting the views of those communities and adapting the messages. Most parents want the same thing for their kids — they want them to be safe and healthy and grow up to be healthy adults.  

Does it take seeing the destruction of a disease to get people to change their minds?

Sometimes it’s about developing relationships with people who may say no today, but they may say yes tomorrow. We hear stories about kids who grow up and have never been vaccinated and when they come of age to make their own decisions, they make different decisions than their parents. And again, that’s often facilitated by having good relationships with their own health providers because that’s the trusted place they’ll go. We need to be in listening mode and understanding what the community is going through and why they’re feeling the way they are and try and address those issues where we can and meet them where they are. 

We hear a lot less about rubella than we hear about measles. Why is rubella such a devastating disease?

Rubella is a periodic epidemic disease, so it’s not front of mind. Unlike measles, it doesn’t come back every couple of years. A lot of people get infected, and then it goes away again for a while, and everyone sort of forgets about it.  

It’s a problem because if women are infected in early pregnancy, it can be absolutely devastating. Up to 90% of babies are affected by it if their mother is infected in early pregnancy. The impact is that the baby may die during the pregnancy. If they survive, the baby can be born with problems with almost every system in their body, including severe developmental delays, congenital cataracts, really devastating problems. And it’s something that can be prevented by a single shot. 

What is the global situation with rubella vaccination?

The reason I talk about measles and rubella together is because they come in the same syringe now. You don’t give rubella vaccine on its own. Every country that has achieved rubella elimination has sustained it, and it remains eliminated because rubella is not quite as infectious as measles. So far, one region — the Americas — has achieved rubella elimination. Gradually countries are achieving elimination thanks to the MMR vaccine. We’re getting closer and closer to the point where all countries could potentially eliminate rubella.  

What will it take to eliminate rubella?

Last year we got a big decision made by the World Health Organization’s Strategic Advisory Group of Experts to lift the remaining barrier to introducing rubella vaccine in every country in the world. A few big countries, Nigeria and the Democratic Republic of Congo, are going to be introducing rubella vaccine later this year. Those are two of the biggest countries in the African region. There are 13 countries that haven’t yet got their plans, but now they can plan to introduce the rubella vaccine. Once we’ve done that, then we can really start making strides towards eventually eradicating rubella, which would be an astonishing next step. It’s really the low-hanging fruit in immunization that we could feasibly eradicate rubella in our lifetimes, which we can’t say about many things. 

Will we ever be able to eliminate measles?

The history of elimination success shows it really requires very strong political will and solidarity between countries. If you look back at the story of smallpox, if you look at polio and you look at what we’ve achieved so far with measles and with rubella, countries were really concerned about making sure they didn’t let each other down. There was usually a very clear regional plan driven by a very charismatic person and by the support of all the countries in the region.  We know how to do it at a regional level, and I think the same is true at global level. You need to have that kind of coalition of countries everywhere with the support of global leadership and global agency to make things move in that direction.  

With rubella, we are heading in that direction. With measles it’s much more challenging because you can go backwards as well as forwards much more quickly. But it’s that idea of everybody coalescing around a shared goal and having countries buy in to the idea that this is something they want. In the meantime, we’re doing our part shining a light on measles and rubella, which really need our attention right now more than ever.