Measles cases up 3000% in Europe in 2023

Top health officials have expressed concern over a significant surge in global cases of measles. Infections have been growing at an alarming rate since 2022 and the World Health Organisation and the Centers for Disease Control and Prevention in the United States say that millions of children are vulnerable to the potentially fatal disease. Our regular host and Cambridge University virologist, Dr Chris Smith, has the story...

Chris - Measles is a really horrible infection and it's probably one of the most infectious diseases that we know about. Most people have heard of the 'R value.' This is the number of people that each infectious case of a disease causes, how many people you give your illness to. And for flu and for COVID, it's 2 or 3. For measles, that number is 20. So it's extremely infectious, which means it spreads incredibly rapidly when you get a case of this. It has a short incubation period of a week or two, and people begin to feel unwell about a week before they get the rash. And they have this bright florid red rash all over their body for up to a week. And then they get better. And the problem with measles is that not only is it a really nasty infection when you have it - very high fevers, sore eyes, bad cough, and in some instances it also causes inflammation of the nervous system up to years later. But the damage doesn't stop there because it also has this bizarre effect of wiping clean your immune slate. It basically introduces immune amnesia. So if you look at someone who's been infected with measles, their immune system has forgotten how to fight off all the things that you've spent the previous part of your life learning to combat and becoming immune to, so you can then start to catch loads of stuff all over again. And that means that you have to live with the legacy, not just of having had a bad dose of measles, but catching things you thought you'd consigned to immune history. So it really is a nasty infection. And around the world, maybe as many as 150,000 people die of this every single year. It's not to be taken lightly.

Will - And the WHO is saying that there's been a 30-fold rise of measle cases in 2023 in the European region. What is behind such a dramatic rise in cases?

Chris - The WHO actually went further than that. Hans Kluge, who's the director of the European region of the WHO, points out that there've been a 30-fold rise, but 30,000 cases of measles, of which 21,000 have led to hospitalisation. And most of those have been in young children, 80% of them are in kids. And they attribute this really big surge recently, which we've also seen here in the UK. We've seen an increase of hundreds of percent in cases in the last year or so. We attribute this chiefly to a reduction in vaccine uptake. People are not vaccinating at a sufficiently high rate to stop the disease transmitting. Measles is incredibly infectious, which means you have to have very high levels of immunity in the population to reduce the chances that someone who's got measles can run into someone who can catch measles and maintain a chain of transmission. And that's herd immunity. And unless 95% of people are immune to measles in a population, it can still spread. And because our vaccine uptake rates have, across the world, sagged considerably. And in some parts of the UK sagged to about 60 to 65%, well down on the 95% we need, this is why we're now seeing increases in cases and a high likelihood we're going to get big outbreaks. And when you couple that to the fact that there's also a resumption in global travel off the back of COVID, we are now brewing up a perfect storm where we've got cases rising, people moving around the planet with measles and they're landing in an area where the outbreak can take root. And that's what's got people worried.

Will - We were sitting here maybe less than a few months ago in this exact same position talking about chickenpox and the need for a push for vaccinations. It seems like we're on almost a carousel wheel of diseases spiking. And you say it's obviously due to a lack of vaccination. Are the doctors having to counter the misinformation behind this sort of anti-vax movement as well?

Chris - We are not sure exactly why vaccine uptake rates have dropped, but there are probably a number of factors. One factor is that people are perhaps having vaccine fatigue off the back of COVID. The second factor is that when you look at who is not vaccinating, it's not a comprehensive thing across the populations of the world. In places like London, it's specific parts of London and specific communities. And this means there may well be misinformation, there may well be a lack of information in those communities that mean that people are not doing the things that other parts of the world have been and should be doing. And also the populations are quite mobile. We are seeing this in communities that tend to come and go, or are newcomers to a territory or a country. So they don't necessarily come from areas where there has been good vaccine uptake. And then there's the disruption caused by the pandemic, where some vaccine processes and procedures fell to the wayside in order to combat COVID. And people missed the boat and they haven't gone back and caught up. And all of that is adding up to a reduction in vaccine uptake, which is now leading to many, many people. I mean, we're talking about outbreaks in London of as many as a hundred thousand people if it really took off because there's so many people in one particular geography all in contact with each other, which means you could get an explosive outbreak. And this is probably why we are seeing a movement across the world of numbers in the way we are.

Will - So we've got, unfortunately, immovable things like population density, but also very real things you can do like getting vaccines. Is there any advice out there as to what you'd give to parents that they can do to protect their children from measles?

Chris - Best piece of advice anyone can offer is that vaccines are really, really effective. But you've got to have them. And they're really effective at any age. So even if you didn't have your MMR vaccine as a kiddy, it's normally given around one year of age and then there's another dose given just before you start school. Even if you've missed that cycle of immunisation, you can go back and have that at any point in your life. So if you think you might be vulnerable to measles, or your children haven't been vaccinated, or they missed a dose, please go and get a dose of MMR. This will stop you catching measles and stop you passing it on to somebody else.