In the past few months, increased measles outbreaks have caused a sensation. In Europe, thousands of people had to be treated in the hospital in 2024 due to severe measles courses, 38 affected people died. The measles virus is also rampant in the United States, although the infectious disease there was already considered erotted. What is behind the measles return?
What are measles?
Measles are a viral disease that is considered a childhood disease, but can in principle affect all people. The cause is an RNA virus from the paramyxovirus family, which, in contrast to influenza or coronavirus, almost only occurs in humans. An infection with the measles viruses triggers characteristic red skin stains, which usually go for fever, headache, cough and runny nose. In severe cases, diarrhea and dehydration or inflammation of the lungs or the middle ear, which must be treated in the hospital, lead to.
The measles virus also has the ability to penetrate into the brain via nerve pathways and the blood-brain barrier. There, it can trigger inflammation of the meninges and the brain in around 0.1 percent of cases. This meningoencephalitis ends in ten to 20 percent of those affected, and brain damage and intellectual disabilities remain in another 20 to 30 percent of cases.
Every year, around 100,000 people die of measles such complications, as the World Health Organization WHO documented. In addition, measles infection can extinguish the immunogial liveliness even with a slight course. The immune system then forgets which pathogens have previously combated, so that those affected become more susceptible to other diseases for about a year.
How high is the risk of infection?
In the United States, in Europe and Central Asia, measles has been spreading worryingly for a few months, as different health authorities report. Around 127,000 measles cases were reported in the European region for 2024 – the highest number since 1997. At that time, around 216,000 cases were reported.
The reason for the spread: the pathogens are highly contagious for humans – far more contagious than most other virus infections – and transmit themselves where too few people are vaccinated. “A person with measles can infect between 12 and 18 unprotected people,” reports the Robert Koch Institute (RKI). The viruses are transmitted via the mouth or nose droplets as well as over the air.
In Germany, “only” 645 measles cases were reported for 2024. This means that the numbers in this country are still as high as in the past 20 years. However, spreading in Germany would also be quickly possible because there are regional vaccines here, for example in Baden-Württemberg and Saxony.
How well protects a measles vaccination?
Vaccines against measles viruses that protect vaccinated from an infection were introduced in Germany in 1971. With a unique dose, the effectiveness is 92 percent, in the two doses, which are mostly recommended for children, 98 to 99 percent. “Vaccination is the best protection against the virus,” emphasizes the WHO. It contains weakened measles viruses that can no longer multiply.
Toddlers in Germany usually receive this vaccin in combination with other vaccines against mumps and rubella (MMR vaccination). If the vaccination rate among the population is at least 95 percent, people who themselves cannot (yet) be vaccinated are indirectly protected. These include, for example, infants and toddlers under nine months.
At the beginning of the millennium, most European countries had reached high vaccination rates, whereupon the number of measles infections in Europe has dropped significantly until 2016. However, fewer parents have been vaccinating their children for several years, so that gaps in population protection have arisen. Since then, larger outbreaks have occurred, including increasingly serious illnesses, hospital stays and occasional deaths.
Why are too few people vaccinated?
Since 2020, there has been a vaccination light against measles for children in Germany who go to daycare or school. But because the Corona pandemic disturbed the vaccine routines, thousands of children still have a catch-up need for measles vaccination. Other children are not protected because their parents are afraid of vaccination damage. Serious side effects of vaccination occur much less frequently than severe symptoms in measles infection.
False messages also fold the fear of vaccination, according to which measles vaccination allegedly triggers autism or other diseases. However, that is not true. “There is no association between vaccination and the occurrence of a Crohn disease, an ulcerative colitis, of autism or a SSPE,” emphasizes the RKI with a view to chronic bowel diseases and the brain damage Sppe.