In an ‘online’ session organized this Tuesday by the Science Media Center, the focus was placed on the data provided by the Epidemiological Surveillance Network, which confirms 110 cases of measles so far in 2025, representing just over half of the total cases confirmed throughout last year (217).
According to López, this increase does not imply the loss of the «elimination status» that the World Health Organization (WHO) granted to Spain in 2016 after accrediting that there had been no endemic transmission of the virus in the country in the previous two years, a situation that has not changed to date.
The researcher pointed out that 41 of the 110 confirmed cases originate from an outbreak in the Basque Country, which has occurred within the community and has also impacted the hospital, an environment where transmission tends to be amplified. Likewise, she indicated that these infections, as usual, are occurring in adults.
«It is really rare that we have cases, as happens in countries around us where vaccination coverage is lower and (…) (the) most affected are the children because the vaccinations are worse than ours. Right now, we are dealing with a measles that is expected in a post-elimination context. It is generally affecting relatively susceptible age groups that could not have measles because there was no circulation of it and there were not sufficiently high vaccination coverage to protect them,» she explained.
VACCINATION COVERAGE
López specified that these susceptible groups due to low vaccination coverage include people born between 1978 and 1987, as reflected in the 2nd Seroprevalence Study published in 2020. «Previously, data indicated that those born in 1971 and later were the most susceptible (…), but the study data have shown that the cohorts between 1968 and 1977 show a seroprotection of over 98 percent and it is from those born between 78 and 87 who have slightly lower coverage. Those are the susceptible ones,» she emphasized.
In this regard, she added that it is «not expected» for measles to be transmitted in young children because they are a «well» vaccinated group. In the event that this situation occurs, she argued that it would be due to problems accessing the healthcare system or vaccine hesitancy, a factor that has been observed on a case-by-case basis in children from another country who have not been within the health system.
On the other hand, the pediatrician, spokesperson, and senior member of the Spanish Association of Vaccinology (AEV), Fernando Moraga-Llop, pointed out that, although the average percentage of administration of the first dose of the vaccine in Spain in 2023, the latest available data, reaches 97.8 percent, there are four communities that are at 95 percent, while in the second dose, a total of 11 autonomous communities are below this 95 percent.
«I think these figures, which are quite good or in some cases could be good, very good, should be taken with some caution in certain large cities. There, a study of vaccination coverage by neighborhoods, by areas, should be carried out, and one would realize that perhaps in an average vaccination coverage of 97 percent in an important city, there is an area (of that city) that has a coverage of 50 percent,» he warned.
The spokesperson for the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), María del Mar Tomás, agreed with Moraga-Llop on the fact that there are specific areas where vaccination rates are insufficient. «That’s why the virus in these areas is finding the capacity to replicate and spread and cause small outbreaks, which are small, but in the end, they add up,» she noted.
On the other hand, Noemí López reported that 34 of the confirmed cases of measles this year are imported from other countries and emphasized that it is not only citizens who migrate to Spain but also tourists who bring the virus. «Measles knows no borders, it circulates with the movement of people,» she stressed.
Thus, she emphasized «not to stigmatize» these groups or «blame» them for the infection, but rather to focus on «identifying susceptible populations» to work with them appropriately and to «intervene in public health.» As she mentioned, the autonomous communities are already working in this direction. «Instead of blaming, focus more on access to the health system,» she highlighted.
HOW TO REDUCE POTENTIAL CASES
In order to reduce potential cases among susceptible groups, López explained that people born from 1978 onwards are asked in medical consultations if they have been vaccinated against measles or if they have had it, and in case of a negative or doubtful answer, vaccination is offered to them. Likewise, she pointed out that vaccination is also offered to international travelers, regardless of whether they travel to a country where the virus is circulating or not.
«As a precaution for all people born after 1970, I would ask the question, because from 1970, the measles virus was circulating, but it was already starting to decrease,» added Fernando Moraga-Llop.
Along with this, María del Mar Tomás advocated for early laboratory diagnostics in case of any clinical suspicion of a susceptible patient, as well as genomic characterization, with the aim of preventing possible spread and the occurrence of an outbreak.
With all this, the three experts agreed that there is «no danger» at present of losing the measles elimination status granted by the WHO, as long as vaccination coverage, early diagnosis, and epidemiological studies of contacts continue. Nevertheless, they mentioned that the population and healthcare professionals should remain «alert,» especially regarding susceptible groups.
