Ignacio J. Molina Pineda

Measles cases in Europe and Central Asia fell in 2025 compared with 2024, according to preliminary data reported by 53 countries in the World Health Organization (WHO) European Region. This decline aligns with the preliminary figures published this week by the European Centre for Disease Prevention and Control (ECDC). According to the WHO, countries in Europe and Central Asia reported 33,998 measles cases in 2025, representing a decrease of nearly 75 % compared with the 127,412 cases recorded in 2024. In Spain, however, the number of cases has increased, as shown by data from the Carlos III Health Institute. A few weeks ago, the WHO announced that Spain had lost its measles-free status.

An international team trained 85 people to activate a part of the brain associated with reward and positive expectations, after which they received a hepatitis B vaccine. Overall, those who learned to maintain greater activity in this area showed a greater increase in antibody levels after immunization. According to the authors, the results “suggest that positive thinking could help the brain strengthen the immune system in a non-invasive way.” The work is published in Nature Medicine. 

An Australian team has conducted a study involving mice and humans that suggests that vaccine boosters would be more effective if administered in the same arm as the previous dose, at least in the short term. However, other recent research has pointed in the opposite direction. The results are published in the journal Cell.

According to a new study published in Science, a machine learning-based artificial intelligence (AI) system - called Mal-ID - can decipher an individual's history of infections and diseases in the immune system. The authors say this provides a powerful tool with the potential to accurately diagnose autoimmune disorders, viral infections and vaccine responses.

Toledo and Alicante are suffering the first outbreaks of measles recorded in Spain since the pandemic, El País reported today. In total, 15 cases have been confirmed since 1 January, of which seven are imported and eight autochthonous.

A study has analysed more than 100 environmental factors and their impact on the immune response. After studying about a thousand volunteers, its conclusions are that smoking is the factor that causes the most alterations in defences. While some changes are transient, others may remain for years after quitting. The results are published in the journal Nature.

The Karolinska Institute has awarded the Nobel Prize in Medicine or Physiology to Katalin Karikó and Drew Weissman for their groundbreaking discoveries, which have radically changed our understanding of how mRNA interacts with our immune system, and made it possible to develop vaccines at unprecedented speed during the covid-19 pandemic.

In an interview with US television FOX News, FBI Director Christopher Wray said that, according to his office's assessment, "it is likely that the origin of the coronavirus pandemic was a leak from a laboratory in Wuhan, China". These statements follow media reports of a US Department of Energy report, accessed by the Wall Street Journal, that would also support "with low confidence" the leak hypothesis. Even so, a spokesman for the US National Security Council told AP that there is "no consensus" among intelligence agencies on the issue.

During Pfizer's appearance before the European Parliament this week, a company executive responded to the question of whether "Pfizer's vaccine was tested to stop transmission of the virus (SARS-CoV-2) before going to market" by saying "no".

To estimate the effectiveness of two or three doses of vaccines against covid-19 infection and hospitalisation, researchers in Denmark conducted a study of all previously uninfected Danish residents aged 12 years and older. The conclusion of the research, which is published in PLOS Medicine, is that a third dose provided greater protection against infection and hospitalisation with omicron than two vaccines.