vaccines

Global vaccination efforts have achieved an 88% reduction in measles deaths between 2000 and 2024, and nearly 59 million lives have been saved by the vaccine since the beginning of the century, according to a new report from the World Health Organization (WHO). However, an estimated 95,000 people—mostly children under the age of five—died from measles in 2024, a disease that could be prevented with an effective, low-cost vaccine. Although the death toll is one of the lowest in this period, measles cases are on the rise worldwide, with an estimated 11 million infections in 2024, nearly 800,000 more than pre-pandemic levels in 2019. Specifically, cases in Europe increased by 47% between 2019 and 2024.

Two meta-analyses conducted by the Cochrane Collaboration confirm that vaccination against human papillomavirus (HPV) prevents cervical cancer. Both articles bring together the results of 60 clinical trials and 225 studies involving more than 130 million people worldwide. According to Cochrane's press release, the result “is strong and consistent evidence” that vaccines against this virus are effective in preventing cervical cancer and precancerous changes, especially when given to young people before they are exposed to the virus. The reviews also confirm that HPV vaccines usually cause only mild and temporary side effects, such as pain in the arm. 

A clinical trial funded by Pfizer has tested a new influenza vaccine based on messenger RNA (mRNA). The phase 3 trial included more than 18,000 people aged 18 to 64, half of whom received the new compound and the other half a conventional vaccine. The results indicate that the mRNA vaccine was more effective, but it also caused more adverse reactions: for example, 5.6% of the volunteers who received it developed a fever, compared to 1.7% of those who received the conventional vaccine. The study is published in the journal NEJM. 

The Pfizer-BioNTech COVID-19 vaccine has been linked to rare cases of heart inflammation in children and young people. The largest study of these risks in children, published in The Lancet Child & Adolescent Health, concluded that receiving the vaccine is associated with a risk of developing myocarditis or pericarditis within six months of 0.85 additional cases per 100,000 vaccinated children; while after COVID-19 infection, the risk is 2.24 additional cases per 100,000. The study used data from 98% of the British population under the age of 18 (almost 14 million) between January 2020 and December 2022.

Childhood vaccination rates have increased modestly worldwide in 2024, without reaching their pre-COVID-19 pandemic levels, according to data from the WHO and UNICEF. For example, global measles vaccination coverage rose by one percentage point from the previous year, reaching 84% of girls and boys who had received one dose in 2024, compared to 86% in 2019.

With the summer holidays approaching, questions arise about how to prepare for trips to other countries, including health recommendations. In this guide, we explain the basics of how to protect yourself and others.

Between 1980 and 2023, childhood vaccination rates against diphtheria, tetanus, whooping cough, measles, polio and tuberculosis doubled worldwide, according to a study published in The Lancet. However, this increase slowed in many countries between 2010 and 2019; during this period, measles vaccination declined in half of all countries.

Gonorrhoea is the second most common sexually transmitted disease in the world, with 80 million cases each year. There is no effective vaccine, and the bacteria responsible are becoming resistant to common antibiotics. Some studies have suggested that the meningococcal B vaccine, a unrelated bacterium, may offer partial protection against gonorrhoea. Now, an Italian team has identified 17 antibodies that could explain this cross-immunity, which, according to the authors, could be used to develop treatments and vaccines. The results are published in the journal Science Translational Medicine.

According to the results of a phase 2 trial, an oral norovirus vaccine generated a strong mucosal immune response and even reduced viral shedding in vaccinated volunteers. Signs of the vaccine's efficacy support its potential to address the lack of safe and reliable vaccines against this virus, which is a major cause of gastrointestinal infections worldwide. The results were published today in the journal Science Translational 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.