Revelation on the Epidemic of the Century

21 août 2025

A team of researchers, led by the Institut Pasteur, is currently investigating the largest whooping cough epidemic recorded in France in at least a quarter of a century. Sylvain Brisse, a renowned researcher, and his team have undertaken the sequencing of nearly 70 Bordetella pertussis isolates collected between January and mid-2024. This meticulous work aims to better understand the disease’s transmission dynamics and to generate hypotheses regarding the factors contributing to its resurgence.

The findings of this research have highlighted significant evolution in certain strains of the bacteria responsible for whooping cough. In particular, the team discovered that several strains have lost pertactin, a key component of the acellular vaccines currently in use. This genetic modification could be one of the reasons for the reduced effectiveness of modern vaccines, a problem that researchers are paying close attention to. This bacterial adaptation raises concerns about the ability of existing vaccines to curb the disease’s spread.

One major issue identified by the study concerns the limited duration of immunity provided by the vaccine. Indeed, vaccine protection gradually declines after five to ten years, leaving a large portion of the population especially adolescents and adults more vulnerable to infection. These groups, often overlooked in booster campaigns, play a significant role in disease transmission. Sylvain Brisse and his colleagues therefore emphasize the need to rethink vaccination strategies, particularly by strengthening booster programs to better protect these populations and, by extension, the broader community.

The vulnerability of infants is another major concern. Babies, who cannot be vaccinated before the age of two months, are particularly susceptible to severe forms of whooping cough. In response to this, the researchers highlight the importance of promoting adult vaccination, particularly among pregnant women. This approach not only protects infants directly but also helps create a more effective herd immunity barrier.

By leveraging advanced genetic analyses and an in-depth study of disease spread, Sylvain Brisse’s team proposes essential strategies for adjusting vaccination policies in France. This work could prove crucial in preventing future whooping cough epidemics by ensuring that the most vulnerable populations are effectively protected. In summary, this study provides an enriched understanding of whooping cough, offering public health authorities valuable tools to better combat a disease that, despite vaccination progress, continues to pose a significant public health challenge.