Dengue rewires immunity, shaping vaccine response

Dengue infection can ‘reprogram’ the body’s immune system, leaving a lasting genetic imprint that influences responses to future infections, a study [1] by Duke-NUS Medical School has found. The effect is not seen with vaccination, shedding light on why vaccines work better for people with prior dengue exposure.

The researchers analysed blood samples from volunteers in the US and Singapore who had received a two-dose dengue vaccine. They discovered that prior dengue infection created distinct patterns of gene activity in immune cells targeted by the virus. This long-term imprint, known as trained immunity, meant that vaccination triggered a stronger immune response in those previously infected.

“Our findings show that natural dengue infection leaves a lasting genetic imprint, resetting the immune system to a new baseline,” said Dr Eugenia Ong, Principal Research Scientist at Duke-NUS. “This may explain why second infections can be more severe.”

Professor Ooi Eng Eong, senior author, added: “Think of it as training for a sport - the immune system only gets a full workout from a natural infection. Vaccination alone isn’t enough to leave the same imprint.”

The study, published in Med, highlights why even imperfect vaccines can be used safely to prevent dengue and points the way toward developing more effective vaccines. As dengue continues to affect millions globally, these insights could help guide vaccine strategies and health policy.

More information online

1.    Dengue virus infection reprograms baseline innate immune gene expression published in Med