Study findings suggest way to improve common childhood vaccine effectiveness

A newly published study suggests the effectiveness of a common childhood vaccine can be improved by altering intestinal bacteria.

More than 200,000 children under the age of five die annually from rotavirus. The disease is the leading cause of diarrhea-related death in children worldwide. Though rotavirus vaccines are widely used and can protect against rotavirus disease, they are significantly less effective in low-income countries.

A study published in Cell Host & Microbe today suggests that altering the intestinal bacteria, also referred to as the microbiome, could boost immunity from the rotavirus vaccine. The work was led by Dr. Vanessa Harris, Assistant Professor, Department of Global Health at the Amsterdam UMC-Amsterdam Institute for Global Health and Development alongside Drs. Bastiaan Haak, and Professor Joost Wiersinga, Department of Infectious Diseases, Amsterdam UMC.

The Effect of antibiotic-mediated microbiome modulation on rotavirus vaccine immunogenicity: a human, randomized-control proof-of-concept trial evaluated 63 adult participants who were provided with either no antibiotics, broad-spectrum antibiotics or narrow-spectrum antibiotics and then received the rotavirus vaccine.

The findings demonstrated that antibiotics seemed to improve immune responses to the vaccine, especially when participants received narrow spectrum antibiotics.

While the results from this study are limited since rotavirus is a childhood disease and the microbiome of infants and children is different in adults, the researchers believe their microbiome/vaccine response theory deserves further study.

“I think there is a fascinating interplay between the bacteria and viruses in our intestines and our intestinal immune system ,” says Harris. “All microbiota in the gut, including bacteria, fungi, and viruses, have evolved together for so long, it is very likely viruses exploit bacteria or immune responses in the gut to their advantage. Perhaps certain bacteria help the rotavirus replicate or antibiotics alter bacteria and thereby trigger immune responses that are favorable or unfavorable for a virus”.

The team believes that understanding that triangulation between bacteria, virus and the human immune system has potential for vaccinology and can lead to important uses of the microbiome which have not been realized to date.

Harris emphasizes that this work does not advocate for antibiotic use in infants or children to boost rotavirus responses. Instead, the researchers view these results as a starting point with great potential for altering the microbiome to improve vaccine performance and ultimately better protect children in low-income settings from rotavirus, which continues to be a life-threatening disease.

Rotavirus was first discovered in 1973 by the Australian researcher Ruth Bishop. Prior to the development of the vaccine, rotavirus killed nearly 500,000 children and infants a year.

For more information on Dr. Harris’s research, visit AIGHD’s website.