Giving rotavirus vaccine at birth benefits gut bacteria

Babies who receive a RV3-BB rotavirus vaccine at birth appear to show higher levels of good bacteria in their gut, better protecting them against infection during the first weeks of life, according to a new study led by the Murdoch Children’s Research Institute (MCRI) and published in the journal Nature Communications. The discovery should help to pave the way for researchers to improve the health outcomes of young children with severe rotavirus gastroenteritis, especially those living in low-income countries.

The gut microbiome — ie, the bacteria, viruses and fungi found in a healthy gut — assists with digestion and regulation of the immune system. At birth the gut microbiome is relatively immature, providing a unique time point where the microbiome presents less of a challenge to the uptake of orally administered vaccines such as RV3-BB.

The MCRI Enteric Disease research group, led by Professor Julie Bines, developed the RV3-BB vaccine, which has been proven to be safe and effective in clinical trials in Australia, New Zealand, Indonesia and Malawi. Bines said that understanding the interaction between gut microbiome and the protection provided by the vaccine is key to informing new dosing schedule options within national immunisation programs.

For the study, stool samples from almost 300 babies in Malawi and Indonesia were collected with all receiving three doses of the RV3-BB vaccine either in a neonatal schedule (first dose within 0–5 days after birth) or an infant schedule (first dose from 6–8 weeks of age). The samples were analysed using advanced sequencing techniques and bioinformatics tools.

The research found that those babies who had had the vaccine from birth had higher levels of ‘good’ bacteria in their gut microbiome than those vaccinated with the first dose at 6–8 weeks of age following the routine immunisation schedule. MCRI’s Dr Josef Wagner said the results showed the timing of the first dose of RV3-BB is important to optimise vaccine response.

“Our findings suggest the RV3-BB vaccine, when given at birth, may help shape the early gut microbiome in a way that improves the body’s response to the vaccine,” he said. “Importantly, administering the vaccine at birth may provide a window of opportunity to target the first dose, which could improve vaccine uptake and provide early protection.”

Bines said the study also found the response to the RV3-BB vaccine when given from birth was linked to the balance of both good and bad bacteria in the gut microbiome.

“A strong vaccine response was greater in babies with a higher proportion of good bacteria, while it was lower in babies with more potential disease-causing bacteria,” she said. This indicates that providing the vaccine as soon as possible after birth, before babies are exposed to bad bacteria in their environment, may help avoid the challenges to the response of oral rotavirus vaccines, particularly in low-income countries.

“Babies who received the RV3-BB from birth also sustained a healthy gut microbiome for much longer compared to those who didn’t receive the vaccine,” Bines said. “This further suggests the vaccine may have a positive effect on the development of the early gut microbiome.”

Image credit: iStock.com/chameleonseye