Gut Microbiota Modulates Rotavirus Vaccine Effectiveness

Scientists at Georgia State University's Institute for Biomedical Sciences have shown that some gut flora can reduce the effectiveness of the rotavirus vaccine.

The results, which were led by Drs. Vu L. Ngo and Andrew T. Gewirtz published in the journal Cellular and Molecular Gastroenterology and Hepatology, show that gut microbiota that is, the trillions of bacteria that reside in an individual's gut can affect a person's response to the rotavirus vaccine and occasionally leave children susceptible to severe illness and rotavirus infection even after receiving vaccinations.

Rotavirus is a virus that causes severe diarrhea, vomiting, fever, and abdominal pain. It is easily transmitted among newborns and young children. Hospitalization may be necessary for children with rotavirus sickness who become dehydrated. In many low-income nations, rotavirus vaccinations are not as successful as they could be, but they have shown to be very effective at protecting children in the US and Europe.

Rotavirus vaccines are live, attenuated viruses that are given orally and must infect the intestine of their host to produce a protective immunity. Since no two people receive the same level of protection from rotavirus vaccines, the researchers theorized that the effectiveness of rotavirus vaccines depends on the makeup of the gut microbiota, that the vaccine must infect.

In this work, mice receiving microbial transplants from children with high or low rotavirus vaccine responsiveness were used to examine the impact of human microbiomes on rotavirus vaccination.

They discovered that mice who received microbial transplants from people who responded well to the rotavirus vaccine produced robust anti-rotavirus antibodies and excreted a lot of rotavirus antigens.

Mice that were given microbial transplants from children who had not reacted to rotavirus immunization, on the other hand, showed just a little rise in rotavirus antibodies after vaccination and were therefore still vulnerable to rotavirus challenge.

DNA sequencing analysis of the microbiomes revealed the presence of Clostridium perfringens, a bacterium that can occasionally cause overt sickness but can also exist in some humans and animals without producing disease.

Mice were given oral cultured Candida perfringens, which partially replicated the characteristics of non-responders to the rotavirus vaccine. A reanalysis of published data revealed a weak correlation between children's C. perfringens abundance and failure of the rotavirus vaccine.

The researchers concluded that the composition of the microbiota affects the effectiveness of the rotavirus vaccination and that C. perfringens is one, possibly several, examples of human microbiota that can contribute to the failure of the vaccine.

Our findings reflect that C. perfringen may be one of a panel of microbes, including bacteria and viruses, that can impact infection of and, consequently, immune responses elicited by rotavirus vaccine viruses.”

Andrew T. Gewirtz, Georgia State University