An improved vaccine for bacterial meningitis and bloodstream infections

June 28, 2019

Washington, DC - June 18, 2019 - Researchers have now developed a new vaccine, a native outer membrane vesicle (NOMV) vaccine, for meningitis and bloodstream infections caused by "meningococcal group B" bacteria. This will allow younger people to be vaccinated and will address several limitations of the current vaccinations. The research is published this week in mBio, a journal of the American Society for Microbiology.

"We developed the improved version of the vaccine by making several genetic changes to the strain of bacteria used to produce the vaccine, resulting in a broadly protective vaccine rather than a strain-specific vaccine," said Peter Beernink, Ph.D., Scientist at the Center for Immunobiology and Vaccine Development, Benioff Children's Hospital Oakland.

There are currently only two licensed vaccines for prevention of meningitis and bloodstream infections caused by "meningococcal group B" bacteria, which are only licensed for use in people age 10 years and older. Both vaccines contain a bacterial protein known as Factor H binding protein (FHbp), which can bind to a host protein known as Factor H (FH).  The licensed vaccines have several limitations, which include lack of effectiveness against some bacterial strains and low immune responses of infant humans.

The researchers immunized infant rhesus monkeys with the NOMV-FHbp vaccine, which induced higher levels of protective serum antibodies than a licensed vaccine against five of six bacterial strains tested.  Two macaques immunized with the licensed vaccine, which contains FHbp that binds macaque FH, developed antibodies to the host FH protein whereas none of the animals given the NOMV-FHbp vaccine or a negative control vaccine developed such antibodies.

The monkey antibody responses to the vaccines were measured in the laboratory based on the ability of serum antibodies to kill the bacteria in a test that is widely considered to predict protection in humans.  The sample sizes of animals were chosen such that the results are highly statistically significant.

"The experimental NOMV vaccine extends the approach of using outer membrane vesicle vaccines, which previously have been given to millions of persons during meningitis B epidemics in Norway, Cuba and New Zealand," said Beernink.

Thus, in a relevant infant non-human primate model, the NOMV-FHbp vaccine elicited higher levels of protective antibodies than the licensed vaccine and anti-FH antibodies in fewer animals. "This shows that the vaccine has the potential to be developed into a more broadly protective vaccine for humans, to extend coverage to infants and toddlers, which are the age groups among the highest risk of developing meningococcal disease, and to increase vaccine safety," said Beernink.
-end-
The work was performed by Peter Beernink, Dan Granoff and colleagues at UCSF Benioff Children's Hospital Oakland (California).  The work was funded by a research grant from the National Institute of Allergy and Infectious Diseases, National Institutes of Health.

The American Society for Microbiology is the largest single life science society, composed of more than 30,000 scientists and health professionals. ASM's mission is to promote and advance the microbial sciences.

ASM advances the microbial sciences through conferences, publications, certifications and educational opportunities. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.

American Society for Microbiology

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.