Nav: Home

Typhoid vaccine may protect against other infections

February 27, 2019

New research by the University of Liverpool and Liverpool School of Tropical Medicine shows that vaccination with weakened strains of Salmonella may also protect against other infections.

The researchers hope that the findings could impact vaccination strategy in the developing world, where infectious diseases are common and where broader protection could potentially save many lives.

Typhoid fever is a bacterial bloodstream infection caused by Salmonella Typhi that is estimated to affect between 11-18 million people and cause between than 128,000-190,000 deaths annually worldwide.

Published in the journal Science Advances, a new experimental study presents promising first data on the 'non-specific' immune response triggered by the live oral typhoid vaccine Ty21a.

"Live-attenuated Salmonella vaccines are low-cost, well-tolerated and easily administered. These vaccines could potentially be included in global vaccination programmes, not just for their impact on Salmonella, but also for their off-target, non-specific beneficial effects," says lead author Dr Shaun Pennington from the Liverpool School of Tropical Medicine.

Previous evidence has suggested that some live-attenuated vaccines, such as those for measles and polio, can stimulate the human immune system to generate a wider protective response and lower all-cause mortality. In order to investigate whether Salmonella vaccines might offer similar protection, the researchers vaccinated a small group 16 healthy adults in the UK with the Ty21a vaccine and studied its impact on their immune system over the course of six months.

They looked at immune responses targeting Salmonella as well as those targeting a range of other pathogens. The changes they observed to levels of infection-fighting white blood cells (monocytes) and immune system messengers (cytokines) suggest that Ty21a can strengthen the immune response against subsequent, unrelated infections.

"The next step is to observe whether these responses also occur in children in low-income settings where their impact would be greatest. We'd like to conduct further clinical studies, where we will be able to assess the wider impact of our observations in conferring protection against other common infections, not just Salmonella," says Professor Melita Gordon from the University of Liverpool and Malawi-Liverpool-Wellcome Trust Clinical Research Programme, who was the study's principal investigator.

The researchers add that the ability to manipulate live-attenuated Salmonella so that they express components of other pathogens could make their findings particularly exciting for future 'vector vaccine' design.

"Salmonella vector vaccines could provide Salmonella-specific protection, vectored-pathogen protection and non-specific protection, making live-attenuated Salmonella a hugely powerful 'triple threat' tool for global vaccine development," adds Professor Gordon.

The paper 'Nonspecific effects of oral vaccination with live-attenuated Salmonella Typhi strain Ty21a' is published in Science Advances.
-end-


University of Liverpool

Related Immune System Articles:

The immune system may explain skepticism towards immigrants
There is a strong correlation between our fear of infection and our skepticism towards immigrants.
New insights on how pathogens escape the immune system
The bacterium Salmonella enterica causes gastroenteritis in humans and is one of the leading causes of food-borne infectious diseases.
Understanding how HIV evades the immune system
Monash University (Australia) and Cardiff University (UK) researchers have come a step further in understanding how the human immunodeficiency virus (HIV) evades the immune system.
Carbs during workouts help immune system recovery
Eating carbohydrates during intense exercise helps to minimise exercise-induced immune disturbances and can aid the body's recovery, QUT research has found.
A new model for activation of the immune system
By studying a large protein (the C1 protein) with X-rays and electron microscopy, researchers from Aarhus University in Denmark have established a new model for how an important part of the innate immune system is activated.
Guards of the human immune system unraveled
Dendritic cells represent an important component of the immune system: they recognize and engulf invaders, which subsequently triggers a pathogen-specific immune response.
How our immune system targets TB
Researchers have seen, for the very first time, how the human immune system recognizes tuberculosis (TB).
How a fungus inhibits the immune system of plants
A newly discovered protein from a fungus is able to suppress the innate immune system of plants.
A new view of the immune system
Pathogen epitopes are fragments of bacterial or viral proteins. Nearly a third of all existing human epitopes consist of two different fragments.
TB tricks the body's immune system to allow it to spread
Tuberculosis tricks the immune system into attacking the body's lung tissue so the bacteria are allowed to spread to other people, new research from the University of Southampton suggests.

Related Immune System Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...