Marvelous Microbes Round-Up

Stephanie Swift

An experimental TB vaccine identifies a cool new way to boost immune protection

Researchers from Canada tested out two new inhaled vaccines against adult tuberculosis, based on adenovirus or vesicular stomatitis virus. While both vaccines generated similar levels of adaptive immunity, only the adenovirus vaccine was also able to robustly activate innate immunity. Innate immunity exists in a state of constant readiness to repel pathogenic invaders, while adaptive immunity requires stimulation, activation and expansion before it can be fully engaged.

Most experimental immunization strategies against TB are specifically designed to stimulate adaptive immunity, with little thought of the innate immune system. Yet the fact that we still don’t have any feasible TB vaccine candidates suggests we should probably stop looking at vaccine design in such a blinkered way. Since this research shows that dual immune stimulation enhances anti-microbial effects and confers better protection against M.tb bacteria, it might be a useful insight for the future design of vaccines.


Yes, you should get the seasonal flu vaccine!

The Centers for Disease Control and Prevention in the USA has come up with a new way to model how their influenza vaccination program directly impacts the American healthcare system. In the USA, everyone over the age of 6 months is advised to get vaccinated, making it the only country in the world with a universal flu immunization strategy (most countries only recommend that the very young, the very old or those at high risk be vaccinated).

They found that vaccination prevented up to 5.8 million cases of influenza infection, and helped keep almost 13,000 people out of hospital for influenza-induced illness over a 6-year period. People getting vaccinated lowered burdens of disease, and received a substantial annual health benefit.


Taking public transport doesn’t increase your risk of catching the flu

Buses, coaches and trains are commonly thought of as perfect places to pick up an infection, packed full of warm, moist human bodies and recirculated air. But in fact, research from the London School of Hygiene and Tropical Medicine presented at the Cheltenham Science Festival indicates that taking public transport doesn’t change your risk of getting infected with influenza virus. One theory to explain this is that taking the grimy bus strengthens your immune shield and makes it harder for germs to take hold.


Silver boosts the effectiveness of antibiotics

The speedy rate at which pathogenic bacteria are evolving resistance to commonly-used antibiotics is becoming a huge healthcare problem. Combining defunct antibiotics with quirky different compounds – such as the anti-diahorrea drug, loperamide – is fast becoming an intriguing new strategy to boost our anti-bacterial arsenal.

Researchers have now discovered that silver, a potent anti-microbial in its own right, makes bacteria hyper-permeable and allows previously useless antibiotics to punch through the bug’s defenses. This research is particularly exciting since it worked against Gram-negative bacteria, which are notoriously difficult to kill due to their sturdy biological architecture – they are surrounded by a thick, resistant membrane that drugs have difficulties penetrating.


Why bad primary infections lead to worse secondary infections

People recovering from the flu have a really hard time fighting off secondary infections, like bacterial pneumonia. These immune difficulties have now been related to the vast amounts of tissue damage each pathogen wreaks, rather than inflammation or the spread of these organisms throughout the body.
Happily, therapeutic administration of a protein that stabilizes damaged tissues can improve the resolution of disease, and might represent a feasible new treatment strategy.