Healthcare-associated infections (HAI) pose a significant and growing concern for individuals who get admitted to hospitals.
Adding to global efforts to combat increasingly resilient pathogens, researchers at the University of Southern California (USC) aspire to lead the charge in this battle with the help of a newly developed vaccine.
While some in the medical domain are looking to make stronger antibiotics, the USC researchers are working on a vaccine that will target multiple hospital superbugs causing these infections.
A study published in Science Translational Medicine highlights the use of an experimental protein-free vaccine that could possibly protect us against a wide range of hospital-acquired infections.
Multiple bugs in the crossfire
The study on mouse models demonstrates that a single dose of the vaccine activated immune cells to an extraordinarily strong level, offering rapid protection against eight distinct bacterial and fungal species.
The experimental vaccine could be used for multiple species of superbugs such as Methicillin-resistant Staphylococcus aureus (MRSA), E. coli, Enterococcus faecalis, Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. This eliminates the need for making a vaccine for each pathogen species.
“In mice the effect lasts around four weeks. In humans, it may last somewhat longer, may be [for] weeks to months. This duration is long enough to prevent hospital acquired infections, as most individuals stay in the hospital for not more than a week,” says Dr Brad Spellberg, senior author of the paper and chief medical officer at the USC-affiliated Los Angeles General Medical Centre.
Dr Spellberg hopes the new therapy will result in reduced reliance on antibiotics to fight healthcare associated infections.
“The goal of a vaccine is to prevent infections from happening in the first place. If we can stop people from getting these infections, there will be less need for antibiotics, [and this] will lessen the selective pressure that drives antibiotic resistance,” Spellberg tells Happiest Health.
A first vaccine of its kind
If successful, this vaccine could be the first of its kind, as there is currently no vaccine approved by the US Food and Drug Administration for drug-resistant pathogens.
The infections caused by these superbugs are common in hospitals, where they spread through contaminated surfaces, equipment such as catheters and person to person contact. The risk of these infections can either cause already unwell individuals to stay longer in hospitals or in worst cases, be fatal.
The possible use of a vaccine opens a new road for the treatment of HAI whose numbers are steadily rising globally. According to a recently published study, every year around 136 million hospital-associated infections occur that are resistant to antibiotics.
Out of these, nine million cases are from India.
An alert for the immune system
The new vaccine works much differently from a traditional one. Conventional vaccines stimulate lymphocyte-mediated immunity that lasts for years, says Dr Spellberg, whereas this vaccine stimulates trained immunity for a short term.
What it does is activate the pathogen-eating cells of the immune system known as macrophages to engulf bacteria or fungi which enter the body. Spellberg likens the vaccine’s action to that of the “Incredible Hulk”, superhero of a 2008 American film, lying in wait and serving as an early warning system for the immune system to act immediately on villainous superbugs about to cause severe infections.
Work in progress
The lead author of the study, USC doctoral student Jun Yan, says “If this vaccine is effective in patients, we can greatly reduce the number of infections and antibiotics usage in hospitals. As a result, we might be able to reduce emergence of new antibiotic resistance.”
Future work will explore the safety of the experimental vaccine post-infection. Additionally, they will also need to design a clinical trial and get it approved by the FDA.
“A clinical trial is needed before FDA approval [of the vaccine]. We are moving forward to start phase I clinical trial,” says Yan.
