One-two punch: flu treatment protects lungs & minimises pneumonia

A new flu treatment could drastically reduce one of flu’s deadliest complications – bacterial pneumonia – by helping the lungs defend themselves, rather than targeting the virus directly.

Influenza specialist Associate Professor Michelle Tate’s latest research has shown that a synthetic peptide called LAT9997, delivered directly into the airway, can protect against both severe flu and the secondary bacterial infections that frequently follow it — often with fatal consequences.

The pre-clinical study, published in Mucosal Immunology, found that just two doses administered into the lungs after influenza infection, were enough to dramatically limit lung damage, with no further treatment needed.

A/Prof Tate says this type of treatment shows huge advantages over existing anti-viral treatments.

How this flu treatment works to prevent pneumonia

When someone gets flu, the virus damages the lungs’ protective lining and disrupts the immune system, leaving the door open for bacteria to take hold. This secondary pneumonia is often what kills vulnerable people.

LAT9997, which is derived from a naturally occurring fragment of human growth hormone, works on two fronts:

1. It blocks a pathway that the influenza virus hijacks to spread through lung cells — slowing the infection at its source.
2. It also helps the lung maintain its protective lining and rebalances the immune response, preventing the inflammatory overreaction that leaves patients vulnerable to bacterial infection.

Delivered directly into the airway, the treatment is designed to act locally in the lungs without any observed side effects — and has the potential to be self-administered, making it practical for early use at home.

“This is significant because no therapies currently exist to prevent post-flu bacterial pneumonia, which causes substantial death and illness globally,” A/Prof Tate said.

Two doses, lasting protection

Because it works on the body’s own immune system rather than targeting the virus, it is also unlikely to drive resistance — a growing problem with conventional antivirals and antibiotics — and could potentially offer protection against other respiratory infections.

The researchers believe this makes it particularly promising for older adults, who are most at risk of severe flu and its complications.

A/Prof Tate and her team have been working with Lateral Pharma to develop LAT9997 and its related parent peptide further, with the aim of progressing to clinical trials.

Lead researcher Dr Alison West said one of the most striking findings was just how briefly the treatment needed to be given to produce lasting protection.

“We’ve found that this approach not only reduces viral replication, it also limits the inflammation that can cause serious damage in people with influenza,” Dr West said.

“The advantages LAT9997 has over antivirals are that it’s potent and fast-acting; just two doses early in the infection provided long-lasting protection.” she said.