Combined vaccines show promise

Researchers find combination of immune cells and antibodies that may lead to a universal flu vaccine

Every year, people line up at local doctors’ offices to wait for the slight pinch of a shot that will allow them to avoid becoming one of the 36,000 Americans annually who dies from seasonal influenza, according to the Center for Disease Control.

A flu shot is made by growing the flu virus strain in eggs, after which it is cleaved off and used for the vaccine. The strain changes year to year, resulting in a new vaccine annually.

Currently, there are four types of flu shots available to us. There is the traditional flu shot, injected into the muscle, which contains flu-virus particles that stimulate anti-flu immunity.

Next, there is the high dose flu shot, given to those 65 years or older as well as the intradermal flu shot that is accessible for people 18-64 years where a smaller needle is utilized.

Finally, doctors can employ a nasal-spray flu vaccine, containing a live, attenuated flu virus.

Recently, John Wherry, an associate professor of microbiology, found an approach that could result in a universal shot against the flu.

Wherry, the director of the Institute for Immunology at the University of Pennsylvania’s School of Medicine, reported that influenza virus-specific CD8+ T cells or any virus-specific non-neutralizing antibodies are comparatively ineffective when used alone. However, when put together, the virus-specific CD8+ T cells and the non-neutralizing antibodies foster strong, protective flu immunity.

To get these results, Wherry and his colleagues first primed mice with recombinant viruses or a non-influenza determinant and analyzed them 30 days later. However, with these modification, the researchers observed a lack of protection in the mice because of weight loss, high viral load and reduced lung function.

Wherry and his team next experimented by testing the non-neutralizing antibodies and virus-specific CD8+ T cells together. They induced an influenza virus-specific T cell response in the mice and after 30 days injected them with the H1N1 swine influenza virus strain.

These mice showed protection against viral challenges and stood up against the weight loss, decreased lung function, and high viral load issues present in the first experiment. This finding strongly suggests that the protection occurred based on the cooperation of the two substances — non-neutralizing antibodies and virus-specific T cells.

Specifically, this is known as a two-pronged approach. Wherry suggested that by utilizing two suboptimal vaccine approaches, he and his team have acquired a better effect than what each alone could produce in an experimental model.

With further research, past approaches to flu vaccine strains may be rethought and scientists can find more ways to combine T-cell and antibody vaccines to make the most successful union.

Ultimately, this study proved the potential success an influenza vaccine that elicits both CD8+T cells and antibodies would have in supplying protection to humans.

The new approach is considered a potential basis for an innovative influenza vaccine, or “universal vaccine” that could provide long-lasting protection.