A new study, published in the journal Nature Medicine, discusses a discovery that could lead to the development of a universal influenza vaccine.  The researchers used the 2009 H1N1 pandemic as a natural experiment to determine if existing cellular immunity could limit the symptoms seen in individuals without influenza antibodies.  Specifically, the study looked at the role of T cells in natural protection against the flu.  The researchers found that a certain type of T cells showed protection across different viruses, serving as a potential blueprint for a universal influenza vaccine.

According to the Centers for Disease Control and Prevention (CDC), the common flu vaccine is an annual vaccine to cover the flu season.  The seasonal flu vaccine protects against the strains that research indicates will be the most common during the upcoming season.  There are also traditional flu vaccines, which are non-seasonal flu vaccines that protect against H1N1, H3N2, and influenza B.  Flu vaccines come in a number of forms, including standard and high doses, as well as one that uses a smaller needle and a nasal spray for those that do not want an injection at all.

An analysis of the study in BBC News explains that influenza is able to change the proteins that protrude from the surface of the virus.  The material on the inside is common to many strains of flu. Vaccine researchers believe targeting the core of the virus may be the way to develop a universal vaccine.  T cells are thought to be able to recognize the proteins at the core and this study tested that theory.  This study found that, the higher the level of T cells, the milder the flu symptoms they presented.

Medline Plus explains that T cells are a type of white blood cells called lymphocytes. They make up part of the immune system. T cells help the body fight diseases or harmful substances.  Blood tests that separate white blood cells from red blood cells can assess the current T cell count in the body.

A CDC study examined the effectiveness of the seasonal influenza vaccine and found that, even with the vaccine, many still got the flu.  Thirty-two percent of the studied patients that presented with influenza had been given the flu vaccine.  Overall, there was still vaccine effectiveness across all age groups.  Those who got the seasonal flu vaccine were significantly less likely to develop the flu or an acute respiratory illness.