Flu vaccine helps others

Do you know that when you get the flu vaccine, you’re helping protect those around you from illness too? This is especially important for those who are not healthy or have comprised immune systems. We asked Dr. Jon McCullers, flu researcher and pediatrician in chief at Le Bonheur Children's Hospital, to explain how the concept called herd immunity works.

The influenza vaccine works bests in healthy children and adults. It is not as effective in:

  • those with compromised immune systems, such as young children and the elderly
  • persons of any age with immune systems that are weakened by chronic illness or immunosuppressive drugs such as steroids

The best way to protect these individuals is to vaccinate them and close contacts around them. This allows those individuals to have personal immunity, but also helps them avoid being exposed to the flu altogether.

Herd immunity is an extension of this idea – in order for a virus to freely transmit from person to person and spread throughout a community, it needs to find susceptible hosts to infect. The more persons who are vaccinated, the greater the chances that a virus or bacteria will reach a dead-end and not be able to pass itself on.

For example, the introduction of the pneumococcal vaccine two decades ago in U.S. children decreased pneumococcal infections in those kids who were vaccinated, but also in adults who were not vaccinated. Adults were not infected simply because they weren’t exposed, not because they were immune.

A similar phenomenon is seen with influenza – if we vaccinate a high percentage of school children, the elderly don’t get exposed as often and are less likely to get sick and die from the flu.

Right now only about 30 percent of persons in Memphis get the vaccine – not high enough to see herd immunity.

Jon McCullers, MD

Dr. Jon McCullers is chair of the Department of Pediatrics for the University of Tennessee Health Science Center and pediatrician in chief for Le Bonheur Children’s Hospital. Before joining Le Bonheur, McCullers worked as a pediatric infectious disease researcher at St. Jude Children’s Research Hospital, studying influenza and co-infections.

Watch and share this video of Le Bonheur parent Joanne Cunningham explain why the flu vaccination is important to her son Jacob.

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