What if there was a major scientific breakthrough that could dramatically decrease an individual’s chances for severe and life-threatening illness complications? Furthermore, what if this breakthrough would protect those with weaker immunity from lethal infection including young children and the elderly? What if the scientists who developed the technology made it available at low cost or even no cost? Such a boon to society would be difficult to differentiate from magic. Even more impressive is that this is not some far-fetched imaginary technology. It is the flu shot, available now at pharmacies and clinics everywhere.

What’s the Catch?

No catch. In fact, that may be the problem. The flu shot works so well most years that people think “why get the flu shot, it was no big deal last season”. Or alternatively, a patient gets sick with an unrelated virus and thinks “why get the flu shot if I get sick anyway?” Or, even more commonly, erroneously supposes the flu shot caused an illness and thinks “I always get sick when I get the flu shot”.

Anyone can have an opinion regardless of medical training. With the proliferation of social media and the internet, those opinions can be shared and published without regard for factual basis, or peer-reviewed impartial research and development. The impact of these statements can be even more profound when the person offering the opinion is a celebrity or otherwise well-respected community or society figure.

The Flu Shot and Herd Immunity

Unfortunately, vaccines rely in part on what is called “herd immunity”. This means that the more people in a population are vaccinated, the better it works. When people electively decide not to vaccinate, it places not just those individuals, but the whole population at risk. There is a resurgence in the Pacific Northwest in viruses largely extinct in recent memory. This includes the measles and whooping cough: viral diseases that can be prevented with routine vaccination. For most people, these viruses result in a self-limiting infection. However, for patients with existing respiratory dysfunction or underlying lung disease, they can prove life-threatening.

Vaccine “Drifts” and “Shifts”

Another wrinkle in the story is that viruses sometimes undergo something called “drift” or “shift”. This can be a small change in genetics, resulting in a less effective vaccine (drift). It can also result in a large rapid change in genetic structure, resulting in a more virulent disease (shift). Those who remember the Swine Flu in 2009 may recall how much more severe symptoms could be than traditional influenza. In this case, the vaccine may be less effective but may serve to decrease the scope or severity of disease.

Who Should Get Their Flu Shot?

For adults with egg allergy other than hives: Administer IIV or RIV (influenza vaccine) in a medical setting under supervision of a health care provider who can recognize and manage allergic conditions.” (Center for Disease Control, Adult Immunization Schedule for 2018). The Flu Shot is recommended for everyone else, including expecting mothers.

Damon Armitage, MD
Medical Director, Camas Swale Medical Clinic