It's Time for Seasonal Flu Vaccination

Just as Winter inevitably came to Westeros, seasonal flu is coming to the US.

While we wait for a COVID-19 vaccine, it is in your best interest and that of the public health system to get your seasonal flu vaccination. The CDC has issued its 2020-21 guidelines. Here is a quick summary.

Who

• All children aged six months to 6 years of age. Additionally, children or adolescents who are receiving aspirin- or salicylate-containing medications and who might be at risk for experiencing Reye syndrome [1] after an influenza virus infection
• All persons aged ≥50 years
• Adults and children who have chronic pulmonary (including asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus) – Live attenuated influenza vaccine is relatively contraindicated in these individuals who should seek guidance from their physician. 
• Persons who are immunocompromised due to any cause
• Women who are or will be pregnant during the influenza season
• Children and adolescents (aged six months through 18 years) who are;
• Residents of nursing homes and other long-term care facilities;
• American Indians/Alaska Natives
• Persons who are extremely obese (body mass index ≥40 for adults)
• Care-givers “persons who live with or care for those who are at increased risk.”

In short, everyone except those with a “precaution,” such as experiencing Guillain-Barré syndrome [2] after receiving a flu vaccination, or concurrently experiencing a moderate or acute illness, or individuals over age 5 with asthma. And those with a contraindication, such as experiencing a severe allergic reaction to any component of the vaccine or the vaccination itself. 

When

Influenza season begins in October, so the recommendation is for individuals to get vaccinated now so that their immune system has the 3-4 weeks necessary to prime itself. While you can get vaccinated later in the season, why wait? Especially this year, when the symptoms of COVID-19 and seasonal flu overlap enough to make the diagnosis ambiguous without cultures. Do you want to be more anxious?

Which vaccine?

The primary vaccine is inactivated influenza virus – the virus is dead, and the vaccine is used to expose your immune system to the viral structure. The majority of these vaccines will be quadrivalent this year, protecting against two influenza A and two influenza B strains. It is recommended that adults over age 65 get the high-dose form as their immune systems may not respond as well to the lower dosages. These vaccines are made from eggs or cell culture as a medium for the growth of the virus.

There is also a recombinant vaccine made using genetic sequences of the influenza virus, using an insect cell line as a medium. It is made without egg media or the influenza virus itself. Finally, there is a live attenuated vaccine that is administered as a nasal spray. 

For most of us, any of the inactivated influenza vaccines will work, and the CDC indicates that you shouldn’t shop for a particular brand. The bottom line is that if you have no medical precautions or contraindications, vaccines are available at little or no cost at the neighborhood pharmacy. If you are not sure, see your physician or speak with your child’s pediatrician.

While the media is beginning to feature a foreboding discussion of the Twindemic or some other conjoining of seasonal flu and COVID-19 there may be a bit of a silver lining. With the need for masks and social distancing in place, we may see a decrease in seasonal flu cases; after all, these two diseases share their means of spread. In the meantime, the only wrong move is not to get vaccinated because you didn’t take the time to find out. 

[1] Reyes syndrome is a relatively rare disorder in children after a viral illness that is felt to be triggered by aspirin or salicylate use.

[2] Guillain-Barré syndrome is another rare disorder of the immune system that attacks the nervous system causing an ascending paralysis that might require mechanical intervention. It most often reverses itself over time.