Flu season is rapidly approaching, necessitating protection against influenza. Many important changes and updates have occurred for the 2019-2020 influenza season as brought forth by the Centers for Disease Control and Prevention (CDC).   This year, all standard flu vaccines and all recombinant vaccines are quadrivalent rather than trivalent, meaning they offer protection against four strains of the flu, rather than three. The vaccines were also grown in cells, as opposed to eggs.

For the 2019-2020 season, the CDC recommends that individuals under the age of 65 receive standard dose flu shots. High dose flu shots are available for those over the age of 65.  The CDC provides a list of all available vaccines approved during the 2019-2020 season.  The CDC recommends that individuals receive vaccinations before the end of October, but cautions against being vaccinated too early. Individuals that receive vaccinations as early as July or August may experience reduced protection near the end of the season.  Children under 8 are the exception, as they require two doses.  The CDC recommends that children under 8 undergo vacation as soon as possible, as they require 2 vaccinations, 4 weeks apart.

It is not possible to predict in advance the efficacy of the flu vaccine, but it typically reduces the risk of contracting the flu by 40-60%.  For individuals that do contract the flu after being vaccinated, the illness is typically less severe.  Individuals at highest risk of severe illness from influenza include children under 2 years of age, those over 65 years of age, pregnant women, immunosuppressed individuals, and those with chronic lung disease.  Diagnosis and treatment are outside of the scope of this post, but antivirals work best when administered within 48 hours of symptom onset.  For this reason, prompt symptom recognition and receipt of medical care is paramount. Baloxavir marboxil, a new single dose antiviral, was released in October 2018, and has shown significantly reduce influenza RNA viral.  More data is needed to definitively determine how this drug compares with oseltamivir.

Read more:

Centers for Disease Control and Prevention:  Frequently Asked Influenza (Flu) Questions: 2019-2020 Season

Harrison's Online Updates: Baloxavir Marboxil: A New, Single-Oral-Dose Antiviral Shows Rapid Clinical Benefit for Adults and Adolescents with Uncomplicated Influenza