It is flu season again and time to immunize. Unfortunately the flu vaccine is not like other vaccines, such as the MMR or dTAP, because a new vaccine has to be developed on an annual basis because the virus constantly mutates. According to the Center for Disease Control and Prevention (CDC), quadrivalent and trivalent influenza vaccines will be available for the 2017-2018 season. Inactive influenza vaccines (IIVs) will be available in trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will also be available in trivalent (RIV3) and quadivalent (RIV4) formulations. Live attenuated vaccine (LAIV4), also known as FluMist®, is not recommended this year due to concerns of effectiveness; however, there are no recommended preferences between the different injectable products. This season the vaccine viruses include an A/Michigan/45/2015 (H1N1)pdm09-like virus, an A/HongKong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Additionally the quadrivalent influenza vaccines contain aa B/Phuket/3073/2013-like virus.[i] Despite popular belief in the general population, no one can get the flu from an inactivated influenza vaccine. The vaccine only covers the respiratory-type of influenza, not the “stomach flu”.
The CDC estimates that 5 to 20 percent of Americans come down with the flu annually.[ii] It was responsible for 4,605 deaths or a rate of 1.4 deaths per 100,000 persons in 2014. It is highly contagious and can be a serious illness in vulnerable patients, such as the elderly, children under 5 years, and patients who are immune-compromised or have chronic medical conditions. Immunization for influenza is so important to minimize serious medical complications and prevent or reduce the death rate from influenza. Despite the benefits of these vaccinations, the rate of vaccination is not good:
- 9% of children, ages 6 months to 17 years
- 8% of adults 18-49 years
- 2% of adults 50-64 years
- 2% of adults 65 years and older
The symptoms of the common cold are gradual and mild, but the flu symptoms usually hit the patient hard and fast. Flu symptoms may include the following:
- Body aches
- Extreme fatigue
- Sore throat
- Mild congestion
- Vomiting and diarrhea (not common in adults, but occurs more frequently in children)
The flu is a virus, and there are antiviral medications now available to help shorten the duration of the illness or protect a person who has been exposed, if taken within 48 hours of symptoms or exposure. Unfortunately, if the flu season is heavy, these medications often fall in short supply from the high demand. If the oral suspension of Tamiflu® is in short supply it can be compounded from the commercial tablets. Pharmacists, however, need to be aware that the compounded formula in the Roche Pharmaceuticals labeling for Tamiflu® is a different strength than the commercial product (15 mg/mL instead of 12 mg/mL) and this can increase the risk of a dosing error with the drug, especially in health-systems and facilities that have standardized formularies and established protocols. There are other published formulas for compounded oseltamivir oral suspension at 12 mg/mL that are a better choice to reduce this risk.[iii], [iv]
The pharmacist is the first line of defense to prevent the flu due to easy access. Most pharmacies now provide immunization services. This is an opportunity to educate the general public and dispel the myths associated with the vaccines. Hopefully, more people will decide to receive the flu vaccine, reducing illness, complications or even death among vulnerable groups such as the elderly and infants.
[i] Centers for Disease Control and Prevention. Prevention and Control of Seasonal Influenza with Vaccines. http://wwwcdc.gov/flu/professionals/acip/index.htm. Accessed 09/11/2017.
[iii] Ford SM, Kloessel LG, Grabenstein JD. Stability of Oseltamivir in Various Extemporaneous Liquid Preparations. Inter J Pharm Compound 2007; 11(2):164
[iv] Allen LV Jr. Osetamivir 12 mg/mL Oral Suspension. Inter J Pharm Compound 2007;11(4):332