Case Studies: Influenza

Pharmacy TimesSeptember 2023
Volume 89
Issue 9

Experts answer questions on influenza vaccines.

CASE 1: Vaccination Time


BZ is a 19-year-old man presenting to the pharmacy in mid-July. He explains that he will be starting his first semester of college this fall and asks for information on influenza vaccines and the best time to obtain an annual influenza vaccine during the semester. He has never received a flu shot because he has always been healthy. Although his college recommends he receive the influenza vaccine, he is hesitant because he has never had the flu. What counseling points should the pharmacist provide BZ about the influenza vaccine and optimal timing?

Doctor hand in blue gloves holding influenza vaccine for prevention human - Image credit: Arcyto |

Image credit: Arcyto |


Regardless of health status, patients 6 months or older should receive an annual influenza vaccine. BZ should be educated about the close quarters college students experience, particularly in the classrooms and dormitories. Close quarters usually create more opportunities for respiratory illnesses such as influenza to spread. Although he has never had the flu, he should consider receiving the influenza vaccination to keep him healthy and potentially prevent missed school days, hospitalization, or death. BZ should be counseled that the best time to obtain his annual influenza vaccine would be at the start of the fall semester in September or October to provide appropriate coverage through peak influenza season in December, January, or February. Vaccination in July or August is not recommended by the CDC for most adults, although it can be considered in children who require 2 doses or pregnant patients who are in their third trimester. Patients who have not received their influenza vaccination after October can still receive their annual vaccine within the recommended time frame.1

CASE 2: Infants and Influenza


TM comes into the pharmacy with her daughter and requests information about annual influenza vaccination in infants. She states that her daughter is 5 months of age and has never previously received an influenza vaccine. TM would like to know at what age she can schedule an appointment for her daughter to get a dose of the influenza vaccine. She is also concerned because her pediatrician said the baby would need 2 doses. TM states she only gets 1 dose, so she is confused why her baby needs 2 doses. What education should the pharmacist provide regarding populations eligible for annual influenza vaccines?


The pharmacist should educate TM that her daughter can receive the influenza vaccine at 6 months of age. According to the CDC, all patients 6 months or older should get an annual influenza vaccine. Two doses of the annual vaccine separated by 4 weeks are recommended for infants and children between the ages of 6 months and 8 years. Because TM’s baby is receiving her influenza vaccine for the first time, it is recommended she get the first dose as soon as the vaccine is available.2,3 It is important to educate TM that the first dose primes the immune system and the second dose provides long-term influenza protection. One study showed that children who had received 2 doses had a higher flu vaccine effectiveness than those who had not.4

CASE 3: Older Patients and Influenza


PG is a 65-year-old woman with a medical history of hypertension, diabetes mellitus, and a kidney transplant 5 years ago for which she is on immunosuppressive therapy. She presents to the pharmacy hoping to learn more about thevarious influenza vaccines on the market and receive her annual vaccination today. Which influenza vaccine should the pharmacist recommend PG receive based on her age and comorbidities?


There are 3 vaccines on the market that are preferentially recommended by the CDC for patients 65 years or older. PG can receive the Fluzone High-Dose Quadrivalent, Flublok Quadrivalent, or an adjuvant influenza vaccine such as Fluad Quadrivalent.5 If none of these are available, PG can receive standard-dose, unadjuvanted influenza vaccines. Compared with standarddose flu vaccines, the high-dose vaccine contains 3 to 4 times more antigens whereas the adjuvant vaccine contains an additive known as MF59 to provoke a stronger immune response.6 The CDC recommends utilization of high-dose or adjuvanted vaccines for individuals in this age group to elicit a strong immune response given their high risk of serious illness related to influenza infection. Although PG is immunocompromised, none of the above vaccines are live vaccines, so they can be administered to PG. She should not receive the live attenuated influenza vaccine because it is contraindicated in immunocompromised patients.5-7

CASE 4: Adverse Reactions With Influenza Vaccinations

JR is a 59-year-old man who calls the pharmacy asking for recommendations to manage adverse effects of the influenza vaccine. JR explains that he received an influenza vaccine in his left arm yesterday and has developed chills and redness at the injection site. He is healthy with no medical conditions. His wife told him that the flu vaccine can give you influenza and advised him to go to the hospital. He is worried that the vaccine may have inadvertently given him influenza. What counseling points should the pharmacist provide JR surrounding flu vaccine adverse effects and how to manage them?


JR should be educated that the influenza vaccine cannot cause influenza infection and that the vaccine he received did not contain live virus. The symptoms JR is experiencing are expected, common adverse effects of intramuscular influenza vaccines. The adverse effects of influenza vaccines are generally mild, shortlived, and self-resolving. For management of vaccine adverse effects, JR can consider OTC antipyretics, such as acetaminophen or ibuprofen, as well as nonpharmacologic strategies, such as remaining hydrated and well rested. JR should be educated that additional common adverse effects include soreness at the injection site, muscle aches, mild fever, fatigue, and headache. JR should be counseled to seek medical attention if his symptoms do not resolve after several days or if more serious adverse effects occur.8

About the Authors

Deanna Fox, PharmD, is a postgraduate year 2 pharmacy resident at Atlantic Health System in Morristown, New Jersey.

Kylie Helfenbein, PharmD, is a PGY-1 pharmacy resident at Atlantic Health System in Morristown, New Jersey.

Rupal Patel Mansukhani PharmD, FAPHA, NCTTP, is a clinical associate professor of pharmacy practice and administration at Ernest Mario School of Pharmacy at Rutgers, The State University of New Jersey in Piscataway, and a transitions-of-care clinical pharmacist at Morristown Medical Center in New Jersey.


  1. Centers for Disease Control and Prevention. Frequently asked influenza (flu) questions: 2022-2023 season. Reviewed November 21, 2022. Accessed July 6, 2023.
  2. Centers for Disease Control and Prevention. Flu vaccines are important for children. Reviewed November 30, 2022. Accessed July 6, 2023.
  3. Centers for Disease Control and Prevention. Child and adolescent immunization schedule by age. Reviewed April 17, 2023. Accessed April 5, 2023.
  4. Centers for Disease Control and Prevention. Study looks at flu vaccine dosing in children. Reviewed December 11, 2015. Accessed July 6, 2023.
  5. Centers for Disease Control and Prevention. Flu & people 65 years and older. Reviewed August 25, 2022. Accessed April 5, 2023.
  6. Centers for Disease Control and Prevention. Adult immunization schedule by age. Reviewed April 27, 2023. Accessed April 5, 2023.
  7. Centers for Disease Control and Prevention. ACIP flu meeting update: flu vaccines worked better than reported & ACIP recommends specific vaccines for seniors. Reviewed June 23, 2022. Accessed April 5, 2023.
  8. Centers for Disease Control and Prevention. Flu vaccine safety information. Reviewed August 25, 2022. Accessed April 5, 2023.

Related Videos
Female Pharmacist Holding Tablet PC - Image credit: Tyler Olson |
African American male pharmacist using digital tablet during inventory in pharmacy - Image credit: sofiko14 |
Young woman using smart phone,Social media concept. - Image credit: Urupong |
selling mental health medication to man at pharmacy | Image Credit: Syda Productions -
Medicine tablets on counting tray with counting spatula at pharmacy | Image Credit: sutlafk -
Concept of health care, pharmaceutical business, drug prices, pharmacy, medicine and economics | Image Credit: Oleg -
Image credit: |
Medical team -- Image credit: Flamingo Images |
© 2024 MJH Life Sciences

All rights reserved.