Three Flu Vaccine Misconceptions Clinicians Can Address in Minutes

Annual influenza vaccination is recommended for everyone aged 6 months and older who doesn’t have a contraindication, but clinicians often encounter patients with safety concerns that stem from familiar misconceptions.¹

What follows is a look at 3 common flu vaccine misconceptions and evidence-based strategies clinicians can use to navigate these conversations

The Post-Vaccination Symptom Window

Fear of adverse effects and the belief that injectable influenza vaccines contain live virus are recognized reasons adults delay or decline vaccination.²

The facts

Injectable influenza vaccines cannot cause influenza illness, so it’s important to distinguish reactogenicity from infection. Inactivated vaccines contain killed virus, while recombinant vaccines contain only an influenza surface protein, with no virus present. Common reactions, such as injection-site soreness, fatigue, headache, low-grade fever, or myalgia, generally begin soon after vaccination and resolve within 1 to 2 days.^1,3 A review of 39 studies similarly found that reported reactions varied by age and sex, but were generally mild.⁴ Because vaccine-induced protection takes approximately two weeks to develop, true illness after vaccination may reflect exposure to circulating influenza during that window or an unrelated respiratory infection.¹

What clinicians can say

• “The flu shot can’t cause influenza because it doesn’t contain virus capable of producing flu illness. You may notice fatigue, a sore arm, or even a mild fever for a day or two. Those are expected reactions related to your body’s immune response to the vaccine, and they’re usually much milder than having the flu.”

What Older Adults Should Know About MF59

The word “adjuvant” can be unfamiliar to patients, who may interpret it to mean that a vaccine is stronger than standard, or riskier.

The facts

The adjuvant MF59 is a highly purified squalene oil-in-water emulsion added to certain influenza vaccine formulations to amplify the immune response; it does not contain additional influenza virus. Immune defenses change with age, which can reduce protective responses to vaccination and increase the risk of severe influenza complications.^5,6

The Centers for Disease Control (CDC) and the Advisory Committee on Immunization Practices (ACIP) preferentially recommend high-dose inactivated, recombinant, or adjuvanted inactivated influenza vaccine for adults aged 65 years and older. If none is available, clinicians should use another age-appropriate vaccine rather than defer vaccination.⁶

A 2026 systematic review synthesized 10 randomized trials and 3 nonrandomized studies in adults aged 60 years and older. It found no significant increase in Guillain-Barré syndrome compared with nonadjuvanted vaccines or encephalitis compared with high-dose vaccine. Myalgia increased modestly (RR 1.35; 95% CI, 1.02 to 1.78) and injection-site pain occurred more often than with standard-dose nonadjuvanted vaccine (RR 1.58; 95% CI, 1.25 to 2.01). Events were predominantly mild and transient. The review combined formulations, comparators, and influenza seasons. Risk of bias varied, and rare adverse events could not be definitively excluded.⁷

What clinicians can say

• “As we age, our immune systems may not produce as robust a response as they once did. The adjuvant helps your immune system build a stronger response to the vaccine, but it doesn’t add more flu virus. You may experience temporary soreness, muscle aches, or fatigue, but studies didn’t see a higher risk of serious complications.”

Protecting Both the Pregnant Patient and the Newborn

Concern about fetal exposure during pregnancy can carry particular emotional weight.

The facts

Influenza during pregnancy is more likely to result in hospitalization and presents both maternal and fetal risk. The CDC recommends an injectable influenza vaccine during any trimester and advises against the live attenuated nasal spray during pregnancy. In addition to the protection offered to the pregnant patient, vaccination also transfers antibodies that can help protect the infant during the first months of life, before the infant is old enough to be vaccinated themselves.⁸

A 2026 meta-analysis of 31 observational studies involving more than 1.2 million individuals found that first-trimester vaccination was not associated with total birth defects after adjustment (OR 1.03; 95% CI, 0.98 to 1.07) or major birth defects (OR 1.03; 95% CI, 0.98 to 1.09).⁹

A separate systematic review included 63 studies, with 29 seasonal vaccination studies prioritized for synthesis. Meta-analyses found no significant association between vaccination and preterm birth, spontaneous abortion, or small-for-gestational-age birth. Descriptive syntheses didn’t identify increased risks of stillbirth, congenital anomalies, or maternal nonobstetric serious adverse events.¹⁰

Careful framing is important when presenting the evidence, as much of the pregnancy literature is observational and studies differed in outcome definitions and methods to address confounding and temporal bias.¹⁰

So while the accumulated surveillance and observational evidence doesn’t establish zero risk, it hasn’t identified increased risk for the outcomes studied.

What clinicians can say

• “Pregnancy increases the risk of complications and hospitalization with influenza, so the injectable flu vaccine is recommended during any trimester. The evidence hasn’t shown an increased risk of miscarriage or major birth defects, and the antibodies you develop can also help protect your baby after birth.”

Putting it into Practice: A Framework for the Vaccine Conversation

Beyond addressing specific misconceptions, how clinicians structure the conversation around vaccination can also shape outcomes in measurable ways. A 2025 systematic review of 143 studies found that more than two-thirds of communication interventions increased vaccine acceptance. The 3 predominant approaches in the literature were provider training, patient education, and structured provider-patient communication strategies including presumptive vaccine introduction, acknowledgment-based frameworks, and motivational interviewing.¹¹

A small proof-of-concept study found that the practical components of a short motivational exchange (open questions, reflective listening, autonomy-supportive information, concise clarification) can fit within the time constraints of a real clinical visit.¹²

The framework below draws on those same elements, organized around what the evidence supports for brief clinical encounters.

1. Presume: Make vaccination the standard

• “You’re due for this season’s flu vaccine. Let’s take care of that today.”

Opening with presumptive language frames vaccination as the expected standard of preventive care. In contrast, a participatory opening —“Are you interested in getting a flu vaccine this year?” — unintentionally signals vaccination is optional or peripheral.¹³

The literature supporting presumptive language over participatory openings isn’t specific to influenza, but reflects a broadly supported principle of vaccine communication that spans several vaccines and clinical contexts.¹³ However, participatory language can still be useful after a patient has expressed hesitancy and the clinician needs to understand what’s shaping the decision.

2. Listen: Identify the concern

• “What concerns you the most?”

When a patient does hesitate, pivot from announcement to exploration by asking a single open question to surface the specific concern. A systematic review of vaccine hesitancy in adults found that counseling is most effective when it’s from a trusted source with responses tailored to the patient rather than broad, unfocused vaccine education.²

3. Acknowledge: Validate the worry, not the misinformation

• “I understand why feeling sick soon afterward would make you wonder whether the vaccine caused it.”

Safety concerns, distrust, and misconceptions about vaccine characteristics are among the most consistently identified drivers of adult hesitancy. An acknowledgment that names the logic behind a concern — without affirming the underlying misbelief — signals that the clinician is listening, preserves trust, and creates space for correction.^2,12

4. Clarify: Offer one focused correction

• “Would it be helpful if I explained why the flu shot can’t cause influenza?”

Ask permission, then give one correction supported by one or two relevant facts. Save additional details for patients who request it. One review specifically recommends explaining relevant vaccine characteristics— including whether the vaccine contains live virus—and tailoring communication to the concern and context.^2,12

5. Recommend: Close the loop

• “Based on your age and health history, I still recommend that you receive the flu vaccine today.”

Return to a direct recommendation. In pregnancy-specific influenza literature, a meta-analysis of 49 studies found approximately 12-fold higher odds of vaccination among patients who received a healthcare professional’s recommendation compared with those who didn’t, although this association doesn’t establish causation.¹⁴

6. Leave the door open

• “I understand that you’re not ready today. We can discuss it again at your next visit, and my recommendation will remain the same.”

An initial refusal doesn’t have to end the discussion. A study cited in a maternal vaccination review found that 20% of pregnant patients who ultimately received influenza vaccination had previously declined it, supporting a renewed offer at later visits.¹⁵

Influenza vaccine misconceptions may not be resolved in a single encounter, but clinicians who make the recommendation clear, understand what’s driving hesitation, and address that concern accurately are well positioned to move the conversation forward, one visit at a time.

References

1.          Centers for Disease Control and Prevention. Misconceptions about seasonal flu and flu vaccines. Updated September 6, 2024. Accessed July 22, 2026. https://www.cdc.gov/flu/prevention/misconceptions.html

2.          Kumar S, Shah Z, Garfield S. Causes of vaccine hesitancy in adults for the influenza and COVID-19 vaccines: a systematic literature review. Vaccines (Basel). 2022;10(9):1518. doi:10.3390/vaccines10091518

3.          Centers for Disease Control and Prevention. Influenza (flu) vaccine safety. Updated December 20, 2024. Accessed July 22, 2026. https://www.cdc.gov/vaccine-safety/vaccines/flu.html

4.          Kini A, Morgan R, Kuo H, et al. Differences and disparities in seasonal influenza vaccine, acceptance, adverse reactions, and coverage by age, sex, gender, and race. Vaccine. 2022;40(11):1643–1654. doi:10.1016/j.vaccine.2021.04.013

5.          Centers for Disease Control and Prevention. Adjuvanted flu vaccine. Updated January 6, 2026. Accessed July 22, 2026. https://www.cdc.gov/flu/vaccine-types/adjuvant.html

6.          Centers for Disease Control and Prevention. Flu and people 65 years and older. Updated September 5, 2024. Accessed July 22, 2026. https://www.cdc.gov/flu/highrisk/65over.htm

7.          Manzotti ME, Bengolea A, Vazquez H. Systematic review of safety of MF59-adjuvanted influenza vaccine in older adults. Vaccines (Basel). 2026;14(4):360. doi:10.3390/vaccines14040360

8.          Centers for Disease Control and Prevention. Flu vaccine safety and pregnancy. Updated September 17, 2024. Accessed July 22, 2026. https://www.cdc.gov/flu/vaccine-safety/vaccine-pregnant.html

9.          Wu Y, Liu C, Qian X, Zhou Y, Xiong Y. Maternal influenza vaccination during the first trimester of pregnancy and risk for birth defects: an updated systematic review and meta-analysis. BMC Pregnancy Childbirth. 2026;26(1):713. doi:10.1186/s12884-026-09238-3

10.        Wolfe DM, Fell D, Garritty C, et al. Safety of influenza vaccination during pregnancy: a systematic review. BMJ Open. 2023;13(9):e066182. doi:10.1136/bmjopen-2022-066182

11.        Chen AMH, Draime JA, Engert M, et al. Utilization of provider-patient communication tools and approaches to facilitate vaccine confidence: a systematic review. Vaccines (Basel). 2025;13(11):1121. doi:10.3390/vaccines13111121

12.        Labbe S, Colmegna I, Valerio V, et al. Training physicians in motivational communication to address influenza vaccine hesitation: a proof-of-concept study. Vaccines (Basel). 2022;10(2):143. doi:10.3390/vaccines10020143

13.        Jacobson RM, St Sauver JL, Griffin JM, MacLaughlin KL, Finney Rutten LJ. How health care providers should address vaccine hesitancy in the clinical setting: evidence for presumptive language in making a strong recommendation. Hum Vaccin Immunother. 2020;16(9):2131–2135. doi:10.1080/21645515.2020.1735226

14.        Regan AK, Fiddian-Green A. Protecting pregnant people & infants against influenza: a landscape review of influenza vaccine hesitancy during pregnancy and strategies for vaccine promotion. Hum Vaccin Immunother. 2022;18(7):2156229. doi:10.1080/21645515.2022.2156229

15.        Rand CM, Olson-Chen C. Maternal vaccination and vaccine hesitancy. Pediatr Clin North Am. 2023;70(2):259–269. doi:10.1016/j.pcl.2022.11.004