My Patient Info Sheet for the Flu Vaccine for Informed Consent.

For the Pro side, please visit the https://www.cdc.gov/flu/ It is important to review both sets of data to make an informed decision.

• MY PATIENT INFO SHEET FOR THE FLU VACCINE FOR INFORMED CONSENT

  
  

  For the Pro side, please review the CDC's data at https://www.cdc.gov/flu/. The references below are intentionally curated to offer an alternative to that narrative — please review both sources before making a decision.

  
  

  1. Jefferson T, Di Pietrantonj C, Rivetti A, Bawazeer GA, Al Ansary LA, et al. Influenza vaccines for preventing influenza in healthy adults. Cochrane Collaboration.

  - Collaboration report included 40 clinical trial studies of more than 70,000 people. In a perfectly matched year, it showed up to 80% benefit.

  - But since strains don't often match perfectly, effectiveness ranged from 50% down to as low as 30%. So just as many people theoretically benefited as didn't on an average year.

  - It showed modest days lost from work with the vaccine, and NO evidence was found to decrease hospitalization or complication rates.

  - Another analysis put it this way: when the vaccine matched the flu strain, 4 percent who weren't vaccinated got the flu, versus 1 percent of vaccinated people — a difference of 3 percent. When the vaccine didn't match the strain, 2 percent of unvaccinated people got the flu versus 1 percent of vaccinated — a difference of 1 percent.

  - The Cochrane Collaboration's 2010, 2014, and 2018 meta-analyses of published influenza vaccine studies found the influenza vaccination has no effect on hospitalization, and no evidence flu vaccines prevent viral transmission or complications. The Cochrane researchers concluded the scientific evidence seems to discourage the utilization of vaccination against influenza in healthy adults as a routine public health measure (Cochrane Library, CD001269.pub4, page 22).

  
  

  2. Kelley NS, Manske JM, Ballering KS, Leighton TR, Moore KA. The Compelling Need for Game-Changing Influenza Vaccines: An analysis of the influenza vaccine enterprise and recommendations for the future. Center for Infectious Disease Research & Policy, October 2012.

  - Removing more of the "flawed" studies, this analysis found 59% effectiveness in a perfectly matched year for ages 18-64.

  - No benefit was seen in the elderly (over 65) or under 18 in other studies.

  - The paper suggests the flu vaccine is not ideal, but due to lack of financial incentive, more beneficial vaccines are not likely to be found.

  
  

  3. Cowling BJ, Fang VJ, Nishiura H, et al. Increased Risk of Noninfluenza Respiratory Virus Infections Associated With Receipt of Inactivated Influenza Vaccine. Clin Infect Dis. 2012;54(12):1778-1783.

  - TIV (trivalent inactivated influenza vaccine) recipients had a higher risk of confirmed non-influenza respiratory virus infection (RR, 3.46; 95% CI, 1.19-10.1).

  - The majority of non-influenza respiratory virus detections were rhinoviruses and coxsackie/echoviruses, and the increased risk among TIV recipients was also statistically significant for these viruses.

  
  

  4. Mina MJ, McCullers JA, Klugman KP. Live attenuated influenza vaccine enhances colonization of Streptococcus pneumoniae and Staphylococcus aureus in mice. mBio. 2014;5(1). doi:10.1128/mBio.01040-13

  - The potent and often lethal effects of an antecedent influenza virus infection on secondary bacterial disease have been reported.

  - Viral replication induced epithelial and mucosal degradation, and the ensuing innate immune response yielded diminished capacity to avert secondary bacterial infections.

  - Recent clinical and experimental data suggest that influenza virus infection may exert its influence beginning in the upper respiratory tract by enhancing susceptibility to bacterial colonization.

  
  

  6. Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V. Vaccines for preventing influenza in healthy children. Cochrane Database Syst Rev. 2012;(8):CD004879.

  - 75 worldwide studies, including 17 randomized trials — in children older than 2, the inactivated influenza vaccine is about 36% effective.

  - Under age 2, effectiveness was equal to placebo; no evidence of reduced mortality, hospital admissions, serious complications, or community transmission.

  
  

  7. Jefferson T, Smith S, Demicheli V, et al. Assessment of the efficacy and effectiveness of influenza vaccines in healthy children: systematic review. Lancet. 2005;365(9461):773-780.

  - No evidence of reduced mortality, admissions, complications, or decreased community transmission of influenza.

  
  

  8. Joshi AY, Iyer VN, Hartz MF, Patel AM, Li JT. Effectiveness of trivalent inactivated influenza vaccine in influenza-related hospitalization in children: a case-control study. Allergy Asthma Proc. 2012;33(2):e23-27.

  - Study of children 6 months to 18 years, 1999-2007.

  - Children vaccinated against influenza were three times more likely to be hospitalized for influenza-related complications than unvaccinated children (OR=3.67).

  - Asthmatic children who received the influenza vaccine were also more likely to be hospitalized than those who did not. Severity of asthma did not affect the outcome.

  
  

  9. Seasonal Influenza and Vaccine Herd Effect. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4083064

  - Observational study, 1968-2001, showed no decreased mortality rate with increasing vaccination coverage from 15% to 65%.

  
  

  10. Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutions. Cochrane Database Syst Rev. 2013;(7):CD005187.

  - No evidence to support that vaccinating healthcare workers in long-term care facilities affected laboratory-proven influenza or complications (pneumonia, hospitalization, or death due to pneumonia) in residents over age 60.

  
  

  11. Doshi P. Influenza: marketing vaccine by marketing disease. BMJ. 2013;346:f3037. doi:10.1136/bmj.f3037

  
  

  12. Doshi P. Are US flu death figures more PR than science? BMJ. 2005;331(7529):1412. doi:10.1136/bmj.331.7529.1412

  - Documents that public health authorities' aggressive promotion of the influenza vaccine is not supported by the medical literature and fails to acknowledge serious vaccine risks — e.g., contrary to widely cited claims, only 16% of tested respiratory specimens are positive for influenza, and serious vaccine adverse events are well documented internationally.

  
  

  13. Carrat F, Lavenu A, Cauchemez S, Deleger S. Repeated influenza vaccination of healthy children and adults: borrow now, pay later? Epidemiol Infect. 2006;134:63-70.

  - Shows that repeated influenza vaccination at a younger age substantially increases the risk of influenza at older age.

  
  

  14. Skowronski DM, De Serres G, Crowcroft NS, et al. Association between the 2008-09 seasonal influenza vaccine and pandemic H1N1 illness during Spring-Summer 2009: four observational studies from Canada. PLoS Med. 2010;7(4):e1000258.

  - Recipients of the influenza vaccine had significantly increased risk of the H1N1 virus compared to those who didn't receive it.

  - Recipients had increased need for medical attention due to the H1N1 virus.

  
  

  15. BMJ. 1998;316(7149). doi:10.1136/bmj.316.7149.3a. http://www.bmj.com/cgi/content/full/316/7137/S2-7137

  - "In adjusted models, we observed 6.3 (95% CI 1.9-21.5) times more aerosol shedding among cases with vaccination in the current and previous season compared with having no vaccination in those two seasons."

  
  

  16. Study: Prior-year vaccination cut flu vaccine effects, 2014-15. CIDRAP. https://www.cidrap.umn.edu/news-perspective/2016/04/study-prior-year-vaccination-cut-flu-vaccine-effects-2014-15

  - Prior-year vaccination cut the current year's efficacy of the flu vaccine.

  
  

  17. Study: getting flu shot 2 years in a row may lower protection. CIDRAP, 2013. https://www.cidrap.umn.edu/news-perspective/2013/03/study-getting-flu-shot-2-years-row-may-lower-protection

  - "The vaccine was found to be 62% effective in those who hadn't been vaccinated the previous year... In contrast, those who had been vaccinated 2 years in a row got no significant protection."

  
  

  18. Children Who Get Flu Vaccine Have Three Times Risk Of Hospitalization For Flu, study suggests. American Thoracic Society, May 2009. https://www.sciencedaily.com/releases/2009/05/090519172045.htm

  - The inactivated flu vaccine does not appear to be effective in preventing influenza-related hospitalizations in children, especially those with asthma. Children who get the flu vaccine are more at risk for hospitalization than peers who do not, according to this research. The findings raise questions about vaccine efficacy but do not implicate the vaccine as a direct cause of hospitalization, according to researchers.

  
  

  19. Vaccine-Induced Anti-HA2 Antibodies Promote Virus Fusion and Enhance Influenza Virus Respiratory Disease. Sci Transl Med. 2013;5(200):200ra114. doi:10.1126/scitranslmed.3006366

  - Pigs vaccinated against one strain of influenza were worse off if subsequently infected by a related strain.

  
  

  20. Joshi AY, Iyer VN, Hartz MF, Patel AM, Li JT. Effectiveness of trivalent inactivated influenza vaccine in influenza-related hospitalization in children: a case-control study.

  - TIV did not provide any protection against hospitalization in pediatric subjects, especially children with asthma. A threefold increased risk of hospitalization was found in subjects who did receive the TIV vaccine.

  
  

  21. Influenza vaccines seem to be modifying influenza into a dangerous dengue-like disease. www.bmj.com/content/360/bmj.k1378/rr-15

  
  

  22. Death rates due to actual positive flu tests average under 1,000 per year in over 300,000,000 people, per CDC National Vital Statistics Reports.

  - The 30,000-50,000 death figures commonly reported in media are due to flu AND pneumonia combined (all-cause pneumonia, including from HIV, COPD, elderly patients, cancer, etc.).

  - Pediatric flu deaths are reportable and range from 60-120 annually. Adult flu deaths are not individually reportable but are obtained via death certificates, which allows estimation to range widely.

  
  

  23. Adverse reaction reporting is flawed due to reporter bias.

  - Standard medical training teaches that any significant flu-like illness following vaccination is likely coincidence or would have been worse without the vaccine.

  - Physicians are not trained to recognize serum sickness and are often too busy to report. (Reference: Miller's Review of Critical Vaccine Studies.)

  
  

  24. Nanri A, Nakamoto K, Sakamoto N, Imai T, Akter S, Nonaka D, Mizoue T. Association of serum 25-hydroxyvitamin D with influenza in a case-control study nested in a cohort of Japanese employees. Clin Nutr. 2017;36(5):1288-1293. doi:10.1016/j.clnu.2016.08.016

  - Lower influenza risk associated with vitamin D sufficiency among unvaccinated participants warrants further investigation.

  
  

  25. Roos R. Study: prior-year vaccination cut flu vaccine effects in 2014-15. CIDRAP News.

  
  

  26. Smith DJ, Forrest S, Ackley DH, Perelson AS. Variable efficacy of repeated annual influenza vaccination. Proc Natl Acad Sci U S A. 1999;96:14001-14006.

  
  

  27. Skowronski DM, De Serres G, et al. Role of egg-adaptation mutations in low influenza A(H3N2) vaccine effectiveness during the 2012-2013 season. Clin Infect Dis. 2018. doi:10.1093/cid/ciy350

  - Using a case-control design and data from Canada's Sentinel Practitioner Surveillance Network for 2014-2015, participants who received the 2014-2015 vaccine without vaccination the year before had significant protection against influenza A(H3N2), but those who had received the identical 2013-2014 vaccine the previous year had no increased protection. Those vaccinated three years in a row had an increased risk of contracting influenza compared with unvaccinated participants.

  
  

  28. Systemic autoimmunity appears to be a consequence of over-stimulating the host's immune system through repeated immunization. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0008382

  
  

  29. The Autoimmune/Inflammatory Syndrome Induced by Adjuvants (ASIA). https://www.ncbi.nlm.nih.gov/pubmed/28741088

  
  

  30. Subgroup analysis demonstrates that immunosuppressive therapies and non-adjuvanted vaccines lead to less immunogenicity in humoral response in flu-vaccinated SLE (lupus) patients.

  
  

  31. Bodewes R, Fraaij PLA, Geelhoed-Mieras MM, et al. Annual vaccination against influenza virus hampers development of virus-specific CD8+ T cell immunity in children. J Virol. 2011;85(22):11995-12000. doi:10.1128/JVI.05213-11

  - Results indicate that annual influenza vaccination is effective against seasonal influenza but hampers the development of virus-specific CD8+ T cell responses.

  
  

  32. Armstrong PK, Dowse GK, Effler PV, et al. Epidemiological study of severe febrile reactions in young children in Western Australia caused by a 2010 trivalent inactivated influenza vaccine. BMJ Open. 2011;1(1):e000016. doi:10.1136/bmjopen-2010-000016

  - "Children aged 4 years and under who had received TIV from one vaccine manufacturer (CSL Biotherapies) had a 200-fold higher rate of febrile convulsions than the only reliable published estimate..."

  
  

  33. "With universal vaccination, 97% of influenza cases will occur in vaccinated workers who will not be masked. Thus, masking unvaccinated workers is most likely punitive and coercive rather than a well-reasoned strategy for reducing transmission in the healthcare setting." https://academic.oup.com/ofid/article/6/4/ofy214/5427979

  
  

  34. The four cluster-randomized controlled trials underpinning policies of enforced healthcare worker influenza vaccination attribute implausibly large reductions in patient risk to HCW vaccination, casting doubt on their validity. The HCW-attributable risk and vaccine-preventable fraction remain unknown. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0163586

  
  

  35. Study explains why H1N1 flu can cause narcolepsy. https://sciencenordic.com/denmark-diseases-genetics/study-explains-why-h1n1-flu-can-cause-narcolepsy/1394775

  - If a person's immune system contains the cells identified as culprits behind narcolepsy and comes into contact with either H1N1 or the vaccine against H1N1, the immune response can activate and narcolepsy can develop.

  
  

  36. What, in Fact, Is the Evidence That Vaccinating Healthcare Workers Against Seasonal Influenza Protects Their Patients? A Critical Review. Int J Family Med. 2012;2012:205464. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3502850/

  - "The arguments for uniform healthcare worker influenza vaccination are not supported by existing literature. The decision whether to get vaccinated should, except possibly in extreme situations, be that of the individual healthcare worker, without legal, institutional, or peer coercion."

  
  

  37. Rikin S, et al. Assessment of temporally-related acute respiratory illness following influenza vaccination. Vaccine. 2018;36:1958-1964.

  - Among children, there was an increase in the hazard of acute respiratory illness caused by non-influenza respiratory pathogens post-influenza vaccination compared to unvaccinated children during the same period.

  
  

  38. Kelly H, Jacoby P, Dixon GA, et al. Vaccine effectiveness against laboratory-confirmed influenza in healthy young children: a case-control study. Pediatr Infect Dis J. 2011;30(2):107-111.

  - When the actual study data is examined, children with influenza vaccination showed a higher rate of non-influenza viral lung infections, by 55%.

  
  

  39. Dierig A, Heron LG, Lambert SB, et al. Epidemiology of respiratory viral infections in children enrolled in a study of influenza vaccine effectiveness. Influenza Other Respir Viruses. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181477/pdf/irv0008-0293.pdf

  - "We did, however, unexpectedly find that non-influenza ILI occurred about 1.6 times more commonly in children vaccinated with one or two doses of the influenza vaccine than in unvaccinated children."

  
  

  40. Christian LM. Inflammatory responses to trivalent influenza virus vaccine among pregnant women.

  - Trivalent influenza virus vaccination elicits a measurable inflammatory response among pregnant women. As adverse perinatal outcomes including preeclampsia and preterm birth have an inflammatory component, a tendency toward greater inflammatory responding to immune triggers may predict risk of adverse outcomes.

  
  

  41. Lanza GA, Barone L, Scalone G, et al. Inflammation-related effects of adjuvant influenza A vaccination on platelet activation and cardiac autonomic function. https://pubmed.ncbi.nlm.nih.gov/20964738/

  - Influenza A vaccine induced platelet activation and sympathovagal imbalance toward adrenergic predominance, together with an inflammatory reaction. The vaccine-related platelet activation and cardiac autonomic dysfunction may transiently increase the risk of cardiovascular events.

  
  

  42. Khurana S, et al. Vaccine-induced anti-HA2 antibodies promote virus fusion and enhance influenza virus respiratory disease. Sci Transl Med. 2013;5(200):200ra114.

  - Pigs vaccinated with whole inactivated H1N2 influenza virus had enhanced pneumonia and disease after infection with another strain, pH1N1. Immune sera from H1N2-vaccinated pigs contained high titers of cross-reactive hemagglutinin antibodies that enhanced pH1N1 infection in cell culture by promoting virus membrane fusion, correlating with lung pathology.

  
  

  43. Trotta F, et al. Evaluation of safety of A/H1N1 pandemic vaccination during pregnancy: cohort study. BMJ. 2014;348:g3361.

  - A limited increase in the prevalence of gestational diabetes (1.26, 1.04-1.53) and eclampsia (1.19, 1.04-1.39) was seen in vaccinated women. Both are related to inflammation and immune dysregulation, making a connection to immune stimulation from the flu vaccine plausible.

  
  

  45. Effectiveness of influenza vaccine during pregnancy in preventing hospitalizations and outpatient visits for respiratory illness in pregnant women and their infants. Am J Perinatol. 2004;21(6):333-339.

  - Nearly 50,000 pregnant women over five flu seasons found the rate of influenza-like illness in vaccinated women was identical to the rate in unvaccinated women, with no difference in outpatient visit risk. Hospital admissions were rare in both groups and no women died of respiratory illness during pregnancy. Infants born to vaccinated women had the same risk for influenza or pneumonia admissions as infants born to unvaccinated women.

  
  

  46. France EK, et al. Impact of maternal influenza vaccination during pregnancy on the incidence of acute respiratory illness visits among infants. December 2006.

  - Unable to demonstrate that maternal influenza vaccination reduces respiratory illness visit rates among infants.

  
  

  47. Original Antigenic Sin. http://vaccinepapers.org/influenza-vaccine-immune-suppression/

  - A poorly-matched influenza vaccine may cause illness (and increase risk of influenza illness) via original antigenic sin (OAS) — a well-established immunological phenomenon in which the immune system responds to a second infection as though it were the first, producing a defective and delayed response. By receiving an influenza vaccine poorly matched to circulating strains, the immune system may be improperly trained, which may be worse than no training at all.

  
  

  48. Weekly U.S. Influenza Surveillance Report, CDC, December 11, 2015. Only 1.2% of 102,675 respiratory specimens from Oct 4-Nov 28 tested positive for influenza viruses.

  
  

  49. Cumulative data (April 2, 2016) showed a range around the country from 15.1%-22%.

  - Of the $282 million the National Vaccine Injury Compensation Program (NVICP) paid out in FY2017 for vaccine injuries and death, roughly $188 million was for influenza vaccine injuries and deaths. Influenza vaccines make up about 42% of administered vaccines but 57% of compensated vaccine petitions (2006-2016). Source: NVICP Data & Statistics, HRSA.

  
  

  50. Skowronski DM, et al. Interim estimates of 2014/15 vaccine effectiveness against influenza A(H3N2) from Canada's Sentinel Physician Surveillance Network. Euro Surveill. 2015;20(4).

  - A 2015 study found influenza vaccines in Canada had a -8% effectiveness rate (negative eight percent) and recommended "adjunct protective measures... to minimize morbidity and mortality."

  
  

  51. Ng S, et al. Characteristics of vaccine failures in a randomized placebo-controlled trial of inactivated influenza vaccine in children. Pediatr Infect Dis J. 2014;33(2):e63-66.

  - TIV was not observed to ameliorate clinical symptoms or viral shedding among vaccine failures compared with infected placebo recipients.

  - Companion Cochrane review (Demicheli V, Jefferson T, Ferroni E, Rivetti A, Di Pietrantonj C, Feb 2018): 52 clinical trials of over 80,000 adults. Impact of bias could not be determined for about 70% of included studies due to insufficient reporting; around 15% were well-designed and conducted. Injected influenza vaccines probably have a small protective effect against influenza and influenza-like illness (moderate-certainty evidence): 71 people would need to be vaccinated to avoid one influenza case, and 29 to avoid one case of influenza-like illness. Vaccination may have little or no appreciable effect on hospitalizations (low-certainty evidence) or working days lost.

  
  

  52. Anderson ML, Dobkin C, Gorry D. The effect of influenza vaccination for the elderly on hospitalization and mortality: an observational study with a regression discontinuity design. Ann Intern Med. 2020;172(7):445-452. doi:10.7326/M19-3075

  - "No evidence indicated that vaccination reduced hospitalizations or mortality among elderly persons. The estimates were precise enough to rule out results from many previous studies."

  
  

  53. Phone conversation with a CDC Medical Officer, Epidemiology and Prevention Branch, Influenza Division, NCIRD. Agreed with the information compiled here and stated this is the best available data. Due to lack of evidence, the CDC does not officially endorse flu vaccine mandates. Also acknowledged that due to changing viral strains and imperfect vaccine matching, we will likely never have definitive studies.

  
  

  54. Flu vaccine efficacy ranges from 10-60%, but is usually on the lower end. https://www.cdc.gov/flu/vaccines-work/past-seasons-estimates.html

  - Informed consent requires a formal opting in, never a formal opting out, and must always be voluntary and free of institutional or government interference, coercion, cost, or penalty. The Nuremberg Code, the Helsinki Declaration, and the 2005 Declaration on Bioethics and Human Rights support the right to informed consent. Vaccine mandates raise questions about bodily autonomy and self-determination. Vaccination is an invasive medical procedure delivering complex biochemical compounds by injection, as documented in package inserts.

  
  

  55. Positive association between COVID-19 deaths and influenza vaccination rates in people 65+, with significant regional variation globally. Further exploration was called for. https://peerj.com/articles/10112/

  
  

  56. Vaccine-derived virus interference was significantly associated with coronavirus and human metapneumovirus. https://pubmed.ncbi.nlm.nih.gov/31607599/

  
  

  57. Although elderly influenza vaccination coverage increased from about 15% to about 65% during 1980-1999 in the US, estimates of influenza-related mortality also increased during this period; the increase in elderly vaccination coverage was not accompanied by a decline in influenza-related mortality. https://www.sciencedirect.com/science/article/abs/pii/S0531513104001694

  
  

  58. CDC seasonal vaccine effectiveness estimates, recent seasons: 2021-2022: approximately 36%. 2022-2023: approximately 30%. 2023-2024: approximately 44%. 2024-2025: approximately 46% against hospitalization, 32-54% against outpatient illness (preliminary CDC network data). These figures vary substantially by network, age group, and whether illness or hospitalization is being measured, and preliminary in-season figures are often revised.

  
  

  59. All-cause mortality claims: observational and meta-analytic data are often cited as showing a 20-30% relative reduction in all-cause mortality among vaccinated versus unvaccinated. In absolute terms, if baseline mortality is 0.1%, that is an absolute risk reduction of only 0.02-0.03 percentage points. These mortality studies carry a well-documented methodological limitation known as "healthy vaccinee bias" — people who are already sicker or frailer are less likely to get vaccinated in the first place, which can make the vaccine look more protective than it is.

  
  

  60. Recognized adverse effects of the flu vaccine, though rare, include anaphylaxis, Guillain-Barre syndrome, and febrile seizures in children.

  
  

  61. Shrestha NK, Burke PC, et al. Effectiveness of the Influenza Vaccine During the 2024-2025 Respiratory Viral Season. medRxiv preprint, 2025 (not yet peer-reviewed).

  - 53,402 Cleveland Clinic employees in Ohio. Vaccinated employees had a 27% higher hazard of lab-confirmed flu than unvaccinated employees (HR 1.27, 95% CI 1.07-1.51, P=0.007), a calculated vaccine effectiveness of -26.9% (95% CI -55.0 to -6.6%).

  - Acknowledged limitations: vaccinated employees may have been tested more often than unvaccinated employees, the vaccinated group was 4.5 times larger than the unvaccinated group, the study did not assess hospitalization or death, and it involved a single health system's workforce, mostly young and female.

  
  

  62. Reanalysis of FDA Clinical Data for mFLUSIVA (mRNA-1010): Unfavorable Risk-Benefit Profile Supports Market Withdrawal. Zenodo preprint, 2026 (not peer-reviewed).

  - mFLUSIVA (Moderna's mRNA-based flu vaccine) was FDA-approved in August 2026 for adults 50 and older. This reanalysis of the FDA advisory committee briefing document calculated that 137 vaccinations were needed to prevent one confirmed influenza-like illness, 1,003 to prevent one higher-level-care visit, and 5,017 to prevent one hospitalization, compared with a standard-dose vaccine.

  - Solicited adverse reactions were more frequent with mFLUSIVA than the standard-dose comparator. The authors flagged an imbalance in deaths of unspecified cause (23 vs. 9) as warranting further investigation, while noting the trial was not designed or powered to assess mortality as an endpoint.

  - For context: the published NEJM trial data describe mRNA-1010 as more effective than standard-dose vaccine at preventing confirmed illness, with adverse reactions described as mostly mild-to-moderate.

  
  

  63. Batalla-Rebolla N, et al. Association Between the Introduction of Pediatric Influenza Vaccination and Influenza Diagnoses in Primary Care and Hospitalizations: An Interrupted Time Series Study. Vaccines (Basel). 2026;14(5):372. doi:10.3390/vaccines14050372

  - Catalonia study of all influenza diagnoses in primary care and influenza-related hospitalizations, October 2018-August 2025, following the 2023-24 introduction of systematic vaccination for children aged 6-59 months.

  - Conclusion: the introduction of systematic influenza vaccination in children aged 6 to 59 months has not been shown to be associated with a reduction in influenza cases in primary care or hospital settings during the early stages of implementation of the new vaccination program. Longer follow-up and higher vaccination coverage are needed to confirm population-level impact.

  
  

  64. Opinion/interpretation: some physicians reviewing this body of evidence (e.g., Dr. Paul Marik, drawing on the Cleveland Clinic and mFLUSIVA data above) have concluded the vaccine may be ineffective, or even negatively effective, in some populations and seasons. This is one interpretation of mixed data rather than a settled finding — CDC network data most seasons shows modest positive effectiveness, while single-institution studies and reanalyses like the ones above have shown null or negative results. Readers should weigh both.

  
  

  How many people die of the flu?

  CDC's estimates of overall flu deaths have ranged in recent years from 36,000 for the 1990-1991 flu season to 80,000 for the 2017-2018 flu season. HHS mortality and morbidity data available on the National Center for Health Statistics (NCHS) website show CDC's annual estimates are off by orders of magnitude. NCHS data report the average number of mortalities attributable to influenza alone on death certificates is little more than 1,000. CDC's inflated estimate comes from conflating flu deaths with pneumonia deaths, most of which are unrelated to the flu. Subtracting pneumonia, the true number of influenza-associated deaths from 1979 to 2002 averaged 1,348, according to NCHS data. Media routinely reports figures forty times this number. Pediatric flu deaths are individually reportable and range from 60-120 annually; adult flu deaths are not individually reportable and are estimated from death certificates.

  
  

  What is the best way to prevent the flu?

  The Cochrane Collaboration's 2010 meta-analysis of published influenza vaccine studies found the influenza vaccination has no effect on hospitalization, and no evidence vaccines prevent viral transmission or complications. The Cochrane researchers concluded in 2010 that the scientific evidence discourages routine use of influenza vaccination in healthy adults as a public health measure; a 2014 follow-up meta-review of dozens of additional studies reached the same conclusion, reaffirmed again in 2018.

  
  

  Can the flu shot transmit the flu?

  A January 18, 2018 study in PNAS found that influenza vaccination was associated with increased transmission of the virus, with vaccinated individuals shedding more than six times as much aerosolized virus in their breath than unvaccinated individuals. The researchers suggested certain types of prior immunity — specifically vaccine-conferred immunity, as opposed to naturally acquired immunity — may promote lung inflammation, airway closure, and aerosol generation. If confirmed, this observation, together with literature on reduced protection with annual vaccination, could have implications for vaccination recommendations and policy.

  
  

  Should you get the flu shot if you are concerned about the coronavirus?

  Limited studies have assessed flu shots and coronavirus risk. A January 2020 US Pentagon-funded study found an association between flu vaccination and a 36% increased risk from coronavirus (virus interference). Only about 7-15% of "influenza-like illnesses" are actually caused by influenza viruses; some research suggests the flu vaccine may increase vulnerability to the remaining 85-93% of non-flu respiratory infections. A 2011 study of healthy Australian children published in the Pediatric Infectious Disease Journal found seasonal flu shots increased the risk of flu by 73% and doubled the risk of non-flu respiratory infections. A 2012 randomized controlled trial in Clinical Infectious Diseases similarly found influenza-vaccinated children had no significantly lessened risk from influenza and a higher risk of non-influenza viral infection. An April 2010 study in PLoS Medicine reported that receipt of the 2008-2009 seasonal influenza vaccine, while apparently effective against seasonal flu, was associated with increased risk of illness from the pandemic H1N1 virus during spring/summer 2009 in four Canadian epidemiologic studies. A 2011 Journal of Virology study confirmed annual influenza vaccination hampers development of robust cell-mediated immunity in children, potentially rendering previously unexposed children more susceptible to a novel pandemic strain. A 2018 CDC-funded study found an increase in acute respiratory infections from non-influenza pathogens following vaccination compared to unvaccinated children in the same period. A CDC-funded study published in September 2014 in Clinical Infectious Diseases, examining five years of vaccination data, found vaccine-induced protection was greatest for individuals not vaccinated during the prior five years, with effectiveness declining with repeated annual vaccination.

  
  

  Conclusion

  In their 2010 meta-analysis, the Cochrane researchers noted discrepancies between the CDC's public messaging and the underlying science supporting universal influenza vaccination recommendations. The CDC holds multiple vaccine patents and generates revenue connected to vaccines, which represents a potential conflict of interest. Multiple federal investigations and whistleblower reports have examined the relationship between CDC's Vaccine Branch and vaccine manufacturers, including a 2000 US Congress Government Oversight Committee report, a 2009 HHS Office of Inspector General report, a 2014 letter from the Director of the HHS Office of Research Integrity, and a 2011 letter from a group of CDC scientists to CDC leadership.

  
  

  Medicolegal Disclaimer

  The above constitutes an opinion for educational purposes only and is in no way to be interpreted as medical advice.