Autumn has arrived and officially launches the annual flu immunization program. Many myths have developed over the years regarding the influenza vaccine. This article is written to dispel some of the myths associated with the annual flu vaccination by providing the facts.

1. The influenza virus will give me the flu.

  • The virus in the Canadian vaccine is killed and cannot cause influenza.
  • The killed virus is in pieces and cannot recombine into a live virus.
  • The antigens (mainly hemaglutin and neuraminidase) present in the vaccine induce immunity.
  • Other viruses that are circulating at the same time as the vaccine is given can cause colds and diarrhea… and these symptoms may wrongly be attributed to the vaccine
2. The influenza virus does not work.
  • The vaccine does work. In healthy children and adults, 70% to 90% efficacy (protection) is achieved when there is a good match to the seasonal strain – which is developed annually.
  • Immunization of health care workers decreases upper respiratory infections, physician visits and work absenteeism by 25% to 40% during seasonal influenza.
3. I don’t need to be immunized – I’m healthy!
  • Healthy adults account for most of the deaths in pandemics and represent a significant portion of deaths from pandemic H1N1.
  • Otherwise healthy children, younger than five years of age (notably those younger than two years of age) and adults older than 65 years of age are at significantly increased risk of hospitalization and complications from seasonal influenza.
  • Prevention of influenza will reduce risk of bacterial pneumonia
  • Health care workers can transmit virus to susceptible patients and their own families.
  • Studies have documented decreased transmission and decreased rate of death due to influenza in long-term care facilities where staff have been immunized.
4. Healthy children don’t need to be immunized – they’re healthy!
  • Healthy children are the epicentre of every yearly influenza epidemic.
  • Data shows that school immunization programs prevent adult deaths.
  • It is estimated that 15% to 42% of healthy preschool and school-aged children are infected annually with influenza.
  • Healthy children younger than 5 years of age are hospitalized as often as patients 50 to 64 years of age.
  • Infants younger that six months of age have the highest hospitalization rate
5. I might get those awful neurological side effects.
  • The influenza virus can itself cause many neurological effects (including encephalitis, meningitis, Reye’s syndrome, etc.)
  • When the swine influenza vaccine was administered in 1976, there was an increase of one extra case of Guillain-Barre syndrome (GBS) per 100,000 vaccinated. When this was recognized the vaccine was withdrawn and never used again. It is now known that a bacterial infection (Campylobacter) was the actual cause.
  • Canada has an excellent adverse events surveillance program for children and adults. If there is any increase in adverse events with the present influenza virus it will be detected quickly and responded to accordingly.
6. Thiomersal is bad and the mercury compound may cause autism.
  • Thiomersal in vaccines is a preservative and is metabolized to ethyl mercury, not methyl mercury (methyl is the toxic form of mercury). Thiomersal is regarded as safe.
  • Thiomersal is present in trace amounts in multi-dose vials of the vaccine. It is used to prevent bacterial contamination of vaccines. No thiomersal is present in single-dose flu vaccine preparations, however single-dose may not be available in all jurisdictions.
  • No evidence was found in numerous epidemiological studies that the trace amount of thiomersal in the vaccine is associated with autism or immune deficiency.
7. No one with an egg “allergy” should receive the influenza vaccine.
  • The virus is grown in eggs and the vaccine may contain minute amount of egg protein.
  • Individuals who can tolerate a small amount of cooked egg or eggs in baked goods can safely receive the vaccine in the physician’s office.
  • The risk of a serious reaction to the vaccine is considered extremely low compared with the risk of infection from the seasonal influenza.
  • Persons in the low-risk category should be vaccinated, but the patient should be observed for 60 minutes after vaccine administration. High-risk patients should have special precautions when administered by a physician.
8. I can’t be immunized because I‘m pregnant (or breastfeeding)
  • The Canadian Paediatric Society, the Society of Obstetricians and Gynecologists of Canada recommend that pregnant / breastfeeding women should be immunized.
  • The virus in the vaccine is dead, split and in pieces – so it cannot infect the woman or the fetus and is safe.
  • Antibodies from the mother are passed through the placenta to the fetus and provide some protection to infants younger than six months of age.
I have attempted to address the most common “myths” and/or reasons for not obtaining the flu vaccination by providing the documented facts. The more individuals that are vaccinated the less likely the “flu” season will affect you or a loved one due to the “herd effect”… a concept that has illustrated that the more individuals that are vaccinated in a community, the less chance that the very young, aged and very ill will experience the symptoms or complications of the flu.

Your family physician, Brant County Health Unit and local pharmacy can administer the flu vaccine.

Your Smith Drugs and Apothecary Pharmacist,

Norm Corriveau, BScPhm

(16 references available upon request)