Influenza Transmission:
- Seasonal influenza is easily transmitted through:
- Inhalation of infected droplets in the air from an infected person while coughing or sneezing.
- Touching surfaces contaminated with the influenza virus and then touching eyes, nose or mouth.
- The period for transmission ranges from one day before the onset of symptoms to 5-7 days thereafter. It can also last for a longer period in children and immunodeficient persons.
- To avoid transmission, people should follow cough etiquette (cover their mouth and nose with a tissue when coughing or sneezing), and wash their hands regularly.
Influenza Prevention:
- The most effective way to prevent the disease and/or its severe complications is to keep taking the vaccine annually.
- Safe and effective vaccines are available and have been used for more than 60 years. Among healthy adults, influenza vaccine can provide up to 90% protection, the vaccine may reduce severity of disease by 60% amongst the elderly and incidence of complications and deaths by 80%.
- There are two types of influenza vaccines:
- Influenza vaccine by injection: it is a vaccine that contains inactivated virus (Inactivated Vaccine), injected to people aged 6 months and above, including healthy adults, pregnant women and those suffering from chronic diseases.
- Influenza vaccine by nasal spray (Nasal-Spray Flu Vaccine): a vaccine that contains a live weakened virus vaccine that does not cause influenza infection. This is given to people between the age of 2 years to 49 years and is not given to pregnant women, children under two years nor the elderly over 65 years.
- The immune system produces antibodies to fight the virus after taking the vaccine, which may take two weeks after that the body acquires protective immunity against seasonal influenza infection. However, it does not result in the prevention of infection with other microbes that cause similar symptoms.
- There are two types of vaccines, one for the northern hemisphere and another for the southern hemisphere, depending on the types of influenza viruses common in either case.
- The influenza vaccination is most effective when the vaccine provided closely matches the circulating viruses each year. Due to the frequently changing nature of the flu viruses, the WHO monitors the influenza viruses that are spreading amongst humans in both hemispheres throughout each year and recommends a vaccine for those strains accordingly.
- currently trivalent influenza vaccine (TIV), it contains (2 flu A strains and one B), quadrivalent vaccine become recently available, it contains (2 flu A, 2 flu B) strains.
Side Effects of Vaccination:
- Influenza vaccination is safe, but is possible to be accompanied by some temporary, local symptoms that appear for no more than 48 hours, such as:
- Mild redness or swelling at the injection site.
- Slight rise in temperature.
- Minor body aches.
- Sore throat.
Contraindications to Influenza Vaccination:
- The following groups should be vaccinated only after consulting a doctor:
- Those who have severe egg allergy.
- Those with previous history of severe allergy to influenza vaccine.
- Those with history of Guillain Barre Syndrome after taking the vaccine.
- Children under 6 months (vaccine is not approved for this category).
- People suffering from very high or moderate temperature (they may be vaccinated after recovery)