No 39 - 2011
Seasonal influenza vaccination 2011/2012
Seasonal influenza vaccination 2011/2012
Free influenza vaccination
In accordance with Executive Order of 4 July 2011 on free influenza vaccination to selected population groups, the following persons residing in Denmark are entitled to free influenza vaccination:
- Persons who at time of vaccination are aged 65 years or more
- Early retirement pensioners
- Chronically ill persons suffering from the following conditions are included upon medical assessment:
- Chronic pulmo nary conditions
- Cardiovascular diseases (barring high blood pressure with no concurrent conditions)
- Diabetes 1 or 2
- Congenital or acquired immunodeficiency
- Patients whose respiration is affected due to muscular weakness
- Chronic liver and kidney failure - Severe obesity (BMI > 40)
- Persons with other serious diseases that, according to doctor’s assessment, pose a serious health risk in conjunction with influenza.
- Pregnants in 2nd or 3rd trimester
- Household contacts of severely immunosuppressed persons.
The National Board of Health has prepared a guideline on free influenza vaccination (published with the executive order and available at www.sst.dk (Danish language)
The offer of free vaccination is valid as from 1 October until end 2011. For pregnants in 2nd and 3rd trimesters, the offer remains valid until 1 March 2012.
Information
The National Board of Health has sent out information letter and posters to Danish GPs, municipalities, pharmacies and maternity wards along with information on free vaccination for risk groups.
As from week 39, information focused on risk groups will be distributed via ads, TV spots and public screens.
Children
Children > 6 months with a risk of a serious influenza course should be vaccinated. In the majority of cases, such children are monitored at a paediatric clinic, but they may also receive free vaccination at a specialist or at a vaccination clinic.
A guideline from the Danish Paediatric Society is available at the website www.paediatri.dk (Danish laguage).
Children aged 6 months - 8 years who have not previously been vaccinated should have two vaccinations at a minimum interval of four weeks. Children aged 6 - 35 months need only half the dose. It may be relevant to vaccinate household contacts and others in close contact with children belonging to the risk groups.
Pregnancy and breastfeeding
Vaccination is recommended for all pregnants in 2nd or 3rd trimesters. Pregnants belonging to one of the risk groups of chronically ill mentioned above should be recommended vaccination irrespective of stage of pregnancy. Experience with vaccination of pregnants has demonstrated no increased risk of congenital abnormalities or other pregnancy-associated secondary effects. The vaccine can be given during the breastfeeding period.Disseminated sclerosis and HIV
Patients with disseminated sclerosis are in risk of new attacks if complicated by influenza. However, new attacks as a result of vaccination have not been observed. Guidance on vaccination of HIV-infected patients is available from the infectious diseases department where the patient attends follow-up.The 2011/2012 season
The vaccines contain the primary strains of the three seasonal influenza viruses currently in global circulation:
- A/California/7/2009 (H1N1)-like virus (2009 pandemic virus)
- A/Perth/16/2009 (H3N2)-like virus
- B/Brisbane/60/2008-like virus The vaccines contain inactivated influenza virus components (split-virus vaccine), but no adjuvant/thiomersal.
The vaccines comply with WHO recommendation for the Northern Hemisphere for the 2011/2012 season.
Influenza vaccines from the previous season cannot be used due to limited in-use storage time.
Ordering and delivery
In 2011, four vaccine brands were ordered from three manufacturers. The vaccines are considered to provide equal influenza protection. Two of the vaccines are distributed as first-choice treatment for children and adults. The two other vaccines may be ordered in special cases.
A vaccine with no traces of chicken eggs/chicken protein, neomycin or gentamicin for persons > 18 years of age with verified type I allergy against one of these compounds can be ordered by phone.
Furthermore, an intradermal vaccine of limited volume (0.1 ml with an easy-to-use micro needle) is available for persons aged 18 to 59 years. This latter vaccine is more expensive than those previously mentioned.
Degree of protection
Immunity is achieved 2-3 weeks after vaccination, and is generally effective for a period of 6-12 months.The degree of protection is particularly depending on the correlation between the type of viruses in circulation and the virus strains in the vaccine. In young, healthy persons, vaccination prevents 70-90% of influenza cases. In elderly persons, protection against ordinary influenza illness is somewhat lower. Protection against serious complications, hospital admissions and death in the elderly is up to 60%.
Adverse events & contraindications
Fever, malaise, rigours and tiredness are common reactions which will typically recede after 1-2 days. Vaccination does not cause influenza disease. Previous reactions including fever, swelling or soreness in association with pandemic vaccination (Pandemrix®) do not constitute a contraindication to seasonal influenza vaccination.
Persons who are hypersensitive to the vaccine’s ingredients and who previously experienced an anaphylactic reaction should not be vaccinated.
Persons > 18 years of age with verified type I allergy to eggs, neomycin or gentamicin, may be offered a special vaccine, see above.
Formaldehyde allergy will most frequently manifest itself as contact dermatitis in connection with which patch tests may be positive; this does not comprise a contraindication. To avoid this, the vaccine may be administered intramuscularly.
Neuroaminidase inhibitors may be used prophylactically in persons who are unvaccinated due to contraindications and in any unvaccinated contact persons.
(T.G. Krause, S. Glismann, L.K. Knudsen, Department of Epidemiology)
28 September 2011