Title: EFFICACY AND EFFECTIVINESS OF INACTIVED INFLUENZA VIRUS VACCINE
1EFFICACY AND EFFECTIVINESS OF INACTIVED
INFLUENZA VIRUS VACCINE
2Factors influencing vaccine efficacy
- Closeness of the match between the vaccine strain
and the circulating virus - Age of vaccinee older people do not respond as
well - Health of the vaccinee people with chronic
illnesses and immune system disorders do not
respond as well as healthy individuals - Number of vaccinations regular annual
vaccinations improve the protection compared with
the first year of vaccination - Type of vaccine used
3Efficacy of influenza vaccination in healthy
adults
- Prevention of influenza infection
- Recommended inactivated parenteral vaccines
- Efficacy 70
- Effectiveness 25
- Recommended live aerosol vaccines
- Efficacy 48
- Effectiveness 15
Demicheli V et al. Cochrane Database Syst Rev
2004 3 CD001269.
4Efficacy of influenza vaccination in elderly and
high-risk persons
- Prevention of illness and death
- Among high-risk adults (e.g. patients with
chronic cardiovascular, respiratory or renal
disease) 1864 years, vaccination prevented1 - 78 of deaths
- 87 of hospitalisations
- 26 of GP visits
- Among elderly individuals (gt 65 years),
vaccination prevented1 - 50 of deaths
- 48 of hospitalisations
1. Hak E et al. Arch Intern Med 2005 165 27480
5Efficacy of influenza vaccination in elderly and
high-risk persons
- Prevention of illness and death
- Among community-dwelling elderly individuals,
influenza vaccination prevented 1 death for every
302 vaccinees at vaccination coverage between 64
and 74
Voordouw AC et al. JAMA 2004 292 208995.
6Efficacy of influenza vaccination in elderly
persons
- In a meta-analysis of 20 cohort studies, pooled
estimates of vaccine efficacy demonstrated
prevention of morbidity and mortality during the
influenza season - Respiratory illness 56
- Pneumonia 53
- Hospitalisation 50
- Death 68
The studies confirm the effectivenessof
influenza vaccine
Gross PA et al. Ann Intern Med 1995 123 51827.
7Influenza deaths versus vaccination history
WHO Collaborating Centre for Influenza, Melbourne.
8Influenza vaccination inpatients with CHD
- Case control study of 218 patients with coronary
heart disease (CHD) during the 199798 influenza
season in the USA - Efficacy of influenza vaccine in reducing the
risk of recurrent myocardial infarction (MI) in
patients with CHD
Vaccination associated with a reduced risk of
recurrent MI
Past and current influenza vaccination
reducesthe risk of recurrent MI in CHD patients
Naghavi M et al. Circulation 2000 102 303945.
9Influenza vaccination inindividuals with asthma
- No significant increase in asthma exacerbations
in the 2 weeks following influenza vaccination - Based on pooled results of two trialsinvolving
2306 individuals with asthmain a Cochrane review - No significant reduction in influenza-related
asthma exacerbations - Based on a recent study of 696 childrenwith
asthma
Cates CJ et al. Cochrane Database Syst Rev 2004
2 CD000364.
10Years of life bought forUS1 million (1990
dollars)
- Pap smear every 3 years 52 life-years
- Bypass surgery for left main 134
life-yearscoronary artery disease - Pneumococcal pneumonia 100 life-years
vaccination - Influenza vaccination 11,100 life-years
Influenza vaccination is a highly cost-effective
healthcare intervention
Russell LB. Health Aff (Millwood) 1992 11 1629.
11By courtesy of APACIAsia-Pacific Advisory
Committee on influenzawww.apaci-flu.com