Haemophilus influenzae type b (Hib) vaccine was licensed for use in infants in 1991. However, developing countries delayed its introduction due to cost and because Hib disease was perceived to be relatively rare. In 2001, Kenya was one of nine countries to receive financial backing to introduce the vaccine. How cost-effective has it been?

Researchers led by the Kenya Medical Research Institute (KEMRI) estimated the cost-effectiveness of delivering the Hib vaccine in Kenya. The vaccine was financed by GAVI (previously the Global Alliance for Vaccines and Immunization). It was incorporated into Kenya’s routine infant immunisation services within the pentavalent (five-in-one) vaccine which also includes diphtheria, tetanus, pertussis (whooping cough) and hepatitis B. Recently the Kenyan government agreed to co-finance the costs of the vaccine from 2006 to 2011, gradually increasing its contributions.

The researchers compared the current costs of delivering the pentavalent vaccine against the combination vaccine without Hib. They took the current price of US$3.65 per dose of pentavalent vaccine and estimated costs for the public health provider, without including costs incurred by households. They then estimated the impact of the vaccine on incidence of Hib disease among children born in 2004, adjusting data to account for surveillance problems resulting from poor access to healthcare.

Findings suggested that following the introduction of the vaccine, the cost of averting one year of life lost due to disability was US$38 (less than per capita gross domestic product) while the cost per life saved was US$1,197. The price at which the government health sector would break even (where Hib vaccination costs would equal treatment costs averted) was US$1.82 per dose of pentavalent vaccine. Estimates also suggested that introducing Hib vaccine would:

• reduce incidence of Hib meningitis from 71 to 8 per 100,000, and of Hib non-meningitic invasive disease from 61 to 7 per 100,000 children aged under five
• reduce incidence of non-bacteraemic Hib pneumonia (the most common form of the disease in developing countries) from 296 to 34 per 100,000 children aged under five
• reduce the overall number of cases of Hib disease from 27,347 to 3,149 and the number of deaths from 6,112 to 704 per year
• prevent 5,408 deaths among children born in 2004 over the first five years of life (four percent of under-five mortality)

They conclude that Hib vaccine is a highly cost-effective intervention in Kenya. Although the level of disease is relatively low, the investment required for disease prevention is also low. This analysis should encourage action in countries that have delayed vaccine introduction because the costs did not appear to be matched by the benefits. They stress that:

• Each life saved requires a similar level of investment to that needed for impregnated bed nets.
• A small decrease in vaccine price greatly improves cost-effectiveness.
• The pentavalent vaccine would be affordable to all at half the current price per dose.
• A price lower than half the current cost per dose of pentavalent vaccine would result in government health sector savings.

Source(s):
‘Economic evaluation of delivering Haemophilus influenzae type b vaccine in routine immunization services in Kenya’, Bulletin of the World Health Organization, Vol 85, Number 7, pages 511-518, by Angela Oloo Akumu, Mike English, J. Anthony G. Scott and Ulla K. Griffiths, 2007 Full document.

Funded by: World Health Organization (WHO)

id21 Research Highlight: 5 April 2008

Further Information:
Ulla K. Griffiths
London School of Hygiene and Tropical Medicine
Health Policy Unit
Keppel Street
London WC1B 3DP
UK.

Contact the contributor: ulla.griffiths@lshtm.ac.uk

Health Policy Unit, London School of Hygiene and Tropical Medicine

Kenya Medical Research Institute (KEMRI)

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'Adverse effects of mass vaccination in Brazil: the case of MMR'