Immunization

Immunisations against a range of major diseases from hepatitis to influenza can be highly cost-effective because they are easily accessible to the most needy populations and are easily administered. However, there is significant variation between different approaches, and most charities do not focus exclusively on the most cost-effective.

Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. Vaccines stimulate the body's own immune system to protect the person against subsequent infection or disease.

Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert over 2 million deaths each year. It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations. It has clearly defined target groups; it can be delivered effectively through outreach activities; and vaccination does not require any major lifestyle change.1

Cost-Effectiveness

Intuitively, immunizations would seem to be a likely candidate for a highly cost effective intervention type. Indeed, the WHO claim, “Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert over 2 million deaths each year. It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations.”2 They are also recommended by the Copenhagen Consensus.

However, the results of the DCP2 and WHO-CHOICE reports suggest that though some immunization interventions are cost-effective, many are much less cost-effective.

We have been unable to find many cost-effectiveness estimates from charities which focus on immunization. The exceptions are Measles Initiative, which estimates that a single vaccination for measles costs less than $1, and Global Polio Eradication Initiative, which estimates that a single vaccination for polio costs $0.08.

The DCP2 and WHO-CHOICE cost-effectiveness estimates are as follows:

In understanding the DCP2 figures, it is important to note the contrast in cost-effectiveness between the pentavalent vaccine, the expanded program and the measles vaccine. The pentavalent vaccine consists of five vaccine treatments: Haemophilus influenzae type B (HiB), hepatitis B, diphtheria, pertussis (whooping cough), and tetanus. The expanded program consists of diphtheria, tetanus, pertussis, polio, measles, and the BCG. The pentavalent vaccine and the expanded program treat very similar diseases; however, only the latter treats measles. It is therefore possible that, in the expanded program, it is the vaccination against measles that is responsible for almost all the cost-effectiveness.

Another point to note is that it is likely that the DCP2's measles cost-effectiveness estimate is optimistic, as the number of cases of measles has been declining rapidly since the report, which suggests that cost-effectiveness will similarly decrease.

Note that the DCP2 estimate for measles vaccination is the benefit of providing a centralised clinic for a 'second chance' vaccination. In other words, for people to visit and be vaccinated if they missed the opportunity to be vaccinated in their villages. According the the DCP2, this is a particularly effective method, with each $1,000 preventing 250 Disability Adjusted Life Years, which is roughly on a par with saving 8 lives. The WHO-CHOICE estimate (which doesn't specify whether it is a second chance, a first chance, or mixed) is that each $1,000 spent on measles vaccination would save around 30 DALYs, or the equivalent of 1 life.

Other Information

Are there side-effects?

All health interventions have side-effects, both good and bad.

Some of the positive side-effects of immunization include:

• Vaccination does not require any major lifestyle change, and there is very little cost to the recipient, in terms of travel costs and working hours lost.
• They have economic benefits, as these diseases can severely impair the ability to work.

One negative side-effect is:

• Some of the vaccinations have very small risks of medical side-effects.

Conclusion

It is important to know which immunizations an immunization charity is providing. Many do not focus merely on the traditional expanded program but also fund pentavalent vaccination programs, so they divide their expenditure between highly cost-effective and much less cost-effective interventions. We have yet to find a charity that focuses solely on the most cost-effective vaccinations.

In general, we don't have sufficient evidence that immunization programs, as they are carried out by charities, are cost effective enough for us to recommend them.