Of all health interventions, vaccination is among the most cost-effective. Through the Expanded Program on Immunisation (EPI), diseases such as polio, tetanus and measles are now in decline, and in some cases close to being eliminated.

The development of effective vaccines against other diseases of poverty such as malaria could save hundreds of thousands of lives each year, and bring the Millennium Development Goals a step closer.

Achieving this vision requires scientific research, to understand the diseases and create effective vaccines against them. Challenges here, especially with evasive parasites, can be severe.

Success will also require rigorous testing of potential vaccines in clinical trials, with uptake by industry for licensing, production and distribution. Issues of access and affordability then dominate, often demanding innovative approaches.