Reversing a downward trend, immunization rates are now at their highest ever and vaccine development worldwide is booming, according to a new assessment released by the World Health Organization (WHO), UNICEF and the World Bank.

The State of the world’s vaccines and immunization reports that more infants are being immunized today than ever before - a record 106 million in 2008 - according to new data. At the same time, its authors are calling on donor nations to address a funding gap that leaves millions of children still at risk, particularly in the poorest nations and communities, where preventable diseases take their deadliest toll

The release of new evidence of success in the overall global immunization effort takes place just as many nations are conducting pandemic influenza A (H1N1) immunization campaigns, underscoring the unparalleled role of vaccines in preventing communicable diseases and the challenges of reaching the most vulnerable communities.

"The influenza pandemic draws attention to the promise and dynamism of vaccine development," said Dr Margaret Chan, director-general, WHO. “Yet it reminds us once again of the obstacles to bringing the benefits of science to people in the poorest nations. We must overcome the divide that separates rich from poor - between those who get life-saving vaccines, and those who don’t."

Leading officials from international agencies warn that life-saving vaccines, now common in wealthy countries, still do not reach an estimated 24 million children who are most at risk. At least an additional US$ 1 billion per year will be needed to ensure that new and existing vaccines will be delivered to all children in the 72 poorest countries.

"Worldwide measles deaths fell by 74 per cent between 2000 and 2007, and vaccinations played an important part in that decline," said Ann M Veneman, executive director, UNICEF. “Such progress must inspire new efforts to immunize children around the globe against life-threatening diseases."

The report states that the reversal of the downward trend was in great part due to the efforts of developing countries, who made good use of support from the GAVI Alliance - a vaccine-financing partnership that includes WHO, UNICEF, the World Bank and the Bill & Melinda Gates Foundation. Since 2000, this has increased the introduction of new and underused vaccines, which now reach more than 200 million children in developing countries.

Experts report that at least 120 vaccines - a record number - are now available against deadly diseases. Over the last few years, scientists in academia and at pharmaceutical companies, many in public-private partnerships created with support from governments and philanthropy, have developed new life-saving vaccines for meningococcal meningitis, rotavirus diarrhoea, pneumococcal disease, and human papillomavirus (HPV). In addition, over 80 new products are in late-stage clinical testing, including more than 30 that target diseases for which no vaccine currently exists. At the same time, a significant number of vaccine candidates, including ones targeting diseases such as HIV/AIDS, malaria, tuberculosis and dengue, are moving through the research pipeline.

The report also notes that the global vaccine market has tripled over the last eight years, reaching more than US$ 17 billion in revenue. Rising demand for vaccines via United Nations procuring agencies and a renaissance in vaccine discovery and development have fueled industry’s renewed focus on vaccines. Significantly, manufacturers in developing countries are now meeting 86 % of the global demand for traditional vaccines, such as those protecting against measles, whooping cough (pertussis), tetanus and diphtheria.

"We have seen a dramatic turnaround in the availability of vaccines in even the poorest countries," said Graeme Wheeler, managing director, World Bank Group. "Yet the international community, together with the countries themselves must ensure that new and existing technologies actually reach the most vulnerable populations, especially children."

The cost of delivering vaccines to those that need them is increasingly an issue that is only partially solved by financing partnerships such as GAVI. Middle income countries are not eligible for GAVI assistance, yet they are home to 30 million children and two billion people, a large number of whom live on less than US$ 2 per day. Even at greatly reduced prices, the cost of new vaccines for pneumococcal disease, rotavirus diarrhoea and HPV are individually greater than the cost of all other traditional vaccines combined.

"Vaccines are an incredible tool to control disease in all countries and are still a very smart buy in health and economic terms," said Dr Fred Were, National chairman of the Kenya Paediatric Association. “Practicing in my country, we still unfortunately see a lot of illness and death from vaccine-preventable diseases. If this can be reduced we will have more resources and time to focus on other health issues."