Consider the progress that has been made with the lifesaving pentavalent vaccine, which protects a child against diphtheria, tetanus, whooping cough, hepatitis B, and haemophilus influenza type b (Hib)- all in one dose. When the GAVI Alliance first introduced it in 2001, there was one supplier and the cost was $3.50 per dose. As demand for the vaccine grew, GAVI encouraged other suppliers to enter the market, and the price tumbled. Now there are five suppliers, and Biological E, an Indian pharmaceutical company, announced earlier this year that it would offer the vaccine for just $1.19 per dose.

We have also seen major emerging countries invest in biomedical technology to supply developing countries with new vaccines. India's Department of Biotechnology and Bharat Biotech announced plans this year to release a new vaccine against rotavirus - which kills hundreds of thousands of children - for $1 per dose, significantly cheaper than existing vaccines. Likewise, a Chinese biotech company won approval in October from the World Health Organization to bring to market an improved vaccine protecting children against Japanese encephalitis. The same month, Brazil's top biomedical research and development center, Bio-Manguinhos, in partnership with the Gates Foundation, announced plans to produce a combined measles and rubella vaccine.

When I first got involved in global health more than 15 years ago, these kinds of announcements were rare. The vaccine field was dominated by a handful of multinational pharmaceutical companies in rich countries, and the entire sector suffered from a lack of competition. Today, emerging-country manufacturers produce about 50 percent of vaccines purchased by United Nations agencies for use in the developing world, up from less than 10 percent in 1997.

The contributions of emerging-country vaccine producers often complement the work of their counterparts in developed countries. In fact, some of the most innovative ideas have come from their combined efforts. The Gates Foundation supported a major partnership between the Serum Institute of India and SynCo Bio Partners, a Dutch vaccine producer, to produce a low-cost vaccine to protect more than 450 million people in Africa from meningitis. This year, Biological E announced two major partnerships with multinational vaccine manufacturers. A joint partnership with GlaxoSmithKline will produce a six-in-one vaccine protecting children against polio and other infectious diseases; another, with Novartis, will produce two vaccines that will protect millions of people in the developing world from typhoid and paratyphoid fevers.

Despite all of this progress, more must be done to target the 22 million children, mainly in the poorest countries, who do not have access to lifesaving vaccines. Without protection against deadly diseases like measles, pneumonia, and rotavirus, many of these children are being denied a chance to grow up healthy, attend school, and lead productive lives. Their countries lose, too. Disease robs a poor country of the energy and talents of its people, raises treatment costs, and stymies economic growth.

We live in a world where we have the power to correct this injustice. We have the know-how to produce effective vaccines, make them affordable, and deliver them to the children who need them. Emerging-country vaccine suppliers are a critical part of this process. Thanks to their contributions, we are moving closer to the day when all children can have a healthy start to life.

The author is co-chair of the Bill and Melinda Gates Foundation.

Project Syndicate