At the World Economic Forum in Davos, Switzerland, last week, GAVI announced it would commit an additional $500 million over three years to strengthen healthcare systems in poor countries, a key problem in implementing vaccine programs in many locales. The organization says it has prevented 2.3 million deaths from disease since its inception, including 600,000 last year.
"The GAVI story is probably one of the greatest success stories of all time," Bill Gates said Friday in an interview with CNBC.
Vaccine access in industrialized countries can also be spotty. In the U.S., African Americans and Latinos have significantly lower immunization rates than other groups. And when a vaccine arrives on the market, it's not guaranteed to be covered by insurance.
While insurers deny it, doctors say the companies often wait a year or more before deciding to reimburse patients for a vaccine, hoping an initial surge of people will get immunized on their own dime.
This fall, Kelsey Boesch, 18, of Los Angeles paid about $300 for Gardasil, the vaccine against HPV. The three-shot regimen wasn't covered by her family's insurance.
"I hadn't heard about it, but when [my doctor] explained it to me, I didn't think twice," Boesch said.
Experts say mounting scientific and business momentum around vaccines could stall at any time, and several promising vaccine candidates remain in early clinical trials.
Last month, the federal government canceled its 5-year-old, $900-million anthrax vaccine program after the company failed to meet a deadline to test it in people. Vaccines for major killers like HIV, the virus that causes AIDS, and tuberculosis remain years, if not decades, away.
And drug companies have previously dipped their toes back in the vaccine market only to leave shortly after.
But even if only a handful of additional immunizations are found, it could have enormous impact on global health.
Malaria kills up to 3 million people a year. A less-fragile supply of flu vaccines could also have a major effect.
Vaccines are weakened or killed parts of bacteria or viruses that are injected into the body to stimulate antibodies that then provide immunity against that bacteria or virus.
Scientifically speaking, the last wave of vaccines half a century ago went after many of the "low-lying fruits but didn't help us with the more complex viruses and bacteria," said Warner Greene, director of the Gladstone Institute of Virology and Immunology at UC San Francisco.
