Breakthroughs in technology, increased funding and higher profits are spurring a boom in vaccine discovery and development that could save or improve the lives of millions of people by attacking such scourges as cancer and malaria.
Three new vaccines arrived on the market in 2006, the most in a single year. They include vaccines for the human papillomavirus, linked to cervical cancer, and for rotavirus, which causes severe diarrhea and kills 600,000 children globally each year. Another prevents shingles in the elderly.
As early as the end of the decade, scientists say, there may be new immunizations against herpes simplex and rheumatoid arthritis and a better seasonal influenza vaccine.
Researchers also are talking about a potential vaccine within five years to fight malaria -- long one of mankind's deadliest and most elusive adversaries.
Other scientists are making progress with what are known as therapeutic vaccines, which fight already diagnosed diseases or conditions, including cancer and Alzheimer's, or addictions to substances such as nicotine, by "teaching" the body to fight back. They're further down the road but hold the potential to transform medical care, experts say.
"It may turn out we have a perfect storm here of several different things coming together at the right time. This is a tremendous time of opportunity for both the developed and the developing world," said David Fleming, director of the Bill & Melinda Gates Foundation's global health strategies program, which has made vaccine development and access a cornerstone of its mission.
"It's clear there is a renaissance going on around vaccines," said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases. "We have made more progress with some [vaccines] in the past few years than we have in the past 30."
The current immunization boom could rival or even surpass the Golden Age of vaccine development between the late 1940s and early 1960s, experts say, when scientists such as Jonas Salk discovered inoculations for polio, flu, mumps and measles. But relatively few vaccines were found in the decades that followed, partly due to lack of profitability for drug companies and reduced vaccine research funding.
Perhaps the best evidence of a vaccine revival is that the pharmaceutical industry is returning to the market.
Drug giant Pfizer Inc., which shuttered its human vaccine unit in 1976, reopened it in the fall by acquiring a small British vaccine company. Even with planned layoffs announced last week, Pfizer says it intends to increase funding in its vaccine business.
Novartis and GlaxoSmithKline recently have invested billions expanding their vaccine trades by buying up smaller players and expanding research programs.
Jean Stephenne, president of GlaxoSmithKline Biologicals, expects his company to have five new vaccines in the next five years and that its vaccine business will grow from 6% of the company's sales this year to 14% by 2010.
Overall, the number of vaccines in development has risen from 285 in 1996 to 450 today.
Drug executives say they can charge considerably more for today's vaccines -- up to several hundred dollars or more -- versus a few dollars for older vaccines.
Prevnar, a vaccine introduced in 2000 to treat pneumococcal pneumonia -- the cause of up to a quarter of all community-acquired pneumonia cases each year -- runs about $250 for a four-shot series. It became the first vaccine to clock $1 billion in annual sales, giving it so-called blockbuster status.
Overall, the vaccine industry rang up $10 billion in sales in 2005, up from $6 billion in 2002. The market is estimated to reach $15 billion by the end of the decade.
Other factors increasing industry confidence in the sector: more funding from donors like the Gates Foundation, and novel proposals for increased vaccine research.
Typically, Third World countries can't afford to buy new vaccines and don't get access to them until a generation after their introduction, if ever. The lack of potential profits has blunted many drug companies' interest in researching and producing vaccines to treat diseases, such as malaria, found predominantly in poorer countries.
But that is slowly changing. At the Group of 8 summit in Russia last year, several countries proposed upfront financing for vaccine development, creating incentives for manufacturers.
And Geneva-based GAVI Alliance, a partnership created in 2000 that counts among its sponsors the United Nations, the World Health Organization and the Gates Foundation, is investing hundreds of millions of dollars to expand vaccine research and distribution.