Malaria kills as many as three million people yearly, but after
more than three decades of research
theres still no vaccine.
"Vaccine (for SARS) Could Be Ready in 1 to 3 Years, Scientists Say," blared the sub-headline of an article in the Washington Post. Worse was CBS Morning Show host Harry Smith asking guest Anthony Fauci, "Is there a chance therell be a vaccine by, say, next winter?" Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), politely replied, "I doubt (that) very seriously." A better response would have been to fall out of his chair.
On average it takes 10 to 15 years to bring a drug to market, according to a 1995 Tufts University study. (Not to mention about $800 million, according to more recent research.) But biotech has already sped up the SARS vaccine effort.
There are many steps towards developing a successful vaccine, one thats both safe and will prompt long-term immunity. The first is developing a "candidate" comprising proteins that will provoke the immune system. This stage has taken decades in some cases.
Biotech is changing this first with the development of genetic blueprints (called "sequencing") of pathogens. Indeed, several labs sequenced the SARS virus in a record ten days.
"That sequencing allows researchers to rapidly find target proteins," explains Paul Fischer, CEO of GenVec, Inc. of Gaithersburg, Md. His company has been given a grant by NIAID to develop SARS vaccine candidates.
"Further," he says, "were now able to bypass growing the pathogen itself in a lab. Instead, we take the information from the genetic sequence and make synthetic genes that will tell cells to produce proteins. We then insert those proteins into an inactivated cold virus."
These can quickly be tested in the lab to see if the proper proteins develop. In less than three months they may be ready for animal testing.
But SARS and other viruses produce several proteins, some of which may be worthless. How do we know which ones to test? "When you look at the genetic blueprint you can make certain inferences," says Fischer, adding that previous research on related viruses can also provide clues. Much of this can be done using "bioinformatics," applying computer analysis to genetic information.
The genome of the SARS virus was mapped in a mere 10 days.
At that point, vaccine candidates are sent on to animal testing. Here, too, biotech can help.
Lab animals are not little people. Notwithstanding the controversial new claim that chimps should be put in the same "family" as humans, even these animals can react far differently to a drug than humans. So scientists are genetically altering mice to make their immune systems more similar to ours.
But heres where the research normally slows dramatically, although it may be able to be speeded up in emergencies.
The FDA requires a three-stage process of human clinical trials for drug approval, vaccine or otherwise. In Phase I, a handful of volunteers are tested to see if the vaccine is safe. If so, the candidate goes on to Phase II where its evaluated for both safety and efficacy in a larger group.
Finally, in Phase III, a much larger group receives the vaccine primarily to determine if its effective in a high percentage of subjects. Sadly, many promising candidates fail in Phase III (and far more in the earlier stages) or even go through the entire process only to have the FDA reject them as either not sufficiently safe or effective.
The evaluation itself can take a year or more, although the grant of FDA "priority review" status usually shortens that to half a year.
Ultimately bioinformatics will take us through the entire vaccine development process, providing new vaccines at super speed with low development costs. Well use supercomputers that can imitate the immune system, just as some today can mimic nuclear blasts. Unfortunately, such bioinformatics computers are far beyond anything even on the drawing board.
Meanwhile, its best to remember that SARS has yet to kill a single American and to vaccinate ourselves against both false fears and hyped expectations.
Read Michael Fumentos other work on SARS.