SARS wars: Genomics may save China
Thank goodness that SARS (Severe Acute Respiratory Syndrome) arrived in the Genomics Age. The malady has already infected 5,000 people and killed 327 since it broke out in China last year. A decade ago, scientists would likely not have a clue yet about what was causing the deadly disease.
Prior to 1995, a few genomic sequences of viruses like HIV had been very laboriously and expensively completed. In 1995, the Institute for Genomic Research (TIGR), the private biotech company headed by Craig Venter in Maryland, began the Genomic Age by producing the first sequence of all the genes of a free living organism, the bacterium Haemophilus influenzae. This took 13 months and $900,000. But the pace of discovery in genomics quickly sped up.
Over the past eight years, the process of decoding genomes has become almost routine. Six years after the completion of the H. influenzae's 1.8 megabase (a megabase equals 1 million DNA bases) sequence, the first rough drafts of the 3,000 megabase human genome were announced in February 2001. Just this month, the international human genome consortium completed the final draft of the human genome.
Today, some gene-sequencing machines can read nearly two million DNA bases per day, so sequencing something like H. influenzae would ideally take a day rather than 13 months.
SARS appears to be caused by a new coronavirus, so called because their outer protein coats look like miniature crowns. They are responsible for about 20 to 30 percent of bad colds. Once the virus had been isolated and sent to Canadian researchers at the Michael Smith Genome Sciences Centre in Vancouver, British Columbia, it took them only six days (between April 6 and 12) to complete the virus' genetic sequence. The Centers for Disease Control and Prevention (CDC) in Atlanta announced its SARS sequence two days later.
"Research laboratories can use this information to begin to target antiviral drugs, to form the basis for developing vaccines, and to develop diagnostic tests that can lead to early detection," says Dr. Julie Gerberding, CDC's director.
And the race is on. At the beginning of April, the CDC released a test for the protective antibodies that patients develop as their immune systems fight the SARS virus. This test is not suitable for routine use, but can be employed by public health officials for finding and tracking people who might have been exposed to infected individuals.
Even as the SARS genetic sequences were being announced, researchers in Hong Kong, which has been hit especially hard by SARS, announced on April 15 that they had devised a diagnostic test which they believe can soon be used in doctor's offices for early detection of SARS.
The pharmaceutical giant Roche plans to have a commercial version of a SARS test available by July. Such diagnostic tests will enable physicians to separate out people who are suffering from some other respiratory illnesses and quickly isolate SARS patients so that they cannot pass along their disease to others. This kind of rapid progress is possible only because of biotechnological advances made in the past eight years.
The hunt is also on for antiviral drugs to treat people who have already been infected by the SARS virus. Unfortunately, scientists have yet to find many antiviral drugs that are as effective at killing viruses as antibiotics are at slaying bacteria.
So far medical science has generally had a better chance of dealing with viruses by vaccinating people before they are exposed to them, as with the polio, flu, and hepatitis vaccines. But even at the dawning of the Genomic Age, it would likely take two to three years to develop an effective SARS vaccine, largely due to the testing required to see if it works. Furthermore, biopharma companies have little incentive to develop such a vaccine unless the disease is likely to afflict millions of people.
If the epidemic can be contained soon, it simply would not be profitable for biopharma companies to develop a vaccine. Also, the SARS virus can apparently mutate quickly. Thus, a vaccine that protected a patient against an earlier version might not be effective against a newer one. However, as the Genomic Age matures and disease processes and human immune responses are better understood, vaccine production might profitably be speeded up and even become routine.
Despite all of the scientific and technological virtuosity evident in the rapid response to SARS, it wouldn't have been necessary if the Chinese government hadn't blundered in the first place by refusing to acknowledge the existence of the disease. An early quarantine would have cut the chain of infection, and the disease might well have died out.
However, Chinese officials evidently didn't want to mar the Chinese People's Congress meeting or frighten off tourists and investors. This denial gave the disease a chance to spread widely. Now Chinese officials are scrambling to quarantine people, which might still work. But fear of SARS is expected to cut China's growth rate by about 2 percent, costing its economy around $45 billion this year.
The moral of the story? No matter how smart the science and technology available, governments can always screw things up. The silver lining is that advancing science and technology can often cushion us from the even the stupidest government policies.
Downtown Charlottesville resident Ronald Bailey is Reason Magazine's science correspondent, as well as the editor of Earth Report 2000: Revisiting the True State of the Planet(McGraw-Hill).