BusinessWeek Online
Two Virus Whizzes Talk about SARS
Friday April 11, 9:38 am ET
SARS, or severe acute respiratory syndrome, probably had its origins in chickens, cows, or some other animal. The suspected pathogen is known as a coronavirus, so-named because of its unique shape, and it has so far killed at least 106 people and infected more than 3,000, including at least 100 nonlethal cases in the U.S. [see BW Asian Cover Story, 3/14/03, "Deadly Virus"]. Efforts to keep SARS from spreading rapidly throughout the world threaten to wreak havoc on the global economy because it seems to be spreading by way of air travel.
While no treatment yet exists for SARS, early detection and hospitalization can vastly increase a victim's chances of survival -- to greater than 95%. Officials in mainland China, where the virus most likely originated, said on Apr. 8 that the disease appears to be spreading more slowly -- though the number of infections continues to escalate in Hong Kong [see BW Online, 3/11/03, "How SARS Is Strangling Hong Kong"].
So, it's still possible that SARS could turn into a global health emergency. On Apr. 7, BusinessWeek Online Reporter David Shook spoke with two acclaimed experts in the study and treatment of viruses: Thomas Monath, chief scientific officer at Acambis (NasdaqNM:ACAM - News), a Boston biotech company that's developing a vaccine for smallpox and West Nile virus; and Kathryn Holmes, molecular biologist for the University of Colorado [Denver] Health Sciences Center and an expert on coronaviruses. They talked about the possible cause of SARS, how the private sector might help, and what still needs to be discovered before a significant medical advancement against SARS can be achieved. Edited excerpts of the two interviews follow:
Q: Until now, coronaviruses were known to cause serious epidemics in animals but only mild infections in humans. What may have caused this strain of coronavirus to emerge or change in such a way that it's now deadly to humans?
Holmes: There's still much we don't know, but generally, coronaviruses can mutate very easily, and mutations can lead to higher virulence, or in rare instances allow the virus to "jump" to a different kind of host [such as jumping from an animal host to a human].
Coronaviruses have been know to steal a gene from a totally unrelated virus, changing its virulence. But for that to happen, the two unrelated viruses would have to infect a cell at the same moment, allowing the coronavirus to incorporate a copy of RNA of the other virus into its own genome.
Q: But right now we don't even know if this is a known coronavirus or some completely new one, correct?
Holmes: That's right. Did the virus jump from an animal host to humans just once, or has it jumped several times from animals to humans? We know there are three types of coronaviruses. Does this one fit into one of these existing groups, or is it a totally new one? Those questions must be answered.
Q: Do you think the drug industry will create a vaccine to fight it?
Monath: A vaccine can be developed, but it will take years to do it, to sequence the proteins of the virus, clone the gene encoding the protein that can lead to immunity, and then create a vaccine from there.
Q: Is that the simplest way to make a vaccine?
Monath: The simplest way is to grow the virus in a lab and then kill it, much like the old polio virus was grown and then killed. But that effort would require a special containment facility and vaccine plant to grow the virus and produce the vaccine. It's something that requires a great deal of caution to handle.
It's important to note that at this point, we don't even know if SARS is a flash in the pan or a serious problem that will march across the globe -- creating a clear commercial need for a vaccine. At some point, if it does become a huge problem, we'll see the government and the industry making tough decisions on shifting significant resources to SARS research. That hasn't happened yet.
Q: What are the most likely companies to take part in SARS vaccine research if it becomes necessary?
Monath: More than a dozen biotech companies have been involved in development of drugs to treat hepatitis and HIV that could get involved, or the major vaccine makers Aventis (NYSE:AVE - News), GlaxoSmithKline (NYSE:GSK - News), or Wyeth (NYSE:WYE - News).
Q: When you look at the spread of SARS, how would you put this epidemic in perspective, considering the many scourges you've seen in your career as a virologist?
Holmes: I think it's important to remember that more than 2 million die of tuberculosis each year, and 20,000 to 40,000 people in the U.S. alone die each year from influenza. Outbreaks of the Ebola virus have killed more people than SARS this year. And HIV kills nearly every one of its victims who are left untreated. You have to keep these things in mind.
Q: How would you characterize the public-health effort to contain SARS thus far?
Monath: It's clear that we're so much better prepared to recognize this kind of threat and to react quickly. We've already seen diagnostic tools developed to identify the coronavirus thought to be responsible for the disease. I think this will be a wonderful example of how the worldwide public-health community can work together to contain a major threat.
Holmes: The very good news about the public-health efforts for SARS is the unbelievable response by 11 laboratories coordinated by the World Health Organization that are now working together on ways to contain the outbreak and study the virus. These organizations are literally sharing information on a daily basis. That's unprecedented.
The technological advances in the characterization of viruses and sequencing of the virus genome have given rise to diagnostic tests for SARS virus just three weeks after the first reports of the outbreak. That's remarkable. In a couple of weeks, the genome of this virus will be known. It may then be possible to tell where it came from.
It's important that these organizations have been able to work this fast and so closely. The fact is that Nature is always experimenting. So, there'll always be another emerging infectious-disease threat that may cause a major health problem. Science's ability to respond this rapidly is crucial to keeping it in check. |
