| |
Famed AIDS Researcher Is Racing to Find a Coronavirus Treatment
|
| |
| |
March 20, 2020
These are desperate times, tense, frightening, unnerving, particularly for HIV+ & older HIV+. Jules
Back https://www.bloomberg.com/news/features/2020-03-19/this-famous-aids-researcher-wants-to-find-a-coronavirus-cure
Columbia's David Ho is leading a group that's trying to compress a five-year process into one.
"It might take three to six months for Chavez to detect a few lead compounds that efficiently block coronavirus protease"
Scientists at Ho's lab, and at Johnson & Johnson, Pfizer, Regeneron, and at least 10 other drug and biotech companies, are working as quickly as they can to identify treatments. This virus is part of a family they've come to know. They're rushing to test old compounds even as they devise programs to create new ones. Among the furthest along is Gilead Sciences Inc., which is testing remdesivir, an antiviral drug tried on Ebola patients, on coronavirus patients around the world. Gilead expects to report initial results in April.
Scientists say they can tame this coronavirus, but for a while it will move faster than they'll be able to. It may be a year or more before any specific treatment for Covid-19 is available. Until then we'll have to contain it with distance and soap and the drugs we already have.
Even once there's a treatment, it's probable that Covid-19 will remain with us for longer than we'd like. Completely wiping out something this widespread is exceedingly difficult, Ho is quick to say. Only one such virus has been eradicated: smallpox. That took about 20 years.
"We're reading strange literature about bat research," Ho says. "Bats account for one-fifth of the mammals on this planet. That's trivia we didn't know. There are so many viruses that reside in bats—SARS and Ebola and perhaps this coronavirus." Covid-19 isn't the first, and it won't be the last. Ho wants to prepare for the next one now.
Hearing that was good enough for Jack Ma, the richest man in Asia. And it was sufficient for Zhi Hong, chief executive officer of Brii Biosciences, to also put in $2 million. Hong had been an infectious disease expert at GlaxoSmithKline Plc and has known Ho for years. "David has put together a quick but very reasonable program," Hong says. If Ho's lab comes up with a drug, a big pharmaceutical company would have to come in to test and produce it. There's no formal agreement yet about how that would happen. There was no time for lawyers. "Right now we're just investing in faith and trust in the relationship and David's reputation," Hong says. "We just said, 'Take the money.' "
The most straightforward of the lab's projects aims to find an antibody to block the virus from entering cells, either to prevent infection or to treat it. The first step was getting hold of specific white blood cells, called memory B cells, from patients who have recovered from Covid-19. These cells, named because they can remember a virus for decades, contain markers on their surfaces that allow the body to rapidly generate many antibodies to that virus. These antibodies help protect against Covid-19 infection. In late January, Ho called on his connections in Hong Kong to take blood samples from two convalescent patients. His New York staff spent days getting permission from the governments and arranging the shipping. The cells were purified, placed in tiny vials, frozen in liquid nitrogen at -150C, and sent to Ho's lab by a specialized courier service. They arrived intact in late February.
The chances that this research, or similar research elsewhere, will yield a treatment are relatively high. The strategy worked for Ebola. Regeneron Pharmaceuticals Inc., which developed a successful Ebola antibody treatment, is also working on a coronavirus antibody "cocktail" and says human trials could begin by early summer. But any such drug would have to be injected, which would likely require it to be refrigerated and administered by doctors—all of which would limit its use. It's not the ideal. But it's what might be good enough as a start.
In January, Chavez and Debbie Hong, one of the doctoral students working in his lab, were reading about the coronavirus like everyone else. When its genome was posted on a public-health website, they downloaded the sequence, found the protease gene, and paid a bioscience company about $80 to synthesize it.
One of the problems with screening drugs against more than one viral protease at a time is that it's hard to tell which drugs are blocking which proteases.
Chavez solved this problem by putting proteases from each virus into different cells, then creating what he calls nametags for each of the cells. He adds possible drug compounds to the cells and uses genome sequencing to read the tags, which allows him to see whether any of the viral proteases are blocked by each drug.
It might take three to six months for Chavez to detect a few lead compounds that efficiently block coronavirus proteases. If—when—he does, Ho will connect him to chemists who will, over a matter of a few more months, increase the potency of the compounds by 100%, maybe 1,000%. "We know that kind of gain is doable," Ho says. It would be an important but still early step in creating a drug that would stop not only one viral protease but proteases from many coronaviruses. Because now we all know they're out there.
----------------------------------
The Tip of the Iceberg: Virologist David Ho (BS '74) Speaks About COVID-19
March 20, 2020
As of March 20, more than 8,700 people worldwide had died of COVID-19, the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Caltech trustee David Ho (BS '74) of the Aaron Diamond AIDS Research Center, Columbia University, says that this is just the tip of the iceberg. Ho, an expert on viral epidemics, has spent decades researching HIV/AIDS, having begun his career in Los Angeles, "ground zero" of the first outbreak, in the early 1980s. On March 18, Ho sat down with members of the Caltech community to discuss the novel coronavirus and the future of our society in the light of this global pandemic.
Let me just give you a picture of what I see here in New York. About two weeks ago, we had our initial case, and now in New York City newly diagnosed confirmed cases are tripling every two days. In our New York Presbyterian Hospital, approximately 25 percent of the swab samples that are submitted for testing are positive. In the suburban communities outside of New York, approximately 10 percent of the swabs submitted are positive. So, the virus is everywhere. And in New York, we know that we are in the exponential growth phase of the epidemic.
I personally believe we will blunt this epidemic, but I think we wasted a good four to six weeks largely because of lack of testing and lack of a certain preparedness. But I think we could still make a difference and bring it under control with very harsh measures.
But again, are these measures sustainable? We've got to expect that businesses must reopen and schools must teach again. Whether it's travel or sports or live entertainment, we're going to have to return to some semblance of normalcy. But what are the measures that are effective and sustainable? That's a question we as a society have to deal with. We need to buy time so that gradually the population will have a degree of immunity.
Most importantly, we need to buy time to allow science to deliver solutions. We're going to have to develop drugs, antibodies, and vaccines. I think the mobilization by the scientific community, from my perspective, is amazing.
Back https://www.caltech.edu/about/news/tip-iceberg-virologist-david-ho-bs-74-speaks-about-covid-19
Can you tell us about the pathology of the disease?
COVID-19 typically causes fever and a dry cough. One may have aches in the body—the muscles—and if it's severe enough, there would be shortness of breath due to pneumonia.
Gastrointestinal symptoms can occur and are an indication of more severe disease. It's not very common to have a runny nose or the sniffles, and a sore throat is not common either.
The incubation period from exposure to onset of symptoms is between four and six days; and if you want to cover 95-98 percent of the cases it is between three and 10 days. It's pretty rare to have an incubation period outside of that range.
What in particular makes this virus so dangerous?
What is disturbing is that virus shedding, as detected in the mouth or nose, is very, very common and could be there prior to onset of symptoms. That's why transmission could occur from asymptomatic individuals. And virus shedding could continue for days up to three weeks after a person recovers. That is extremely worrisome for the spread of this virus. Furthermore, the stability of this virus is worrisome as well. If you put it in aerosol form and keep it in the air, the half-life is several hours; if you drop it on surfaces of copper or cardboard, it could survive about a day. But if it's on steel or plastic surfaces, you could still detect infectious virus after 72 hours, although the infectivity decreases with time.
|
|
| |
| |
|
|
|
