COVID-19 antibodies: Race to 'uncrown' the coronavirus
World Insight with Tian Wei
As COVID-19 leaps from one grim milestone to another, one scientist offers a ray of hope. David Ho is the director and CEO of the Aaron Diamond AIDS Research Center at Columbia University and one of the preeminent experts on HIV research in the world. CGTN Host Tian Wei spoke to him on his latest breakthrough regarding COVID-19 antibodies.
Last week, Ho's team discovered a collection of monoclonal antibodies that could bind to the outer spike of the coronavirus. "These antibodies are exclusively potent in killing this virus, and these antibodies also attack three different areas on the spike of the virus," said Ho.
Ho elaborates on the importance of the coronavirus' "spike" from which it derives its crown-related name.
"The spike is what the virus uses to bind and enter the cell. Prior to our research, antibodies were only directed to one region of the spike to neutralize the virus by blocking its engagement of the cell receptor. But we thought that there were several other regions along the spike that antibodies could target and inactivate the virus."
Ho explains how his team came to identify these game-changing antibodies. "We first isolated them from five different infected patients. We selected these patients because their blood contained particularly strong antibodies against COVID-19. So we isolated their blood cells that were responsible for making antibodies. These are known as B cells. We target these B cells that could recognize the spike, and we cloned them."
After sequencing these antibody genes they were able to obtain over 250 monoclonal antibodies from the five patients.
"Among those 250 monoclonal antibodies. Half of them turned out to be specific to the spike. And a quarter of them were capable of neutralizing the virus. And among those nine were exclusively potent which means they can kill the virus at extremely low concentrations."
These antibodies will now be taken forward as agents to treat and prevent COVID-19 infections. Ho hopes that in the next couple of months the best candidates can be forwarded for clinical use. These antibodies can either prevent existing patients progressing to a severe state or be administered to healthy people as a "passive vaccine."
It is a race against the clock in producing antibodies as mutations could render antibodies ineffective. "Viruses can mutate and escape from drugs and antibodies," said Ho. He mitigates this risk by advocating a two-antibody cocktail. "A two antibody cocktail, unlike a single entity, will help prevent the virus from escaping." To this end Ho has also tracked the progression of the various COVID-19 strains. "The strain first detected in Europe now accounts for 70 percent of new worldwide infections. But all these divergent strains are equally susceptible to the killing by the antibodies."
Ho, whose AIDS research made him the first doctor named Time magazine's Man of the Year in 1996, is well versed to tackle the coronavirus.
"There are many lessons from the HIV field that can be applied to COVID-19 research. Viruses have the propensity to mutate and escape from drugs. HIV has a high mutation rate. The mutation rate of COVID-19 is not as great as HIV, and doesn't replicate for as long as HIV. So it's easier to address than HIV."
The need for speed in antibody research is intensified by Ho's prediction. "The virus is worse than ever in Brazil and South America. Pretty soon the Northern Hemisphere will be facing cooler weather which will favor the virus even more. We need to get this pandemic under control otherwise carnage will follow." This timeline is unfavorable for the slow process to produce vaccines.
"We are moving into late stage studies for efficacy of vaccines. But it's going to take time. We need 20,000 subjects to assess efficacy. We don't know whether vaccine responses will be durable; whether they will be sufficiently robust; whether there will be rare complications until enough people have been vaccinated and there has been enough follow-up. There are so many things to be cautious about even if the early trials prove to be effective."
Regardless of whether antibodies or vaccines hit the market first, Ho asserts, "You won't have economic health until you have good public health."
World Insight with Tian Wei is an international platform for debate and intelligent discussion. It is the meeting point of both the highly influential and rising voices, facilitated by host Tian Wei. It provides nutrition to form your own thoughts and ideas through a 45-minute live debate and interviews.
Time (GMT): 1415, 2015
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