Name: Rare, super coronavirus antibodies likely to yield vaccine, say Stanford, UCSF experts
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Rare, super coronavirus antibodies likely to yield vaccine, say Stanford, UCSF experts

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This is a carousel. Use Next and Previous buttons to navigateThe discovery of antibodies that block the most infectious elements of the coronavirus is helping Bay Area scientists unlock the many mysteries of human immunity, and could be crucial in the development of a vaccine.Epidemiologists have found “neutralizing antibodies” in fewer than 5% of COVID-19 patients, but the ones they are now attempting to isolate are unique in their ability to prevent SARS-CoV-2 — the specific coronavirus that causes the illness — from entering human cells.It means anyone with these antibodies would almost certainly be immune to the disease and that their could potentially be used to inoculate others, according to several by research laboratories in the United States and China.Dr. George Rutherford, a UCSF infectious disease specialist, said neutralizing antibodies attack the virus’ crown-like spikes, which are the genesis of the name “corona,” preventing them from poking into and hijacking human cells.This particular antibody prevents “the key from going into the lock,” Rutherford said, referring to the spike proteins, which must latch onto a human cell before the parasitic virus can replicate itself. “That’s what you want if you are going to have immunity.”The super-strength antibody is one of many discoveries over the past three months by scientists in laboratories, hospitals and universities . One thing that’s clear from the research is how is. Researchers say, for instance, that while some infected people develop killer antibodies, others have no antibodies at all.Between 10% and 20% of patients with COVID-19 show no antibodies in serological tests, Rutherford said. The remaining 75% or more of coronavirus patients develop antibodies, he said, but they aren’t the neutralizing kind, indicating immunity to the disease might not last long in most people.“The way I think about it, we have a certain amount of the population that, even if they have a history of infection, won’t have any measurable antibodies and therefore won’t have immunity,” Rutherford said. “Then there is a certain proportion who will have high levels of antibodies and some who have transient antibodies, where we don’t know how long those antibodies will last.”Antibody tests, also called serological tests, can determine whether someone had the disease — even if the person never had symptoms. The antibodies researchers are looking for generally show up 11 or 12 days after infection and, although nobody knows exactly how long they remain in the body, they persist for quite awhile and are easily measured. Researchers have found that as people get better, their antibody levels rise. It is believed that repeated exposure to the virus may actually boost the antibody response.Coronavirus PandemicThe problem is, nobody knows yet whether someone with antibodies is protected from getting sick again. To date, there have been no verified cases of reinfection, so it appears there is some immunity in people who have gotten sick. But researchers want to know how long that resistance lasts.When they are detected, neutralizing antibodies are generally found in low concentrations. So epidemiologists must figure out how to increase their numbers, create an effective serum and safely immunize people with it.“We are still trying to learn more about the nature of neutralizing antibodies,” said Dr. Yvonne Maldonado, chief of infectious diseases in the Department of Pediatrics at the Stanford University School of Medicine, who is using blood plasma from infected individuals to see if she can artificially inactivate the virus. “We still need to determine how much do you need, how long does it last (and) does it protect you from infection.”Her team of researchers is trying to identify the specific white blood cells, known as B cells, that secrete the neutralizing antibodies. The plan is to clone the B cells, mass produce the antibodies and give them to people in trials to see if they reduce infection.Another unknown, Maldonado said, is whether people who are infected but have no symptoms can still infect other people.“We now know that between a third and four-fifths (of infected people) are asymptomatic entirely, meaning not only do they not get symptoms, but they don’t even know they got infected,” said Eran Bendavid, a Stanford population health and disease modeling expert who conducted a study indicating that as many as with the virus than the number of cases reported.The use of serological tests to calculate the number of unreported infections has been controversial, in part because of a high percentage of inaccurate results, and Bendavid’s calculations were challenged by many infectious disease specialists. But tests in other regions have come up with a of infection rates, including some much higher than his model.And there have been troubling reports ofeven in asymptomatic individuals, including fevers and heart inflammation in children more than a month after apparent exposure to the virus.Updated to include drought zones while tracking water shortage status of your area, plus reservoir levels and a list of restrictions for the Bay Area’s largest water districts.Doctors at UCSF’s Benioff Children’s Hospital recently saw dozens of children with reddish-purple known as acral perniosis that appeared weeks or months after exposure to adult relatives with flu-like symptoms, leading researchers to believe it is an inflammatory reaction to the coronavirus.Studies of other viruses offer clues about the likelihood of developing immunity to COVID-19.People who contract measles, for instance, develop lifelong immunity. But with other diseases, like mumps, immunity wears off over time. People can get influenza every year mainly because the virus mutates often, creating an infinite number of variations that can each cause a person to get sick.Coronaviruses, which mutate only once or twice a month, are unpredictable in. Studies of four seasonal coronaviruses that cause the common cold show that people develop antibodies, but the levels appear to decline slowly over time and people eventually become susceptible again.The immune response may be stronger for lower respiratory viruses, like COVID-19. People sickened by the developed immune responses that have lasted.International researchers recently found that some rhesus macaques infected with the coronavirus developed neutralizing antibodies and could not be reinfected after they recovered.Most virologists say it will be difficult to develop a safe and effective coronavirus vaccine by January 2021, the date the Trump administration has laid out in what it calls Operation Warp Speed. It normally takes about a decade to develop vaccines. The fastest ever was four years for the mumps vaccine, which was licensed in 1967.Butsay they have the building block they need to move forward.“To make a vaccine you need to have neutralizing antibodies,” Maldonado said. “We don’t know if it makes them immune for life, but we know people are capable of producing them. That’s good news, but now we need to understand what that means.”Peter Fimrite is a San Francisco Chronicle staff writer. Email: Twitter:Updated to include drought zones while tracking water shortage status of your area, plus reservoir levels and a list of restrictions for the Bay Area’s largest water districts.

This is a carousel. Use Next and Previous buttons to navigateThe discovery of antibodies that block the most infectious elements of the coronavirus is helping Bay Area scientists unlock the many mysteries of human immunity, and could be crucial in the development of a vaccine.Epidemiologists have found “neutralizing antibodies” in fewer than 5% of COVID-19 patients, but the ones they are now attempting to isolate are unique in their ability to prevent SARS-CoV-2 — the specific coronavirus that causes the illness — from entering human cells.It means anyone with these antibodies would almost...

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Rare, super coronavirus antibodies likely to yield vaccine, say Stanford, UCSF experts

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