Tag Archives: antibody test

Good news for a change. Coronavirus Antibody Testing Shows Lower Fatality Rate For Infection : Shots – Health News : NPR


Tests for the immune response to the coronavirus are revealing thousands of people who were infected but never got severely ill. The findings suggest the virus is less deadly than it first appeared.

Full story of excerpts below at Source: >Coronavirus Antibody Testing Shows Lower Fatality Rate For Infection : Shots – Health News : NPR

Mounting evidence suggests the coronavirus is more common and less deadly than it first appeared. The evidence comes from tests that detect antibodies to the coronavirus in a person’s blood rather than the virus itself.

The tests are finding large numbers of people in the U.S. who were infected but never became seriously ill. And when these mild infections are included in coronavirus statistics, the virus appears less dangerous. …But even a virus with a fatality rate less than 1% presents a formidable threat.

“That is many times more deadly than seasonal influenza,” ….Studies suggest a healthy young person’s chance of dying from an infection is less than 1 in 1,000. But for someone in poor health in their 90s, it can be greater than 1 in 10...And that means different states in the U.S. should expect different infection fatality rates.

 

Antibody Testing Is Increasing, But A Positive Result Doesn’t Prove Immunity : Shots – Health News : NPR


As more and more people get tested for antibodies to the coronavirus, infectious disease specialists worry that those tested — and their employers — may not understand the limits of the results.

>Google search on this topic, last month: 

5 minute podcast and read full story at Source: >Antibody Testing Is Increasing, But A Positive Result Doesn’t Prove Immunity : Shots – Health News : NPR

“It’s still not certain that antibodies measured by such a test would protect him from catching the virus again. And if the antibodies are protective, it’s unknown how strong that protection might be or how long it might last. There are also questions about the reliability of many antibody tests being sold.

“Researchers are urgently trying to answer those uncertainties and figure how best to conduct antibody testing. Nevertheless, increasing numbers of people are getting the tests — many without recognizing how much is still unknown about what the results mean.

“the antibody tests are only a sign of past infection. Whether the infection is actually gone can only be determined by a diagnostic test that identifies genetic material from the virus or viral particles. Some people also falsely think testing positive on an antibody test proves they can’t get infected with the virus again.

Read full story at Source: >Antibody Testing Is Increasing, But A Positive Result Doesn’t Prove Immunity : Shots – Health News : NPR

Antibody, Antigen And PCR Tests For COVID-19: Know The Differences : Shots – Health News : NPR


>Google News Full Coverage

>Update: FDA Cracks Down On Antibody Tests For Coronavirus

“Testing for the coronavirus has been very much in the news. The first and most urgent focus is on increasing access to tests to diagnose people with current infections. But now other tests are appearing as well. Antibody tests, which can identify people with signs of past infection, are starting to be available. And a third type of test is on the way.

“Here’s a quick guide to sorting out the pluses and minuses to each type of test:

“Diagnostic or PCR test. What it does: Doctors use this test to diagnose people who are currently sick with COVID-19. This is the one we’ve been hearing so much about. How it works: This test uses a sample of mucus typically taken from a person’s nose or throat. The test may also work on saliva — that’s under investigation. It looks for the genetic material of the coronavirus. The test uses a technology called PCR (polymerase chain reaction), which greatly amplifies the viral genetic material if it is present. That material is detectable when a person is actively infected.

” How accurate is it: Generally speaking, these are the most reliable tests. However, a few days may pass before the virus starts replicating in the throat and nose, so the test won’t identify someone who has recently been infected. And swabs can sometimes fail to pick up signs of active infection. How quick is it: These samples are generally sent to centralized labs for analysis, so it can take several days to get results back. Wait times were longer earlier in the pandemic because of a testing backlog. There are also two rapid PCR tests, which can be run on specialized equipment already widely distributed throughout the U.S. The speediest one, by Abbott Laboratories, can provide a result in 13 minutes, but one study suggests this test can miss more than 10% of cases.

“Antibody test. What it does: Antibody tests identify people who have previously been infected with the coronavirus. They do not show whether a person is currently infected. This is primarily a good way to track the spread of the coronavirus through a population. How it works: This is a blood test. It looks for antibodies to the coronavirus. Your body produces antibodies in response to an infectious agent such as a virus. These antibodies generally arise after four days to more than a week after infection, so they are not used to diagnose current disease.

“How accurate is it: There are more than 120 antibody tests on the market. The Food and Drug Administration has allowed them to be marketed without FDA authorization, and quality is a great concern. A few tests have voluntarily submitted to extra FDA approval. Other tests are being validated by individual medical labs or university researchers. In general, these tests aren’t reliable enough for individuals to act based on the results. And researchers say, even if you were certain you had antibodies to the coronavirus, it’s still unknown if that protects you from getting sick again. Still, these tests can provide good information about rates of infection in a community, where errors in an individual result have less impact. How quick is it: These tests generally produce results in a few minutes, based on a drop of blood taken from the finger. Some research labs use a more sophisticated antibody test, called an Elisa (Enzyme-linked immunoassay) that are more accurate but are not as widely available.

Continue reading more and third type of test not available yet at Source: >Antibody, Antigen And PCR Tests For COVID-19: Know The Differences : Shots – Health News : NPR

WHO: ‘No Evidence’ COVID-19 Antibodies Stop Re-infection | Time


(Reference links in Video are accessed by clicking “Youtube” button. They will be listed under video on Youtube.)

>Access WHO report

“Catching COVID-19 once may not protect you from getting it again, according to the World Health Organization, a finding that could jeopardize efforts to allow people to return to work after recovering from the virus. “There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection,” the United Nations agency said in an April 24 statement.

“The WHO guidance came after some governments suggested that people who have antibodies to the coronavirus could be issued an “immunity passport” or “risk-free certificate” that would allow them to travel or return to work, based on the assumption that they were safe from re-infection, according to the statement. People issued such a certificate could ignore public-health guidance, increasing the risk of the disease spreading further.

“Chile was the first country to announce plans to issue immunity cards based partly on antibody tests. This has raised concerns because the tests have proven unreliable elsewhere, and some people may get deliberately ill in order to obtain the card.

“The U.S. and others have nonetheless said they’re looking into the option. While there’s a consensus that the key to ending the coronavirus pandemic is establishing co-called herd immunity, there are many unknowns. One is whether researchers can develop a safe and effective vaccine. Another is how long people who’ve recovered have immunity; reinfection after months or years is common with other human coronaviruses.

“Finally, it’s not clear what percentage of people must be immune to protect the “herd.” That depends on the contagiousness of the virus. The WHO said it’s reviewing the scientific evidence on antibody responses to coronavirus, but as yet no study has evaluated whether the presence of antibodies “confers immunity to subsequent infection by this virus in humans.” And while many countries are currently testing for antibodies, these studies aren’t designed to determine whether people recovered from the disease acquire immunity, the agency said.

Read full story at Source: >WHO: ‘No Evidence’ COVID-19 Antibodies Stop Re-infection | Time