Covid-19 antibody test still very unreliable says UCT infectious diseases prof
Across the globe, many people are anxious to learn whether they may have been infected with the coronavirus in the past – with the hope that it would offer some immunity in the future.
WIth Covid-19 tests being limited is antibody testing the way to go?
Lester Kiewit chats to Professor of Infectious Diseases at UCT, Marc Mendelson about the usefulness of antibody testing.
It warrants further discussion and warrants education about the place of antibody tests and whether they may be of benefit or not.Professor Marc Mendelson, Infectious Diseases - UCT
He says it is important to distinguish between these antibody tests, often called rapid tests, and the Covid-19 test conducted with a nose swab called a PCR test.
The PCR test detects the presence of the virus in a person and can be found a few days before they become symptomatic or will be present when they are already ill, he explains.
In contrast, an antibody is a protein that humans produce as an immune response against the virus.
In contrast to the PCR, antibodies take time to be produced and only appear in the blood in any reliable way about 10 to 14 days after the symptoms start.Professor Marc Mendelson, Infectious Diseases - UCT
This occurs once the virus has already been shed from the airways, he says.
It does not tell us much about the infectiousness of the person but tells us if the person has had the coronavirus previously. It does not help us with the acute diagnosis in terms of the tests that we have at the present time.Professor Marc Mendelson, Infectious Diseases - UCT
Would knowing one's status, whether one has had the infection or not, be helpful asks Kiewit?
Mendelson says there are a number of problems with this. He says the SARS-CoV-2 antibody test is not the same as, for example, an HIV antibody test which is a far more reliable marker.
He says the Covid-19 antibody tests are far less reliable. Even if one does have antibodies in the blood if the test is positive, it is uncertain whether that means one is immune from reinfection, he says. And that is also largely influenced by the different kinds of antibody tests available at present.
Unfortunately, at the current time with what we know at the moment, and we definitely need more studies, we can't say that having an antibody test even if it is positive can give that much peace of mind at the present time.Professor Marc Mendelson, Infectious Diseases - UCT
Listen to the interview below:
It’s possible that all the games will take place in Nelspruit, says IOL sports editor John Goliath.Read More
"Covid-19 is going to be with us for years. On balance, it’s better for kids to be in school," says Prof Mignon McCulloch.Read More
Health Minister Zweli Mkhize has warned of a second wave of Covid-19 if South Africans don't change their behaviour.Read More
"It’s not rational to allow packed taxis, but not a glass of wine in a controlled environment," says Francois Rossouw.Read More
The rise in infections coupled with misinformation about how the disease spreads, means some people are being harassed at work.Read More
The industry has been hard hit by the Covid-19 pandemic lockdown and it does not look like the end is in sight anytime soon.Read More
DA Finance Shadow Minister Geordin Hill-Lewis says both the DA and Cosatu warned govt as early as May that graft was inevitable.Read More
"If allowed to trade, we can’t be on the edge of our seats every time that the President is about to speak," pleads Kurt Moore.Read More
The bank is one of only six in the world to be recognised in this way for outstanding performance during the global health crisis.Read More
Breweries in SA can't sell beer but they can sell wort, a key part of the normal beer-making process. Here's how it works.Read More