[ad_1]
A worker collects a sample for a Covid-19 antibody test in Los Angeles, August 5.
Photographer: Patrick T. Fallon / Bloomberg
Photographer: Patrick T. Fallon / Bloomberg
We are tracking the latest information on the coronavirus outbreak and the global response. Sign up for our daily newsletter here on what you need to know.
A new crop of Covid-19 antibody tests measures the level of protection someone has accumulated against the deadly virus and can help determine which vaccines are most effective.
Siemens Healthineers AG is the first large company to obtain approval from the United States Food and Drug Administration for a test measuring the concentration of long-lasting antibodies circulating in a person’s blood. Swiss giant Roche Holding AG continues with its own version.
Antibodies are markers of infection, and testing them helps health officials see how far the virus has spread. So far, most tests could only tell if they were present. The most recent go even further by measuring the amount of these proteins, which are increased by the immune system to deactivate viral invaders.
The different Covid-19 tests and what they can reveal: QuickTake
The level of the body’s response is important in determining whether patients will develop immunity. Determining the effectiveness of vaccines is also critical, as developers introduce promising candidates into late stage trials.
“You need a test that shows whether a vaccine has triggered the right level of antibodies in a patient’s blood,” said Deepak Nath, president of laboratory diagnostics at Healthineers. “It’s important to say how many you have.”
Vaccine trials
Moderna Inc. used a form of quantitative testing to show that all 45 participants in a Phase I trial of its investigational coronavirus vaccine have developed antibodies. Of the society The Phase III trial, however, is considerably larger – with around 30,000 people. And it is only a candidate on a domain of more than 160 different plans in development around the world.
Taken as a whole, this vaccine research boom could create a huge demand for quantitative antibody testing – and this need could increase once vaccines are actually approved, as authorities will have to monitor their performance as billions people could be vaccinated. The big diagnostic companies say they are ready.
“We have talked to many vaccine companies and they are very interested,” Thomas Schinecker, The head of diagnostics at Roche Holding AG, said on a call with reporters last month. Roche is in the final stages of development of its quantitative test and plans to share more information in the coming months, the company said.
It has been a long and bumpy road for Covid-19 antibody testing. At first, the main goal of test makers was to introduce a tool that could simply detect whether a person’s immune system has fought off the coronavirus, to supplement other tests that show if they are currently infected.
Viral spread
Design a device to answer this question turned out to be quite difficult, with many countries stock up on tests that have proven to be unreliable. Eventually, big players such as Siemens Healthineers, Roche and Abbott Laboratories produced reliable diagnostics to better understand the spread of the virus.
Officials used these tests to estimate that about a quarter of New Yorkers had been infected in April, while about 7.1% of people in the UK was in July.
So far, antibody tests have generally been sought for evidence for a range of antibody types, including those that usually appear quickly but short-lived and another type that appears later but offers protection. longer.
Healthineers’ new test focuses on the latter. Once an organization like the The International Federation of Clinical Chemistry and Laboratory Medicine is determining what level of these antibodies is needed to confer immunity, researchers can see who needs a vaccine, a booster, or nothing at all.
Antibodies are not the body’s only defense. T cells can kill cells infected with the virus, while memory cells persist for years, ready to repopulate the body with both weapons if the virus returns. Yet antibodies are the easiest to measure, making new quantitative tests a potentially powerful way to better understand the full response of the immune system.
“What does the antibody mean in relation to, say, the T cell-mediated response?” Nath said. “From a research point of view, it is the first tool of its kind to be able to carry out these studies.”
Spike protein
Roche has another reason for proposing a quantitative device. The first antibody test he introduced in May detects the presence of antibodies targeting the nucleocapsid that surrounds the nucleic acids of the coronavirus.
However, research has shown that the most protective antibodies are those that target the spike protein that allows the virus to enter cells. Most vaccine developers offer injections that induce the body to make antibodies bound to spike proteins, which could potentially weaken demand for Roche’s core product.
Roche’s quantitative test focuses on advanced anti-protein antibodies. The company will then be able to use its two antibody tests together, a potential benefit as a small percentage of people develop antibodies against the peak or the core, not both. “You’ll get a better understanding of what’s going on there if you do a combination of the two,” Schinecker said.
Quantitative antibody testing could also help with treatments involving convalescent plasma, in which people who have already defeated Covid-19 donate their blood rich in antibodies to those who are still fighting the virus.
“If five people come to a clinic, you can take blood and say, ‘Hey, this person has more antibodies than this other person and so maybe a better candidate for a blood donation,’” he said. declared Nath.
[ad_2]
Source link