New antibody tests could help develop more effective Covid vaccines
A new crop of Covid-19 antibody tests measures the level of protection someone has built up against the deadly virus and may help determine which vaccines are most effective.
Siemens Healthineers AG is the first big company to gain U.S. Food and Drug Administration clearance for a test that gauges the concentration of long-lasting antibodies flowing through a person’s blood. Swiss giant Roche Holding AG is following up with its own version.
Antibodies are markers of infection, and testing for them helps health officials see how widely the virus has spread. Until now, most tests could tell only whether they’re present. The newer ones go a step further, measuring the quantity of these proteins, which are raised by the immune system to disable viral invaders.
The level of the body’s response is important in determining whether patients will develop immunity. It’s also key to determining the effectiveness of vaccines as developers bring 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 much of it 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 experimental coronavirus vaccine developed antibodies. The company’s phase III trial, however, is considerably larger — with about 30,000 people. And that’s just one candidate out of a field of more than 160 different shots in development globally.
Taken together, this boom in vaccine research could create a huge demand for quantitative antibody testing — and that need could grow once vaccines actually win approval, since officials will need to monitor their performance as potentially billions of people receive shots. Big diagnostics companies say they’re ready.
“We’ve been talking to many of the vaccine companies and they’re very interested,” Thomas Schinecker, Roche Holding AG’s head of diagnostics, said on a call with reporters last month. Roche is in the final stages of development for its quantitative test and expects to share more information in coming months, the company said.
It’s been a long and bumpy road for Covid-19 antibody testing. Early on, the main objective of test makers was to introduce a tool that could simply detect whether someone’s immune system has fought off the coronavirus, to complement other tests that show whether they’re currently infected.