New US test could detect virus before patients become infectious
Defense Department working on new blood-based screening that identifies body’s immune response, may find illness 4 days earlier than current swab tests
The US Defense Department, working with civilian research teams, is currently developing a new coronavirus test that could detect the illness earlier and with more accuracy, potentially allowing the isolation of patients before they become infectious, according to a new report.
Scientists with the Defense Advanced Research Projects Agency (DARPA) told the Guardian Friday that they hope the new test, based on blood samples, will be able to identify carriers 24 hours after they are infected — some four days before current testing can.
The virus is believed capable of incubating for several days and to take up to two weeks before symptoms first appear.
While current tests, based on nose swabs, can only detect the virus once it has proliferated through the body and is present in the nasal cavity — approximately five days after infection — blood tests would be based on the immune system’s response, which is detectable far earlier, before the virus becomes transmittable.
They are also believed to be more accurate, researchers told the paper, as there is far less room for error than with swabs, where incorrect sampling practices can lead to false negatives.
“We are all extremely excited,” DARPA’s Dr. Eric Van Gieson said. “We want to roll this test out as quickly as we can, but at the same time share with others who might want to implement in their own countries.”
If given FDA approval, researchers hope to start using the tests in the US in some two weeks.
They caution that they will not be able to gather sufficient data on the tests efficacy before mass use begins, but note that with other viruses detection using blood testing occurs some 24 hours after infection.
DARPA’s Dr. Brad Ringeisen said the test could be “a game changer” in fighting the global pandemic.
Van Gieson also noted that labs will need to make very little adjustments to analyze tests, as they use the same thermal cyclers (or PCR machines) currently being used for nose swab samples. “The infrastructure is already there,” he said.
A possible downside is blood sampling being less convenient than the current model of testing, which in some setups allows people to be tested without leaving their cars. Notably, however, very little blood is required for the test — only one milliliter, about a fifth of a teaspoon.
Effective testing and isolation of carriers is seen as critical in allowing the world to release lockdown restrictions on the global population and return to normal life.
Also on Friday US regulators allowed emergency use of an experimental drug that appears to help some coronavirus patients recover faster.
Remdesivir is the first drug shown to help fight COVID-19, which has killed more than 237,000 people worldwide.
The FDA said in a statement that Gilead Sciences’s intravenous drug would be specifically indicated for hospitalized patients with “severe disease,” such as those experiencing breathing problems requiring supplemental oxygen or ventilators.
US President Donald Trump announced the news at the White House alongside Gilead CEO Daniel O’Day and Food and Drug Administration Commissioner Stephen Hahn.
“This was lightning speed in terms of getting something approved” said Hahn, calling the drug “an important clinical advance.”
The FDA acted after preliminary results from a government-sponsored study showed that the drug, remdesivir, shortened the time to recovery by 31 percent, or about four days on average, for hospitalized COVID-19 patients.
The study of 1,063 patients is the largest and most strict test of the drug and included a comparison group that received just usual care so remdesivir’s effects could be rigorously evaluated.
Those given the drug were able to leave the hospital in 11 days on average vs. 15 days for the comparison group.
The FDA said that performance warranted Friday’s decision, though regulators acknowledged “there is limited information known about the safety and effectiveness of using remdesivir.”
The drug’s side effects include potential inflammation of the liver and problems related to its infusion, which could lead to nausea, vomiting, sweating and low blood pressure. Information about dosing and potential safety issues will be provided to physicians and patients, the FDA said.
The National Institutes of Health’s Dr. Anthony Fauci said Wednesday the drug would become a new standard of care for severely ill COVID-19 patients. The drug, which blocks an enzyme the virus uses to copy its genetic material, has not been tested on people with milder illness.
The FDA authorized the drug under its emergency powers to quickly speed experimental drugs, tests and other medical products to patients during public health crises.
Gilead Sciences has said it would donate its currently available stock of the drug and is ramping up production to make more. It said the US government would coordinate distribution of remdesivir to places most in need of it.
The FDA previously allowed narrow use of a malaria drug, hydroxychloroquine, for hospitalized patients who were unable to take part in ongoing studies of the medication. Trump repeatedly promoted it as a possible COVID-19 treatment, but no large high-quality studies have shown the drug works for that and it has significant safety concerns.
The FDA warned doctors late last month against prescribing the drug outside of hospital or research settings, due to risks of sometimes fatal heart side effects.
Two small studies published Friday have added to concerns about the malaria drug. Critically ill COVID-19 patients given hydroxychloroquine were prone to heart rhythm problems, and for many risks mounted when it was combined with an antibiotic, the studies found.