Coronavirus: deployment of antibody tests has encountered confusion and little surveillance


While the Centers for Disease Control and Prevention launched a strategy to use antibody tests for surveys that study the spread of the virus in different locations and populations, the federal government has not coordinated an effort to track the raw data antibody tests done in all states.

Antibody tests can be used to detect if people have already been exposed to and have developed antibodies to the coronavirus, although it is still not clear whether the presence of antibodies means that a person is immune to the virus.

The current calculation of people who have been infected with a coronavirus in the United States – 1.25 million, according to a count by Johns Hopkins University – is almost certainly an undercoverage, said Dr. Peter Hotez, professor and dean from the National School of Tropical Medicine at Baylor College of Medicine.

“The problem is that we don’t know if that real number is 10 times more or 20 times more and having generalized antibody tests that would give us a better idea,” said Hotez.

Yet of the 41 states that responded to a CNN survey, only 22 states said they are currently tracking or collecting antibody test data in one way or another. Some of these states, including New York, Louisiana and California, are now requiring laboratories to report antibody test results, while others have launched limited surveys to study the prevalence of antibodies.

Scientists at the Mirimus, Inc. laboratory are working to validate rapid IgM / IgG antibody tests of COVID-19 samples from patients collected on April 10, 2020 in New York.

To further complicate matters, some state health departments have expressed concerns about the reliability of available antibody tests, many of which were originally placed on the market without being examined by the Food and Drug Administration.

Public health experts argue that due to a series of political and procedural decisions, public health experts have argued that how to approach antibody testing is one of the last barriers to the coronavirus response. US health system, which was initially lagging behind on tests to diagnose cases of coronavirus.

States concerned about the accuracy of antibody tests

Antibody test data “is of questionable reliability; we don’t track or analyze them, “said a spokesperson for the Oregon Health Authority.

A Vermont task force that has researched antibody testing for the state health commissioner “has found that the tests currently available are not precise or reliable enough to make decisions or recommendations aimed at to change individual behaviors or at the population level, “according to a spokesperson for the Vermont health operations center.

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At the federal level, the CDC has started using “seroprevalence surveys” to track the virus, which use blood tests to calculate the percentage of people who have antibodies to the virus at different times. These surveys can perform tests on blood samples that were originally taken for other purposes, such as routine cholesterol tests. ra

A spokesman for the CDC said the agency had no estimate of the number of antibody tests performed or information on all of the test results. But the spokesman also said the CDC is working with states that perform antibody tests as well as with some commercial companies to get the test results.

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The different approaches to antibody testing, also known as serological testing, follow a policy released by the Food and Drug Administration in March that allowed companies to sell the tests without providing evidence that they worked. The researchers argued that this policy, which aimed to promote rapid access to testing, had allowed inaccurate antibody tests to enter the market.

The FDA changed its policy on Monday to require commercial antibody test manufacturers to submit emergency use authorization, or EUA, and validation data within 10 business days.

Despite criticism of the agency’s initial policy, an FDA spokesperson told CNN: “Without the more flexible policy, we would not be as advanced in our ability to use antibody tests. Now that the FDA has authorized several tests and the National Cancer Institute, in collaboration with us and others, is conducting antibody test evaluations, we can and have changed our policy to require that all tests from commercial manufacturers be authorized by the FDA to stay or come to the US market. “

The FDA spokesman added that the agency has ongoing conversations with states to provide technical assistance.

Progress has been uneven

At least 12 serologic tests have already received the EUA and major medical device companies have increased production. Abbott Labs, for example, told CNN that it shipped approximately 5 million antibody tests to customers across the United States this week. Abbott says his antibody test is accurate and reliable.

FDA Commissioner Hahn tweeted last month, serological tests can play a vital role in the fight against the disease “by helping health professionals identify people who may have overcome # COVID19 and developed an immune response”.
How & # 39; the pivotal event & # 39; from Covid will change everything

Still, some state health officials say the current usefulness of antibody tests is limited.

Massachusetts state epidemiologist Dr. Catherine Brown told CNN that her state’s health department has started to receive test results for antibodies, but said the numbers were small and not sufficiently geographically distributed to draw conclusions about the prevalence of the infection.

Employees of the L.A. County Public Health Department perform antibody tests.

Aside from questions about the accuracy of tests that have not received FDA clearance, she said the correlation between the presence of antibodies and an individual’s immunity to the disease is not Claire. The World Health Organization said, “There is currently no evidence that people who have recovered from Covid-19 and who have antibodies are protected from a second infection. “

Brown also said that knowledge about the time of development and the duration of different types of antibodies is limited compared to when a person was infected.

“At the moment, aside from using serological testing to find out how many people in a community have been exposed to the virus, it should be used sparingly and with a solid understanding of its limitations,” said Brown.

Experts advise against drawing conclusions from published data

Some states have released data on antibody tests.

The Arizona Department of Health Services, for example, reports that 14,652 serological tests have been performed, with a positive rate of 3.7%. Although the department also notes, “it is difficult at this time to draw conclusions” from the data and warns “an antibody test may be false positive for Covid-19 because the test may have detected the presence of antibodies to other cold-causing coronaviruses. “

Other states, including Alabama, Idaho and Utah, have told CNN that they receive antibody test results or information but have not yet implemented processes to analyze data.

Kelly Wroblewski, director of infectious disease for the Association of Public Health Laboratories, which represents local and national public health labs, told CNN that she had heard from epidemiologists in the states currently collecting this data from various laboratories that do not know what to do with the data due to the varying quality of different tests.

“You will not necessarily get reliable prevalence data if you are just crowdsourcing from laboratories that might use good or bad tests,” said Wroblewski.

To bring clarity to the situation, Wroblewski APHL’s organization and the State Council and territorial epidemiologists released a policy document on antibody testing on Thursday.

The document says that scientists need more data on test performance and the human immune response to the coronavirus for antibody testing methods to be used effectively, but also that public health officials can use drug tests. antibodies to conduct surveys to estimate the prevalence of past infections. Another potential application listed is to identify people with antibodies to serve as plasma donors for patients with coronavirus.

Rhode Island Governor Gina Raimondo announced Wednesday that 5,000 residents of his state will be randomly selected to receive tests to diagnose the virus as well as antibody tests for Covid-19 so the state can have a more precise portrait of the number of people exposed to the virus.

New York City, in partnership with the Department of Health and Human Services and the CDC, will offer antibody tests to 140,000 health care workers and first responders starting next week, the mayor said on Tuesday Bill de Blasio.

Trump’s “Blueprint Test” leaves states alone

The Trump administration’s Testing Blueprint for the reopening of the country underscored the importance of antibody testing, particularly among critical groups such as first responders and vulnerable populations. But the document called on states to develop their own individual test plans.

Senate Democrats, in a letter to President Trump on Tuesday, criticized what they called “the lack of detail and strategy” in the plan. They called on the administration to develop specific plans to implement antibody screening programs.

Heather Pierce, senior director of science policy and regulatory counsel at the Association of American Medical Colleges, said she was not surprised that states have developed different approaches to antibody testing.

“States have been asked to make their own plans, and there are no strict testing guidelines, let alone serologic testing,” said Pierce.

Pierce said states should recognize the limits of antibody testing but start creating databases that track the results of antibody tests and the types of tests used, so that when more information becomes available on the relationship between anti-coronavirus antibodies and immunity, states have this data ready.

“It’s about ensuring that states collect the information that will ultimately be useful,” said Pierce, who added that states should ideally use “the same vocabulary” in their data sets, so that they can compare them.

Caroline Buckee, Associate Professor of Epidemiology at Harvard TH Chan’s School of Public Health, said that knowing more about people with the virus would reveal more about “where we are on the epidemic curve” .

“And this has very important policy implications, such as if we are going to go back to work and if we are going to reopen schools,” said Buckee.


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