Answers to Questions About New Coronavirus Antibody Research | National / World News

NEW YORK — Studies are beginning to emerge to identify the number of Americans infected with the new coronavirus. But are they accurate?

Experts said the results depend on where and how the study is done, and it may be difficult to draw firm conclusions from early findings.

For example, a study in New York, the most infected country in the United States, estimates that the actual number of infections is about 10 times the official number. Research has shown that in Santa Clara County, California (including San Jose), infections are at least 50 times more likely. In Los Angeles County, scientists have increased the actual number of infections by about 40 times the actual number of cases.

Until recently, researchers have had to rely on statistical models. It was estimated that there were 7 to 10 infected but uncounted individuals in each confirmed case of coronavirus. With the advent of blood antibody testing, scientists want the situation to become clearer.

“ I think we’re starting to hear some interesting and interesting rays about the spread of infectious disease, ”said Stephen Morse, an expert on the spread of illness at Columbia University. I think it will be necessary.

Here is a guide to emerging research and some of the questions experts ask when reviewing them.

How do these studies work?

Researchers often take blood samples from a group of people, just a finger prick. They are not looking for active infections. They are testing antibodies, a marker of infection that someone already had.

It helps show how many people were infected, whether or not they knew. Studies such as these are widely used in public health to determine the number of people with various diseases such as measles, HIV, and dengue.

Why are these studies important?

Not all COVID-19s have undergone a diagnostic test. Diagnostic tests look for signs of active infection of the pharyngeal and nasal swabs. Therefore, blood tests can fill the gap.

If the blood tests are accurate and the study is well done, the study will help scientists determine what percentage of infected individuals did not have clear symptoms. You can also tell scientists how deadly the coronavirus is by finding the actual number of infections.

One day, research will help government officials understand the number of people who have acquired immunity to the virus. Such information can lead to decisions about when to cancel home orders.

Is the test accurate?

Dr. Jeffrey Engel, secretary-general of the State Council, a national body of disease investigators and territorial epidemiologists, said the first question to ask was which test was used.

According to a report released this week by researchers at Johns Hopkins University, there are dozens of blood tests for sale in the United States that are not completely accurate and incomparable to each other.

Even a small percentage of false positives can significantly distort our understanding of how many people are infected. False positives can even outnumber actual positives.

The Food and Drug Administration oversees the verification process to ensure that commercial testing is accurate. So far, government agencies have only approved four. Dozens of other tests are sold in the US without such permission.

Are the people tested representatives?

Generally speaking, the larger the research, the better.

“The more people can test both the current and the antibodies produced by the previous infection, the more accurately we can identify who is safe from the virus and who is infected with the virus,” said the United States. Dr. Albert Rizzo of the Lung Society said. Medical officer in a statement.

It is important to reach people of different ages, races, and different parts of the geographical area. Therefore, how to recruit participants is important.

Natalie Dean, a statistician and researcher at the University of Florida, says top-quality research involves going from home to home to adopt social cross-sections.

“In general, the first (investigation) is the easiest to do,” Dean said.

How were people gathered for early research?

In a study in Santa Clara County, California, a Facebook ad required most of the 3,300 participants to drive to a car park where they could get a finger stick or have a blood test.

Many experts blamed researchers for relying on volunteers, some of whom had previously been suspected of being infected. Various people may be excluded, such as those who are not on Facebook, those who do not have a car, or those who cannot join.

“Even if we have everyone, we still have the problem,” Dean said.

The Los Angeles study used a market research firm’s database to extract a more representative sample. However, the first results were less participants than the Santa Clara study.

A New York study collected about 3,000 samples from people shopping at grocery stores and large box stores. This is a preliminary survey by the government and more results are expected soon.

None of the studies have undergone the peer review process typically required before being published in a scientific journal.

What is ahead?

Two federal agencies are conducting larger studies.

The National Institutes of Health has published a study that recruits 10,000 adults nationwide to collect blood samples that were not previously diagnosed with coronavirus infections.

Several studies are planned at the CDC, one of which will eventually test nearly 20,000 blood samples collected in commercial laboratories. Dr Gregory Armstrong, deputy incident manager at CDC, said initial results could be coming back next month in some regions.

The CDC is also working on another study to test the remaining samples of previous blood donations, planning an additional study to be conducted in three or more US cities, he said.

“When things settle down in the country, we do more systematic things,” he said.

What else do scientists want to know?

Blood tests can help, but researchers need to know more than just the number of people who have antibodies.

For example, scientists need to determine the level of antibodies that protect someone from future illness from coronavirus and how long that immunity lasts. Also, people who are infected and asymptomatic may have to deal with the possibility that their antibody levels may be too low to be detected.

The Associated Press Health Sciences Department is supported by the Science Education Department of the Howard Hughes Medical Institute. AP is solely responsible for all content.