New test checks for antibodies, resistance to COVID-19

A lab technician tests blood samples for the presence of COVID-19 antibodies recently at a UT Health RGV testing site in Edinburg. A new test can tell if a mild COVID-19 infection may have powered up a person’s immune system with antibodies. COURTESY PHOTO

HARLINGEN — A new test can tell you if a mild COVID-19 infection may have powered up your immune system with antibodies.

The University of Texas Health RGV, the clinical arm of the UTRGV School of Medicine, has launched the COVID-19 antibody test at three locations in the Rio Grande Valley.

The now-familiar genetic test checks for acute infections with a rather painful swab deep into the nasal cavity. However, the antibody test consisting of a blood draw can determine if a past infection with little or no symptoms may have given you immunity, says Dr. John Thomas, UTRGV associate professor of biology.

“ What happens if you are somebody that perhaps got exposed to the virus two or three or four months ago when the pandemic was first taking shape and you didn’t get tested?” said Thomas, who is also director of COVID-19 operations at the UT Health RGV Clinical Lab.

“ Now you’re curious as to whether or not you were infected with the virus in the past,” Thomas said. “The antibody test will give you that answer.”

Thomas pointed out that about 80 percent of COVID-19 patients have little or no symptoms and may in fact be unaware they even had it.

“ They’re not going to have any symptoms or very few symptoms and they may have attributed their symptoms to COVID-19 or to allergies or just a cold,” he said.

Those are the lucky ones. Acute infections, on the other hand, can devastate the human body, causing patients to gasp for breath and suffer multi-system organ damage. Acute COVID-19 patients have a high incidence of stroke, heart attack and pulmonary embolism due to thickening of the blood. Thus, no one wants to risk contracting the disease, and this test can let them know if they’re in the clear.

“ If you think you were exposed six months ago, and you get tested today with the genetic test and it comes back negative, your employer may or may not accept that,” Thomas said. “One of the benefits of the antibody test is that it tells you if you’ve been exposed to this thing at all. Because once you get antibodies built up against an infectious agent, whether it’s a virus or a bacteria or something else, those antibodies generally hang around for the lifetime of the organism.”

There has been some discussion in various circles that antibodies don’t always last, that recovered COVID-19 patients can still test negative. Thomas attempted to clarify this.

“ That’s really not something that happens based on our understanding of the immune system,” he said. “What could be happening though is that, depending upon how much of an infection you have or have had when you were exposed to the virus, it’s possible that your body did not make a whole lot of antibodies.”

This brings into play the genetic variability of all species and individual differences in people’s immune systems.

“ Just as there are some people out there who are more or less prone to certain types of diseases like arthritis or lupus, the same thing is probably happening with COVID,” Thomas said.

“ And in the majority of people, we would expect to see that the antibody response would be durable and long lasting, but we’re not always going to be the same. So there probably have been a few people that have shown up and said, ‘Hey, I had antibodies six months ago and now they’ve kind of vanished or gone away.’”

However, in the vast majority of people, based on modern medicine’s understanding of the immune system, an organism will have a life-long antibody response to an infectious agent.

“ This is the principal behind vaccination,” Thomas said. “This is why we all get vaccines against measles and mumps and chicken pox when we’re babies.”

He cautioned, however, that some of what he’s saying about COVID-19 must be taken with a small grain of salt, as medical science has only studied the virus for a few months.

Consider the case of HIV which has been studied for almost 40 years and still the medical world doesn’t know everything about it. Study of COVID-19 will require many more years before a suitable accumulation of knowledge will become available.

However, Dr. Christopher Romero, internal medicine specialist at Valley Baptist Medical Center, has said that never before have so many scientists been involved in a global effort to understand a disease, and more will be learned in 18 months about this one virus than has ever been achieved.

Thomas said that, in spite of what is known about infectious agents and immune systems, there’s no guarantee the coronavirus will act the same way as other diseases.

“ There are always, especially in biology and infectious disease research, there’s always going to be an exception to the rule, just like there is in nearly everything else in life,” he said. “Based on our understanding right now, if you have antibodies against COVID-19, then yes you should be protected should you become exposed to the virus again.”

However, a disturbing caveat. This is an RNA virus, and as such it can mutate just like West Nile virus and dengue fever. Therefore, you might have been infected with one strain of the virus in December of last year, but in January of next year you could have a slight variation of COVID-19. Antibodies from last year’s infection may provide some immunity but not completely, meaning you could have a slight fever or a cough but not necessarily severe. Or it could be.

No one knows for sure yet, but Romero has said he’s cautiously optimistic a combination of vaccines, therapeutics and new safety measures could bring COVID-19 under control within the year. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said recently he believes some relief will come by the end of this year or early next year.

Anyone wishing to get the new antibody test should call 1-833-UTR-GVMD.

Draw/collection site locations:

• UT Health RGV Multispecialty, 2106 Treasure Hills Blvd., Harlingen 78550, (956) 296-1519
• UT Health RGV/Knapp Family Health Center, 2810 W. Expressway 83, Mercedes 78570, (956) 296-1831
• UT Health RGV Primary and Urgent Care, 3804 S. Jackson Road, Ste. #2, Edinburg 78539, (956) 296-3021