Why knowing whether COVID survivors have antibodies, how long they last matters from Crain’s Detroit Business.
October 28, 2020
Five months ago on May 4, my health care worker wife Olga last took a full blood draw serology COVID-19 antibody test through University Physician Group, now Wayne Health. She was positive then, after having been exposed seven weeks earlier by a patient at a Detroit hospital around March 16.
On Oct. 20, we took a drive to a testing site in Dearborn for a follow-up test. A Wayne Health nurse took our blood and did a nasal swab for coronavirus, just in case.
Olga was negative for both, just as I was and have been all along; she had four previous positive COVID-19 tests and two previous 10-minute positive antibody tests.
To say Olga was disappointed she was negative for COVID-19 antibodies would be an understatement. All summer she wanted to donate convalescent plasma to the Red Cross that she believed contained plentiful amounts of antibodies. Three times we scheduled appointments, twice we went and twice she was sent home.
Once her blood pressure was too high at about 180. She often suffers from “white coat syndrome.” A second time, after waiting in a warm car outside for 45 minutes, her temperature was too high at 99.5, one tenth of a point too much for giving blood. The third time we canceled because she had a migraine.
But she was convinced all along that she was protected with COVID-19 antibodies. I often chuckled hearing her talk with fellow travelers, those who also contracted the virus and recovered. They empathized with each other very solemnly, talked about how lucky they were as opposed to the 225,000 who have died, and always ended with the exuberant phrase: We are immune! We are immune!
Early in the pandemic, experts thought coronavirus antibodies might last a year or two in people. Then stories surfaced about people in China getting reinfected, which made experts wonder how long antibodies would last.
About two months ago I started to read medical studies that seemed to suggest coronavirus antibodies might be short-lived, lasting less than three months. But it depended on the person, how sick, or how exposed the person was to the coronavirus — the so-called “viral load” — to how long a person might retain antibodies.
I told Olga and she refused to believe. “I have them. I know I have them. I feel I have them,” she insisted.
Her high fever, then cold flashes, loss of taste and fatigue lasted less than a week. She was symptom free in two weeks and she took a month off from work. But she continued to test positive for seven weeks. Still, she was cleared to return to work by a hospital occupational health nurse after answering a serious of questions.
As I wrote in four previous blogs, I was exposed time and again by Olga while she was positive. I tested negative multiple times for both for the virus and the antibodies. My doctor sources told me I am highly resistant. I am in email contact with two other guys in different parts of the country and they have had the same experience. Wives, very positive; they, stubbornly negative.
So, on Oct. 20, we rolled up to the outdoor testing site at ACCESS, Arab Community Center for Economic and Social Services, in Dearborn. We were early and there were already four cars ahead of us.
We were given a phone number and told to call it to be sent the COVID-19 testing application form. I wish I would have thought of this before we arrived because the application form was much longer than the one in May. It took us more than 10 minutes each.
Besides our names, insurance information and whether we had COVID-19 before, we were asked to fill in demographic information about whether we had experienced any problems with discrimination, transportation or access to food.
Wayne Health changed its application and welcome process since May to make sure people get the resources they need. The medical group has patient navigators on site to address social and medical care needs.
As a reward, of sorts, for our diligence in filling out the application/survey, we were given surgical masks, water and a small bottle of hand sanitizer.
Finally, we were greeted by Casey, a former Beaumont nurse who now works for Wayne Health. She expertly took our blood and swabbed our noses and we were done after an hour. We were told our results would come in three to five days.
Exactly three days later we got the results. By the way, 6 percent of the 33 people tested for the virus at ACCESS that day were positive, and 7 percent of 16 people were positive with antibodies.
Shortly after I got our results I sent a text message to Phillip Levy, M.D., an ER doctor, associate chair for research at Wayne State University School of Medicine and a co-investigator in numerous COVID-19 clinical trials. He also heads up WSU’s public testing outreach program.
I told Levy Olga was now negative, unhappy and confused, and asked what it meant.
“It doesn’t really necessarily mean much, it just means that her body is shifted to the next phase of the adaptive immune response, meaning that it’s no longer about having enough protection available at the ready,” Levy said in his best bedside manner. “That’s the antibody response. It’s about now having the memory to mount the response if you would need it.”
So, let me get this straight. Her negative test means she doesn’t have any COVID-19 antibodies left? You know she was counting on having those for a long time, right?
“Yes, what happens is that as soon as you’re exposed to the virus, certain types of cells start making these antibodies as part of that immediate response. Those cells live to produce the antibodies for as long as the body thinks it might need to protect itself. And that peak, (we now know from research) is about 50 days or seven weeks.
“At that point in time, those neutralizing antibodies start to start to die off. They’re short lived. Once they die off, you’re not consistently making that antibody and it will disappear from your from your circulation,” Levy said.
He knew Olga was upset about losing her coronavirus antibodies, ones she had felt could be her ultimate saviors, in case wearing N95 masks, gloves, gowns and constant handwashing at work might fail.
“Olga retains the ability to start to make them again, if the need were to arise in the future. There is an adaptive immunity response to the cororavirus. There was a study (Sept. 11) in the Journal of the American Medical Association that shows the timeline of the response,” said Levy, adding the the peak of the longer-lasting igG antibodies are at the seven-week mark.
Doctors understand there are two types of immune response, he said. One is innate, a response from your immune system that responds to attacking bacteria, viruses or other invaders when you are exposed to something harmful. As your body reacts to invaders, your immune system creates antibodies to do kill or neutralize infections. The response typically peaks about 50 days into an infection, Levy said.
“But that’s not the only thing your body has. After the initial antibodies go away, in the background, your body has built up memory towards that thing it was exposed to with what are called T cells and B cells,” Levy said. “So should it be exposed to it again, the response would be triggered again,and you would have more neutralizing antibodies, meaning they all kill and wipe out the virus completely.”
During an immune response, B and T cells create memory cells. These are clones of the specific B and T cells that remain in the body, holding information about each infection the body has been exposed to.
Levy said researchers now believe it is normal that coronavirus antibodies wane over time and the T and B cells act like sentries, waiting to be activated.
“Even with asymptomatic people that long-term immunity with T cells builds up. Your body will be able to recognize the infection in the future and then respond more quickly,” he said.
Hmm, OK, but how do we know these T and B cells have memory with coronavirus? Are there studies that prove that, or is that just theory?
“That’s just the understanding of the adaptive immune response. It’s the way adaptive immunity works. There are some studies that have looked at the inducibility of those T cells in individuals. We’re doing an article on it. But there does seem to be this buildup of this T cell response that can be triggered by re-exposure,” he said.
However, Levy said nobody currently knows why some people will get reinfected.
“We’ve seen in a handful of cases. There is still a lot of the uncertainty about how the body responds to this particular virus versus others, where the response would would generally follow the same type of pattern,” he said.
While Olga lost her antibodies between about two months and seven months, Levy said some people can retain coronavirus antibodies for up to a year.
For example, New York Times reporter Margaret Renkl wrote Oct. 26 about her firsthand experience with coronavirus and her long-lasting antibodies. She was infected in February and tested positive for antibodies six months later in August. “Being a survivor means you can help,” she wrote.
Levy said there is still much doctors don’t know about coronavirus and the antibodies it produces. Several studies are underway nationally to evaluate how long coronavirus antibodies last. Earlier this year, the Michigan Department of Health and Human Services began collecting data on the long-term impacts of COVID-19 antibodies based on the multiple antibody tests the FDA has approved.
Retaining antibodies in your body for a long time “depends on how how strong the initial inoculation was and some other factors related to the individual,” said Levy.
“It’s because the body isn’t fighting anything more. We don’t need to produce them and you don’t need them to be around,” Levy said.
A Wayne State research team led by Pranatharthi Chandrasekar, M.D., chief of infectious diseases, found the viral load of coronavirus in nasal samples in patients with COVID-19 decreased as the pandemic has progressed this year. The decline was associated with a decrease in the rate of death from the disease between April 4 and June 5.
The study included 708 patients hospitalized with COVID-19 at DMC Detroit Receiving Hospital, Harper Hospital and Sinai Grace Hospital. Almost half of the patients in the high viral load group died, compared to 32 percent and 14 percent in the intermediate and low viral load categories, respectively.
Levy said Olga, who was wearing a flimsy surgical mask at the time she was coughed on, could have received an initial low coronavirus viral load exposure.
“She recovered in fine fashion, but she was a prolonged carrier. Whether her prolonged carrier case had anything to do with the type of antibody response that she developed, we just don’t know,” he said. “That’s why looking at what the antibodies do to the virus, when they’re in contact with them, is an important thing to understand.”
Levy said studies are starting to show that the intensity of the immune response is definitely related to the amount of viral load with which you’re exposed. There are always people who are outliers and develop a profound immune response to smaller viral loads.
Still, most researchers believe people with more severe COVID-19 infection probably have more antibodies, which could possibly protect them from reinfection for a year or more. Milder infections lead to fewer antibodies and provide shorter-term protections. Reinfection is possible.
Continue reading, “Why knowing whether COVID survivors have antibodies, how long they last matters” from Crain’s Detroit.
Learn more about Phillip Levy, M.D., MPH, FACEP, FAHA, FACC.
