Nav: Home

In recovering COVID-19 patients, antibodies fade quickly

October 16, 2020

Washington, DC - October 16, 2020 - In the absence of approved, effective treatments for COVID-19, some hospitals have been treating patients with severe COVID symptoms with blood plasma from recovering patients. The blood of recovered patients contains antibodies that act against the coronavirus. While plasma hasn't yet shown a benefit in randomized trials, some small retrospective studies suggest it may reduce illness severity and reduce hospitalization time.

This week in mBio, an open-access journal of the American Society for Microbiology, researchers report that antibody levels in the blood of COVID-19 patients drop rapidly during the weeks after their bodies have cleared the virus and symptoms have subsided. If convalescent plasma is ultimately shown to have a clear benefit, the authors concluded, then it needs to be collected during a specific window of time after recovery. However, recovering patients can't donate blood until at least 14 days after symptoms have subsided, to give the body time to clear viral particles.

"We don't want to transfuse the virus, just transfuse the antibodies," said Andrés Finzi, Ph.D., at the University of Montreal, in Canada. "But at the same time, our work shows that the capacity of the plasma to neutralize viral particles is going down during those first weeks."

The spike protein of SARS-CoV-2 plays a crucial role in helping the virus grab and invade host cells. Antibodies produced by the body's immune system bind to a part of this protein and block the capacity of this "key" to engage with the host's cellular "lock", said Finzi, preventing the viral particle from infecting a cell host.

Previous studies suggest that antibodies against the SARS-CoV-2 spike protein peak 2 or 3 weeks after the onset of symptoms. Findings from an earlier cross-sectional study by Finzi's group, involving more than 100 patients, suggested that the ability of plasma to neutralize the virus decreased significantly between 3 and 6 weeks after symptom onset.

In the new longitudinal study, Finzi and his colleagues analyzed blood samples collected at one-month intervals from 31 individuals recovering from COVID-19. They measured levels of immunoglobulins that act against the coronavirus S protein and tested the ability of the antibodies to neutralize the virus.

The researchers observed variation on the level of individual patients but identified a consistent overall signal: The levels of Immunoglobulins G, A, and M that target the binding site decreased between 6 and 10 weeks after symptoms began. During the same time period, the ability of the antibodies to neutralize the virus similarly fell.

Finzi's group has continued to study blood samples from the patients. Understanding how the levels of antibodies change over time, he said, is critical not only for optimizing the use of convalescent plasma but also for understanding vaccine efficacy and whether or not previously infected people are at risk of re-infection.

"How long do antibodies protect you?" he asked.

Finzi's other research focuses on the immune response to human immunodeficiency virus, or HIV, which differs dramatically from SARS-CoV-2.
-end-
ASM is keeping the pulse on the SARS-CoV-2 pandemic with the COVID-19 Research Registry of top-ranked research articles curated by experts. In the eye of a pandemic, this curated database will ensure that scientists, journalists and the public have an efficient way to find the timeliest and most valuable SARS-CoV-2/COVID-19 research from the latest journal articles and preprints.

The American Society for Microbiology is one of the largest professional societies dedicated to the life sciences and is composed of 30,000 scientists and health practitioners. ASM's mission is to promote and advance the microbial sciences.

ASM advances the microbial sciences through conferences, publications, certifications and educational opportunities. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.

American Society for Microbiology

Related Antibodies Articles:

Mussels connect antibodies to treat cancer
POSTECH research team develops innovative local anticancer immunotherapy technology using mussel protein.
For an effective COVID vaccine, look beyond antibodies to T-cells
Most vaccine developers are aiming solely for a robust antibody response against the SARS-CoV-2 virus, despite evidence that antibodies are not the body's primary protective response to infection by coronaviruses, says Marc Hellerstein of UC Berkeley.
Children can have COVID-19 antibodies and virus in their system simultaneously
With many questions remaining around how children spread COVID-19, Children's National Hospital researchers set out to improve the understanding of how long it takes pediatric patients with the virus to clear it from their systems, and at what point they start to make antibodies that work against the coronavirus.
The behavior of therapeutic antibodies in immunotherapy
Since the late 1990s, immunotherapy has been the frontline treatment against lymphomas where synthetic antibodies are used to stop the proliferation of cancerous white blood cells.
Re-engineering antibodies for COVID-19
Catholic University of America researcher uses 'in silico' analysis to fast-track passive immunity
Seroprevalence of antibodies to SARS-CoV-2 in 10 US sites
This study estimates how common SARS-CoV-2 antibodies are in convenience samples from 10 geographic sites in the United States.
Neutralizing antibodies in the battle against COVID-19
An important line of defense against SARS-CoV-2 is the formation of neutralizing antibodies.
Three new studies identify neutralizing antibodies against SARS-CoV-2
A trio of papers describes several newly discovered human antibodies that target the SARS-CoV-2 virus, isolated from survivors of SARS-CoV-2 and SARS-CoV infection.
More effective human antibodies possible with chicken cells
Antibodies for potential use as medicines can be made rapidly in chicken cells grown in laboratories.
X-ray experiments zero in on COVID-19 antibodies
An antibody derived from a SARS survivor in 2003 appears to effectively neutralize the coronavirus that causes COVID-19, opening the door for speedy development of a targeted treatment.
More Antibodies News and Antibodies Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Sound And Silence
Sound surrounds us, from cacophony even to silence. But depending on how we hear, the world can be a different auditory experience for each of us. This hour, TED speakers explore the science of sound. Guests on the show include NPR All Things Considered host Mary Louise Kelly, neuroscientist Jim Hudspeth, writer Rebecca Knill, and sound designer Dallas Taylor.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at Radiolab.org/donate.