Analysis of SARS-CoV-2 immune response several months post-infection hints at protective immunity

January 06, 2021

Researchers who studied antibody and immune cell responses in more than 180 men and women who had recovered from COVID-19 report these patients' immune memory to the virus - across all immune cell types studied - was measurable for up to 8 months after symptoms appeared. The results indicate "that durable immunity against secondary COVID-19 disease is a possibility in most individuals," the authors say. As the number of daily COVID-19 cases worldwide continues to mount, whether an initial infection with SARS-CoV-2 leads to long-lasting protective immunity against COVID-19 remains a question. Studying the nature of the humoral response to the virus, which includes an antibody response, and of the cellular immune response, which includes B cells and T cells, over periods of six months after symptoms start could help inform protective immunity's duration. To do this, Jennifer Dan and colleagues recruited more than 180 men and women from the United States who had recovered from the disease. The majority had had mild symptoms that did not require hospitalization, though 7% were hospitalized. Most subjects provided a blood sample at a single time point, between six days and eight months after symptoms took hold, though 43 samples were provided at 6 months or more following symptom onset. In 254 total samples from 188 COVID-19 cases, Dan and colleagues tracked antibodies, B cells (which produce more antibodies), and two types of T cells (which kill cells that are infected). Antibodies, including to viral spike protein components, only exhibited modest declines at six to eight months after symptom onset. T cells, meanwhile, showed only a slight decay in the body, while B cells that recognized features of the SARS-CoV-2 virus grew in number in some cases, the authors say. While the authors caution that "direct conclusions about protective immunity cannot be made on the basis of [their findings] because mechanisms of protective immunity against SARS-CoV-2 or COVID-19 are not defined in humans," they also say that several "reasonable interpretations" can be made from their study. These include support for resting immune memory compartments potentially contributing "in meaningful ways to protective immunity against pneumonia or severe secondary COVID-19," the authors write.

American Association for the Advancement of Science

Related Antibodies Articles from Brightsurf:

Scientist develops new way to test for COVID-19 antibodies
New research details how a cell-free test rapidly detects COVID-19 neutralizing antibodies and could aid in vaccine testing and drug discovery efforts.

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.

Read More: Antibodies News and Antibodies Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to