Most Likely Immune for Life

July 7, 2021

According to some brand new scientific studies if you’ve had covid-19, even a mild case, you have more than likely got long-term immunity. As is the case with recovery from many infectious agents, once you’ve had a disease (covid-19 included) and recovered, you’re likely to be immune for life.

According to some brand new scientific studies if you’ve had covid-19, even a mild case, you have more than likely got long-term immunity. Three recent papers published in “Nature” confirm that, as is the case with recovery from many infectious agents, once you’ve had a disease – covid-19 included – and recovered, you’re immune, most likely for life.

1) A group of researchers from Washington University School of Medicine showed evidence that long-lasting immunity to covid-19 exists in those who’ve recovered from the natural infection. New study – entitled, “SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans”, accepted and published – found that “individuals who have recovered from covid-19 have a substantially lower risk of reinfection with SARS-CoV-2”, and that “results indicate that mild infection with SARS-CoV-2 induces robust antigen-specific, long-lived humoral immune memory in humans.”

Authors write: “Long-lived bone marrow plasma cells (BMPCs) are a persistent and essential source of protective antibodies. Individuals who have recovered from covid-19 have a substantially lower risk of reinfection with SARS-CoV-2. Nonetheless, it has been reported that levels of anti-SARS-CoV-2 serum antibodies decrease rapidly in the first few months after infection, raising concerns that long-lived BMPCs may not be generated and humoral immunity against SARS-CoV-2 may be short-lived. We show that S-binding BMPCs are quiescent, which suggests that they are part of a stable compartment. Consistently, circulating resting memory B cells directed against SARS-CoV-2 S were detected in the convalescent individuals. Overall, our results indicate that mild infection with SARS-CoV-2 induces robust antigen-specific, long-lived humoral immune memory in humans.”

“Long-lived BMPCs provide the host with a persistent source of preformed protective antibodies and are therefore needed to maintain durable immune protection”, they say. “Overall, our data provide strong evidence that SARS-CoV-2 infection in humans robustly establishes the two arms of humoral immune memory: long-lived BMPCs and memory B cells.”

2) A second study from The Rockefeller University in New York – titled, “Naturally enhanced neutralizing breadth against SARS-CoV-2 one year after infection”, accepted by “Nature” but not published in its final form yet – states: “In the absence of vaccination antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable from 6 to 12 months”, and “The data suggest that immunity in convalescent individuals will be very long lasting.”

3) A brand new article published in “Nature” as well, and entitled “A long-term perspective on immunity to covid”, confirms that “clinical studies now indicate that immunity will be long-lasting.” Authors say: “A key question is, how long does this immunity last? Writing in Nature, (studies by) Turner et al (“SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans”)and Wang et al (“Naturally enhanced neutralizing breadth against SARS-CoV-2 one year after infection”) characterize human immune responses to SARS-CoV-2 infection over the course of a year.”

“Immunological memory”, thay explain, “is not a long-lasting version of the immediate immune reaction to a particular virus; rather, it is a distinct aspect of the immune system. In the memory phase of an immune response, B and T cells that are specific for a virus are maintained in a state of dormancy, but are poised to spring into action if they encounter the virus again or a vaccine that represents it. These memory B and T cells arise from cells activated in the initial immune reaction. … B cells have a dual role in immunity: they produce antibodies that can recognize viral proteins, and they can present parts of these proteins to specific T cells or develop into plasma cells that secrete antibodies in large quantities. About 25 years ago, it became evident that plasma cells can become memory cells themselves, and can secrete antibodies for long-lasting protection. Memory plasma cells can be maintained for decades, if not a lifetime, in the bone marrow. The presence in the bone marrow of long-lived, antibody-secreting memory plasma cells is probably the best available predictor of long-lasting immunity.”

“Turner and colleagues took up the challenge of identifying antibody-secreting memory plasma cells in the bone marrow of people who have recovered from covid-19 (called convalescent individuals). Memory plasma cells are rare, and those specific for a particular disease-causing agent will obviously be extremely scarce. Nevertheless, Turner and colleagues detected memory plasma cells that secreted antibodies specific for the spike protein encoded by SARS-CoV-2 in 15 of 19 individuals, approximately 7 months after infection. Notably, when the authors obtained samples 4 months later (11 months after SARS-CoV-2 infection), the number of such plasma cells had remained stable in all but one of the individuals analysed. Those plasma cells did not proliferate, which classifies them as bona fide memory plasma cells. Their numbers equalled those of memory plasma cells found in the individuals after vaccination against tetanus or diphtheria, and which provide long-term immunity to those diseases.”

“For SARS-CoV, a coronavirus very like SARS-CoV-2 that was originally identified in 2003 and causes severe acute respiratory syndrome (SARS), the continued presence of high concentrations of neutralizing antibodies in blood serum for more than 17 years was reported in 2020. Wang and colleagues’ results suggest that long-term immunity might also be expected for SARS-CoV-2. The authors report a follow-up investigation of serum antibodies and memory B cells specific for SARS-CoV-2 approximately one year after infection. The individuals studied had previously been analysed by Wang and colleagues’ group after six months, but it is only now, after a year, that the transition from an acute immune reaction to the generation of immunological memory has become evident. Wang et al show that, between 6 and 12 months after infection, the concentration of neutralizing antibodies remains unchanged.”

“The good news,” article concludes, “is that the evidence thus far predicts that infection with SARS-CoV-2 induces long-term immunity in most individuals.”

Full Study, entitled “SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans”
Study, entitled “Naturally enhanced neutralizing breadth against SARS-CoV-2 one year after infection”
Paper, entitled “A long-term perspective on immunity to covid”