We are less than a year into the devastating COVID-19 pandemic but already there is cause for optimism about our ability to cope with the disease in the relatively short term. This has hinged on the outstanding efficiency and speed of the global scientific community. Within weeks of the first outbreak in Wuhan, China, the virus that we now know as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) had already been sequenced in its entirety. Phase one clinical trials of candidate vaccines began mere months later.

However, questions remained about the nature of SARS-CoV-2 antibodies and their role in securing homologous post-infection immunity.

The Trouble with SARS-CoV-2 Antibodies

An enduring pain point in the COVID-19 vaccine development pipeline has been the uncertain and often conflicting information we have available to us about SARS-CoV-2 antibodies. High-quality serological testing has confirmed infection with SARS-CoV-2 by detecting considerable immunoglobulin (IgG) responses to the nucleocapsid and spike proteins. The duration of this immunological response is considered to be analogous to that of SARS-1, where that most cases result in a measurable antibody response between 10—21 days following infection. But the longevity of this SARS-CoV-2 antibody response is uncertain.

How Long Do SARS-CoV-2 Antibodies Last?

We know from past coronaviruses that SARS antibody responsiveness wanes over time, and recent research seems to confirm that the same is true for COVID-19. Imperial College London noted a drop in positive antibody tests of 26% within three months of the first testing round. This was dire news for policy makers nurturing hopes for so-called herd immunity.

What This Means for Long-Term COVID-19 Immunity

It has been noted that differences in viral dosages, transmission pathways, severity of infection, and even the date of infection could influence immunity duration. Our understanding of the biological and genetic risk factors associated with SARS-CoV-2 severity are unfortunately lacking. This makes it difficult to assess the long-term humoral immunity. However, more comprehensive studies into adaptive immunity have identified cellular immunological responses as critical in securing long-term protection from COVID-19. The Imperial College London report failed to note the role of cell-mediated immune responses such as T-cell responses against the SARS-CoV-2 spike protein. So, the demonstrable waning of SARS-CoV-2 antibodies was not necessarily a fatal blow for COVID-19 immunology.

SARS-CoV-2 Antibodies from ACROBiosystems

At ACROBiosystems, we believe that SARS-CoV-2 antibodies are critical to gathering the large quantities of data necessary to fully characterise the COVID-19 virus with a view to understanding both antibody- and cell-mediated immune responses. We have accelerated development of matched antibody pairs, neutralizing antibodies , and human-derived antibodies  to support biopharmaceutical developers manufacturing advanced serological tests and carrying out vaccine research.

Among the greatest reasons for optimism is the news that Pfizer has successfully conducted phase three evaluations of a novel COVID-19 vaccine based on messenger RNA (mRNA) – the first of its kind. Immunologists are cautiously enthusiastic about these published results, heralding it as an enormous step forward in our ability to combat the virus.

Are you carrying out pioneering COVID-19 research and need SARS-Cov-2-antibodies? Contact a member of the ACROBiosystems team today to discuss free samples.

Sources:

https://www.ecdc.europa.eu/en/covid-19/latest-evidence/immune-responses

https://www.the-scientist.com/news-opinion/what-do-antibody-tests-for-sars-cov-2-tell-us-about-immunity--67425

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32137-1/fulltext

https://www.bbc.co.uk/news/health-54696873