Back to technical issues:
Several groups are looking for antibodies that can be used to treat coronavirus, as opposed to looking for antibodies to determine if one was infected.
Preliminary antibody explanation for understanding the article:
Consider the surface of the virus as a limited number of proteins which are exposed so that antibodies could interact with them.
Each protein of a particular kind (such as the spike protein) will have a particular pattern of amino acids and/or protein modifications to which antibodies can bind. The binding site of an antibody is called an epitope.
Antibodies are produced by immune cells. Each cell produces many copies of a single kind of antibody that binds to a particular binding site on the exposed surface of the protein it binds to. During an immune response cells producing antibodies that effectively bind target divide and make more of the cells making the same antibody (sometimes with refining minor mutations). This is called clonal selection. As a result, overall, the body produces the same antibody in greater numbers (this can take weeks).
(for this figure like of the pathogenic bacterial cell as the virus)
An antibody can bind to its target strongly, weakly, or in between. Strong binding antibodies will stay bound longer and generally have stronger effects (binding is stochastic, the antibodies can come and go depending on their binding properties).
Since the immune system has millions (or more) cells doing this, a normal immune response can have lots of different antibodies that bind to different distinct places on a virus surface protein.
More antibodies binding to a single target will generally have a stronger immune response.
Antibodies can either directly block their targets function by blocking or occupying its binding site (or enzymatic site, depending on the function of the target molecule), or they can just label the virus (or whatever else they might be binding) for follow up by the immune system which could result in eating the virus, killing an infected cell or an invading bacteria.
This Science news article reviews the efforts of several (but not all) of these groups (see below).
They are looking for antibodies that will prevent the Coronavirus from binding and entering cells.
This approach is similar to one that was previously posted about using the protein that is bound by the virus's spike protein and flooding a person's blood with this protein which would bind all (or enough to be effective) of the proteins spike protein's binding sites to prevent them from binding their cellular targets, and thus preventing them from getting into cells.
Several approaches described.
They are focused on making/identifying monoclonal antibodies (antibodies that are all molecularly the same and bind the same part of the target protein), but to produce a more effective response want to have more than one kind of antibody so more of the spike protein is bound by antibody. Therefore they want to combine different monoclonals into a cocktail (mix of two or three different antibodies) that can be used to treat patients.
This approach seems to have worked OK with the Ebola virus.
The technical issues of producting the antibodies are not immense but intricate and involve a lot of work.
They are using clever strategies to target antibodies that are more likely to be useful.
The scale-up may present challenges.