[Pearls Before Swine]

It does seem obvious.

I recall reading that the immune system usually ignores molecules below a certain (approximate) size. Even this virus is much larger than its entry spike. Maybe that’s part of the answer.

[Rockingham]

Like street cops on patrol against gang members, the immune system recognizes hostile intruders by one or more small gang signs in the form of specific features that antibodies and helper molecules chemically touch and identify. Cleverly, one drugmaker is making progress with a made to order molecule that seeks out and locks onto the coronavirus entry spike so as to permanently disable it.

In the end, of the more than a hundred drugs now being developed, a handful will make it through trials and, within a year or two, will provide a set of treatment options against the coronavirus. Most of the drugs being developed though -- at great expense -- will fail human safety tests, prove relatively ineffective in clinical trials, or will be too difficult or expensive to fabricate in useful commercial quantities. Along the way, we will learn a great deal about the coronasvirus.