Fifth Column

Dedicated reader will recall earlier missives where the notion that Covid-19, et seq, have been, on the whole, trading virulence for contagion. Not, of course, that the wee critter makes such a conscious decision. Not enough brains for that; it's just that the Darwin imperative (that the environment chooses the winners) rewards contagion. We know that the virulence end of the spectrum, SARS and MERS, have been very limited in time and space. They kill off hosts too quickly. Which led me to muse that the main branch of Covid-19, currently Covid-ο, will continue to spit out variants, and that the trade of virulence for contagion will continue.

Two aspects remain unknown:
- will the Covid-ο variant not only be the basis for future variants, but that this main branch will carry on with the less virulent individual mutations.
- will we also see, as with Covid-ε, the occasional more virulent, but limited, variant.

I'm betting yes to both, as dedicated reader will remember. Until last night, I found myself alone, wrt the professionals. But, then "60 Minutes" ran an update on Covid-19, and one of said professionals offered up that very possibility (the former, not yet the latter).

Here

Dr. Jon LaPook: Is it possible that the coronaviruses that now cause the common cold long ago began as fiercely, as dangerous, as deadly as SARS-CoV-2 and that, over time, it became weaker and weaker? Now we have the common cold?

Paul Duprex: Oh, I would say it's more than possible. I would say it's very likely. But we just have to wait and see where the virus ends up, and that's just good science. Scientists follow the virus, keep a close eye on it, and we understand how that virus changes over time and where it will go.

This is Dr. Duprex.

A truly intriguing possibilty that follows from this possiblity, is the reduction of the common cold. There are four coronaviruses identified with the common cold. Together they account for ~40% of colds. Add a fifth, and we could be looking at half of colds caused by a class of virus for which we can make vaccines. The major issue, beyond whether it's a waste of resources to vaccinate against 'just a cold', is whether Covid-19 will settle down to a more stable virus. We know that endemic flu is caused by many viruses, and the professionals have the burden of guessing which one(s) will be prevalent for the coming season, so that the flu shot can target those strains. The flu shot fails some seasons, not because the shot is bad, per se, but because the targeted strains turn out not to be the most prevalent. The vaccines work, but only if the targeted viruses appear. The same could end up being the case with Covid-19 in the future.

We surely know from Covid-ο that Covid-19 can spawn a variant, cycle up, and cycle down far faster than the drug industry can respond with a targeted vaccine. Luckily, Covid-δ didn't break the 'trade-off rule', by being not just a bit more virulent and contagious, but a lot of both. That's a bullet I'm not eager to dodge again.