Dr. Farber’s COVID-19 update 37

Today I am going to discuss the omicron variant, from three perspectives: contagiousness, vaccination, and the concepts of isolation/quarantine/lock-down.

Omicron is clearly much more contagious than previous variants. However, it is also clearly milder. This is not unexpected. An infection needs hosts in order to replicate and spread, and if it kills off too many hosts, it will not be able to hang around. This is what happened with the Black Death in the 14th century, which eventually disappeared (but not without killing off perhaps 50% of Europe), without our having vaccines, medicine, or even a good understanding of hygiene. I do not expect Omicron to be as deadly as when COVID-19 first appeared, although that does not mean we should underestimate it.

(As an aside, as an indication of how people still do not understand the devastation COVID-19 can bring, I recount the following. Today, I overheard someone telling a friend “Omicron is no big deal. I had it, took some monoclonal antibodies” (which, by the way, were probably not medically indicated), “and only had sniffles. I feel fine now.” I almost expected him to add, “I don’t know why so many people choose to be intubated.”)

That brings me to vaccines. When COVID-19 first appeared, many people, including those in authority who should have known better, dismissed it as just like the flu. They were of course wrong. It was vastly more dangerous, and soon filled up hospitals, with high death rates as well. Omicron, does look more like the flu, being milder, but even so it is still expected to wreak more havoc, and more deaths, than even a bad flu season does. It is also more like the flu regarding vaccine effectiveness.

In a given year, the flu vaccine is perhaps only 50% or so effective at preventing disease. However, it is much more effective at preventing serious illness/complications, and highly effective at preventing death. The current vaccines for COVID-19 seem similar regarding their effectiveness. They do protect against illness, but nowhere near the numbers we would like. However, the vast majority of hospitalizations and deaths are occurring in the unvaccinated (even though they make up a minority of the population), because the vaccine is effective here. Please get yourselves, and your eligible children, vaccinated.

You have seen sports teams throughout the country decimated by the virus, even though, supposedly, the vast majority of athletes are vaccinated. Vaccine remains one component of prevention. With athletes, we have unmasked people in close contact with each other, breathing rapidly as they exercise and thus expelling more germs, and not constantly washing their hands. Hand washing, and particularly mask wearing, remain vitally important, even if not mandated (or even where actively discouraged, as in some parts of the country, which I predict will soon become the hot spots for the virus as it spreads).

Should we have lock-downs again? I hope very much not to have to resort to them this go around, and expect to be able to avoid them with this milder form, relying on methods of reducing, but not eliminating, spread. School lock-downs, in particular, are a major concern for me, and should be avoided if at all possible. They are disruptive to the economy, as parents have to stay home to care for their children. We learned last year that they are poor replacements for in-person learning. Lastly, they have, not unexpectedly, negative consequences on the health of children, not just in mental health (depression rates have risen), but also physical health (obesity, already a major health issue, has become more prevalent as well). Along the lines of keeping schools open, I do note that, in Northern Virginia, many private schools were able to stay open last year, before we had vaccines. They did have the advantage of smaller classes, and it was no doubt easier to enforce mask wearing and hand washing. I take this as an indication that we should be able to keep schools open this year.
The CDC has just recommended shorter quarantine and isolation periods (I will refer to just quarantine from here on out, but the principles are the same for isolation). However, not all jurisdictions are going along with this. The difficulty here is that the variant is new, and we are still collecting data, but decisions have to be made in advance of this, realizing that recommendations will almost certainly change as we learn more. From a point of view of keeping schools, and the rest of society, open, there are obvious advantages to shortening quarantine periods. On a theoretical basis, I am comfortable with the shorter periods, and for this I rely on studies from England starting in the 1940s, which used the ‘common cold unit’. In this, scientists would introduce cold viruses into the noses of volunteers under different conditions, and see what happened.

One discovery was that the temperature of the room did not affect whether a person would then develop a cold. This is why, when parents ask me to tell their child to wear a hat in the winter so they won’t catch a cold, I cannot comply. Colds are more prevalent in the winter not due to feeling cold, but to being indoors and in closer contact with people (less ‘social distancing’, in current parlance).

We also learned that it takes a large number of viruses, not just a handful, to cause a cold. This is true of most, but not all, viruses; measles, for example, can be picked up with a very small inoculum, to use the technical term, which is why it is so highly contagious. When you have a cold, you can start breathing out germs before you have symptoms, which is why you can catch a cold from someone who is not ill at the time. You continue to emit germs for some time, but the number drops rapidly, to an amount below that which tends to cause colds in others, which is why you are not contagious for long with a cold, even though the symptoms may linger for weeks. I expect the same to be true for omicron, although, as stated, we do not have sufficient data to back this up yet. If true, even though you may still be harbouring the virus, and have an antigen test which stays positive for some time, a positive test later on in the illness would not necessarily indicate infectiousness. (In contrast, a negative test, if accurate, does mean no virus, and confirms no contagiousness). The idea is therefore that, after five days, you are not producing enough germs to pass it along, and can come out of quarantine if feeling better. Of course, this is theoretical, and it will still be important to get vaccinated, wear masks, wash hands, and try social distancing when possible, all measures which have clearly been shown to be effective, while we wait for more data to appear.

Most importantly, still, everyone knows what they need to do, and should be doing, to prevent the disease in themselves and their children. Please do your part.
Have a happy and healthy 2022.