Let’s Try This Again: Herd Immunity

A few months ago, I wrote an essay explaining why allowing coronavirus to spread to the point of herd immunity is a stupid idea. Apparently the argument didn’t take. With my hospital filling up with COVID cases again, I’m busy, so let’s just set aside the niceties and get to the facts.

1. It will lead to unnecessary deaths, even in the young.

The idea is to let coronavirus run wild in the young and healthy, and when enough healthy people are immune, the disease will stop spreading.

Sounds good, except for the false assumption that the young will never be harmed from it. Even among the healthy, the death rate is about half a percent. So if you infect everyone in the Texas A&M campus, which numbers about 55,000 students, you end up with 275 deaths. If a building blew up on the Texas A&M campus and killed 275 students, it would be a national tragedy. But, by this thinking, 275 coffins exiting College Station one at a time is just collateral damage. 

No. That’s obscene.

And even more importantly, it will not be possible to isolate high-risk populations from the young people we intentionally infect. Young people go home for the holidays. They have weddings, they attend graduations and funerals with older people. They go to the grocery store, to church, to hair salons. They will bring COVID with them, wherever they go. Since we are going to do nothing to stop them from getting it, the risk will be fairly high that any young person who mixes with older people will be infected.

There are 55 million Americans over 65, and 112 million over 50. This would be our vulnerable population. It is simply not possible to isolate 55 million people, let alone 112 million from the rest of America. The very idea is absurd on its face.

We are already isolating the nursing homes. Many schools are closed, or operating with many normal activities cancelled. Teachers are doing classes online, and people at high risk are already trying to protect themselves as best as they can. And coronavirus is spreading anyway.

We can’t even get people to wear masks, and the White House thinks it can prevent COVID from passing from millions of young people to 100 million or more vulnerable people?

Don’t make me laugh.

2. We will have a hard time telling when the infectious phase of this “plan” is over.

Let’s say we do infect colleges and high schools and other young populations so they can be immune. When is it safe for everyone else to come out? When have we achieved this mythical herd immunity? The only way to determine this is to test young people in huge numbers and figure out how many are immune. This will be expensive and difficult, and since we don’t know exactly what percentage of the population has to be immune for herd immunity to kick in, we may find ourselves not knowing, even after all that work.

3. The process of determining immunity is not straightforward.

There is an antibody test. But the antibody test is considered experimental, and it is not known if a positive test means a person is completely immune. Antibody levels in the blood very likely correlate with immunity, but there is also a thing called cellular mediated immunity that does not correspond with antibody levels. Thus, It is possible that some people with negative tests could be immune. And it has not been proven scientifically that a person with antibodies is immune, either. It is just assumed.

Since there is not a scientifically agreed-on standard to determine immunity, it could be a lot harder to tell who is immune and who isn’t than herd immunity people think. Remember, many people who get COVID have minimal symptoms. So in a large college population, for example, maybe only 20% of the students will get sick enough to notice that they have COVID. As for the rest of them, how will we know if they had it? We will have to test them. All of them. And if we find that a student has some antibodies to COVID, but not enough to meet the cutoff for full immunity, what does that mean? At this time, no one is sure.

4. There may not be permanent immunity to COVID.

Most scientists feel that someone who is infected with COVID will be immune after recovery, but this protection may not be permanent. This is based on our understanding of other coronaviruses (SARS-Cov-2 is not the only strain of coronavirus). These non-COVID coronaviruses, many of which cause the common cold, can re-infect people every year.

One recent study showed a decline in antibodies in about a quarter of all subjects after three months. The CDC, at this moment, thinks immunity should last six months, but officially recommends that anyone who had COVID-19 should assume he or she could be susceptible again after only three months.

And so, a previously infected population could be susceptible to an epidemic as soon as 3 months later, and very likely within a year. This means if we just let the young get infected, all we are doing is making them think they are immune, so they can forget all precautions and then get it again later. If that sounds dumb to you, you’re catching on.

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So there is anything we can do to stop COVID? Yes, there is plenty we can do. We can take all practical precautions and slow the rate of spread down to a very low level. This buys us time to distribute a vaccine, which will slow the rate down even more, giving us time to devise a permanent solution. The permanent solution will probably involve some combination of vaccination, quarantining, contact tracing, and long-term masking and social distancing. This approach is a sensible plan that will minimize deaths and protect our health care system from being overwhelmed. It is the smart solution, but one that requires a little more effort than turning COVID loose and going home for a nap.