During the past eighteen months we have all heard the term ‘herd immunity’ bandied about frequently, but I wonder how many people know what it really means and have a grasp of what those flouting it were even talking about. I was loathe to even tackle the issue before now, because emotions were so high and empathetic listening so low it would only have added to the confusion.
Now that we might finally be seeing a light at the end of the tunnel on this dreaded pandemic that isn’t an oncoming train, I think it might be safe to bring the issue up and try to shed a little light on it.
First, just what is herd immunity? Herd immunity is defined as ‘resistance to spread of an infectious disease within a population based on pre-existing immunity of a high proportion of individuals as a result of previous infection or vaccination.’ Before the invention of vaccines, the only way populations achieved herd immunity was through enough people being infected who were then immune from further infection, thus limiting the chance of new infections.
The problem with achieving herd immunity in this way is that diseases that can kill, do just that in the process of creating a relatively immune surviving population. It worked for diseases that do not mutate, but those that are constantly mutating and adapting, like influenza, will continue to infect and ravage populations until vaccines are developed and a sufficient percentage of the population is vaccinated.
There are those, believe it or not, who wanted to let Covid-19 run its course without vaccination or protective measures such as masks or social distancing. Many softened this view by saying that ‘vulnerable’ individuals should be protected, but otherwise healthy people should be allowed to be infected. In terms of what Covid-19 has done, even with the development of several effective vaccines, the idea of not taking protective measures and letting nature take care of things gives me the chills. Sweden tried it, and the results were catastrophic. They did much worse than the rest of the Scandinavian countries which implemented stringent measures early in the pandemic.
Here in the U.S., we implemented a patchwork system of measures, with some states doing more than others, with predictable disastrous results. Our death toll was over 600,000, and while infections, hospitalizations, and deaths are down significantly, they have yet to reach zero. Oh, and by the way, it was here that there were people suggesting we just let it do its thing until we reached herd immunity, or in one case ‘herd mentality.’
Thank goodness, we didn’t. In order to achieve herd immunity, from one-half to two-thirds of the population would have to have been infected. With the three percent mortality rate we did experience, that would have meant as many as six million dead of the 220 million or so infected. Let that number sink into your brain for a while.
The other thing about herd immunity that got little notice during all the heated discussions I heard was the fact that achieving it does not mean there will be zero transmission. If 80 percent of a populations is immune that means that four out of five people who come into contact with another infected person will not get sick or spread the disease. That’s still a potential twenty million infections in the population, with over 200,000 deaths. Far below what we experienced this time, but still an enormously high casualty rate.
One has to wonder what goes through the minds of people who think like this, who can so casually propose a course of action that would lead to so many deaths. I guess it’s just a validation of the old saying, ‘One death is a tragedy, while a million deaths is merely a statistic.’ Maybe some people can view it like that, but not yours truly. I lost two nieces to Covid, and nearly a dozen colleagues and friends. To me, the deaths from this disease are not a statistic. They represent real people, who are missed by someone.
Then, there are the other things that a country will suffer when the natural herd immunity path is taken that were not really discussed. Pressure and demands on the health delivery system increases exponentially. Work hours are lost due to illness, with potential long-term negative economic impacts, and other social and economic disruptions happen that take a long time to remedy.
That’s what natural herd immunity means, so remember that the next time you hear some pundit tossing the term around. – NWI
