Lim: Herd immunity

Melanie T. Lim

WHILE there remains a lot that is unknown about Covid-19, it is believed that its herd immunity threshold is between 60 and 80 percent. This means that when between 60 and 80 percent of the population acquires antibodies of the virus, the virus will no longer be able to spread widely.

Herd immunity does not eliminate the virus but it does render it impotent to cause an epidemic. When community transmission becomes remote due to the presence of antibodies in the majority of the population, the virus ceases to be a public health hazard.

In the absence of a vaccine, however, the only way to acquire antibodies is through infection. So one might ask, why don’t we just allow the virus to spread like wildfire so it infects a large number of people and we achieve herd immunity quickly?

Well, because in the absence of a cure, we don’t want to operate on the principle of “survival of the fittest.” We cannot sacrifice the lives of the vulnerable to acquire herd immunity. One death is still one too many.

Still, even doctors are baffled how the virus kills the healthy twenty-something yet spares the seemingly vulnerable centenarian. Without a clear understanding of how the virus operates, allowing it to spread freely would be like playing Russian roulette.

Some of us will die. Some of us will survive. And we all leave it to chance.

And yet, in some of the worst-case scenarios like that of New York City when the city’s healthcare system was overwhelmed and at one point, cadavers were stored in parked vans outside hospitals, only 20 percent of the population had been infected.

That’s a very long way to go beyond 60 percent.

Herd immunity via mass infection will be intolerable. It will rip our hearts and souls. The loss of life will be unbearable. But the loss of control over our lives will be just as untenable. There is no safe way for this virus to spread. To acquire herd immunity, we need mass vaccination.

But a vaccine is not yet available. So as we wait with bated breath for its arrival, we must continue to practice safety protocols that slow the spread of the virus. Slowing the spread means prolonging the presence of the virus in our communities but we need to buy time to find a vaccine and a cure.

Slowing the spread also allows us to save as many lives as possible. If we let the virus go unfettered, it will swamp our hospitals with the sick and cause our healthcare system to collapse resulting in many unnecessary deaths.

Herd immunity is a long time coming. Brace yourselves for the long haul. Till the vaccine arrives, keep your masks on, continue to disinfect and stay home. Pray that everything we know about immunity still holds true. And if you can, ask for a miracle.