“Whether you get infected by a virus, or not; or a bacterium, or not, is not a binary phenomenon – it depends on the amount of virus you get infected by,” said Sid Mukherjee, MD, before a live audience in New York last week. And the amount of virus you get is determined by what you do to protect yourself; crucially, the more barrier defenses you put in place the less likely you are to get sick. This is called the Swiss Cheese Theory of disease prevention where each ‘slice’ = 1 barrier. And it means we have more control over the coronavirus than we think. Moreover, Mukherjee says, the more people who do this, the safer all of us will be.
It’s based on the idea that no one defense is foolproof. Thus the more defenses you have in place the less the risk of the virus getting through all of them. Because in order to penetrate them all, says Mukherjee, there has to be “a straight line through [all of] the Swiss cheese.”
Getting your defense posture right matters as much now as ever. “We’re in for a whole lot of hurt,” says Dr. Anthony Fauci, describing the Trump administration’s disjointed, inadequate approach to controlling Covid-19 as US infections rise. As the New York Times reported yesterday, and in the chart below:
The United States on Wednesday recorded over 100,000 new coronavirus cases in a single day for the first time since the pandemic began … Twenty-three states have recorded more cases in the past week than in any other seven-day stretch. … Deaths related to the coronavirus, which lag behind case reports, have increased 21 percent across the country in the last two weeks.
Dr. Fauci says that the country “could not possibly be positioned more poorly” as winter approaches and colder temperatures lead people to gather indoors.
As the virus spreads, holiday gatherings — traditionally indoors and drawing people who have traveled from other places — have the potential to become superspreader events.
It therefore falls on each of us to prevent that from happening. The importance of keeping the amount of virus that reaches us as low as possible by masking, handwashing, physical distancing, and so on, was first introduced by Mukherjee in an essay in the New Yorker earlier in the year. Here’s his thinking underlying the importance of slowing down the virus:
. . the interaction between the virus and the immune system is a race in time. It’s a race between the virus finding enough target cells to replicate [in] and the antiviral response aiming to eliminate the virus. If you give the virus a head start with a large dose, you get higher viremia [virus in the bloodstream], more dissemination, higher infection, and worse disease.
So don’t let the perfect be the enemy of the good. Put as many barriers in place as often as you can and you’ll be helping yourself and those close to you. #decreasethedose