Tuesday, April 21, 2020

The Coronavirus Crisis dilemma: Immunizing the herd without a vaccine to end the Great Economic Lockdown of 2020 could kill 7 million Americans

In the face of the Coronavirus Crisis of 2020, responsible local and state governments initiated the Great Economic Lockdown of 2020 to minimize deaths and hospitalizations from Covid-19.

Today two sources of political pressure to "open" the Great Economic Lockdown of 2020 are rising.

One is the obvious group of "you can't do that to me" folks who are outwardly seeming to advocate a "give me liberty or give me death" philosophy while ignoring what they are really advocating - "give me liberty to spread disease and kill you." Ironically, most are the folks that claim to be "Pro-Life" who are advocating "Pro-Choice" as their right. Donald Trump is cheering them on because he needs them to win reelection.

President George Washington would be turning over in his grave, of course. As he made clear during the Whiskey Rebellion personally leading troops to squash the protest, nothing in the Constitution or American history guarantees freedom from government regulation. We are a government of laws, not men.

But the sign-waving, out-on-the-streets-with-guns protesters are not alone.Not quite as obvious are those criticizing the lack of progress on badly needed testing that's holding up ending the Lockdown, the other folks questioning whether we can wait.

A good example is Dear Governor Newsom: Where Is Our Coronavirus Testing? subtitled A letter to the much-lauded California governor — because we know very little, and it’s frustrating. It was written by Sharon Waxman, the founder, CEO and Editor in Chief of TheWrap. She is an award-winning journalist and best-selling author, and was a Hollywood correspondent for The New York Times.

I have to believe that Waxman may have done well in college - she graduated from Barnard College in 1985 and from St. Antony's College, Oxford University in 1987 with a Masters of Philosophy in Modern Middle East Studies. But she must have avoided math classes. And her criticism reflects others who can't do math.

You see, there are about 340,000,000 people (that's 340 million) in the United States. If we tested 1,000,000 (that's 1 million) a day, it would take 340 days to test everyone.  And based on California's share of the population Californians would be testing 117,000 people a day.

Fortunately, however, we don't need to test everyone to know if we've achieved "herd immunity."

In the midst of this Covid-19 pandemic officials or public health specialists refer to "herd immunity." Herd immunity is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, whether through previous infections or vaccination. This provides a measure of protection for individuals who are not immune.

It sounds simple enough. But it takes a substantial percentage of the population to become immune to protect those who are not immune. If enough people are vaccinated, we have herd immunity.

If there is no vaccine for a disease, enough people have to get the disease and survive to achieve herd immunity. Another way to explain it is that a population reaches herd immunity when enough people have survived to achieve the herd immunity threshold (HIT). Oh, and inevitably and unavoidably that means enough people have died!

Consider the chart at the right. Smallpox is a good example of a disease. If smallpox appears in a localized population of 1,000 people and  980 fall ill and 80 survive, those 80 are immune offering "herd immunity" resistance against a future epidemic developing thereby protecting the 20 who were not infected of the original population of 1,000.

Harvard University experts say to reopen the United States by mid-May, the number of daily tests performed between now and then should be 500,000 to 700,000. So if population size is the factor California's share would be 7,200 tests a day.  While mid-May is perhaps overly optimistic, it actually appears California is getting there:

But we need to understand the goal for this level of testing. It is to measure our gains towards "herd immunity" through the spreading of the infection. This will be accomplished by letting people go back to doing their thing thereby contracting the disease. But not too many at a time. And while still trying to protect those most vulnerable to death.

Regarding Covid-19, California Governor Gavin Newsom has used the term to explain the levels of achieving a new normal. One reporter wrote:

    What does “herd immunity” look like in the age of COVID-19? Without a vaccine, about 28 million infected Californians.
    Based on current estimates, about 5 percent of infected people — or roughly 1.4 million Californians — would get severely ill. Of these, 840,000 could die, although there’s hope of holding that number down.
    This bleak strategy may be the only way through a pandemic that is causing profound economic, social and education paralysis. A vaccine, which also could provide herd immunity, is 12 to 18 months away, with likely additional months needed to scale up manufacturing and distribution.
    It’s also very scary. The governor’s promised “light at the end of the tunnel” could instead be the glaring halogens over an ICU bed.

The reporter is using a 70% HIT which if you look at the chart seems reasonable. If you extend those numbers to the entire US., it would mean 231 million Americans will have to get Covid-19 to create a national herd immunity. That would mean 11.6 million would get severely ill with as many as 7 million deaths.

But we don't even know if that will work.

Though people who recover from Covid-19 likely will have some degree of immunity for some period of time, the specifics are unknown. For instance, we don’t yet know why some who’ve been diagnosed as “fully recovered” from the virus have tested positive a second time after leaving quarantine. For instance, we don’t know why some recovered patients have low levels of antibodies.

 In fact there is much we don't know.

We don’t know today  how many people have been infected with Covid-19 and we have no way to estimate that number based on many years of experience like we do the flu. We don’t know the full range of symptoms. We don’t always know why some infections develop into fatal severe disease.

We don’t know what percentage of adults or what percentage of children are asymptomatic and don't know if we will ever be able to know. That is because we don’t know if the United States will ever be able to deploy the 22-million-people-per-day mass testing needed to develop reliable data before next outbreak of Covid-19. Heck, we don’t know when states will be able to test everyone who has symptoms.

We don't know how many virus particles it takes to launch an infection, how far the virus travels in outdoor spaces or in indoor settings (though experts now are saying 4 meters or 13 feet, not 6 feet), or if airborne movements affected the course of the pandemic.

We don’t know for certain if the virus will subside as the Northern Hemisphere enters the warmer months of spring and summer, as many other viruses do. And we don't know that whether it will return perhaps mutated in the fall or winter if it does subside, as many other viruses do.

Assuming a best case scenario we are at least 24 months away from achieving herd immunity with a vaccine. But we don’t know if or when researchers will develop a successful vaccine or whether the coronavirus will or already has mutated thwarting the future effectiveness of vaccines.

In order to give us time to gear up to treat victims, we have instituted the Great Economic Lockdown of 2020 which among other things includes insuring social distancing, also called “physical distancing,” which means keeping space between yourself and other people outside of your home. To practice social or physical distancing as prescribed:
  • Stay at least 6 feet (2 meters) from other people
  • Do not gather in groups
  • Stay out of crowded places and avoid mass gatherings
Note the words "at least" relative to the 6 feet (2 meters) measurement and again note that experts have discovered that the airborne movements of the virus seems to be 4 meters or 13 feet. So people are also being asked to wear masks.

Members of the pro-Trump right are opposing the Lockdown essentially saying that they have the right to choose how to protect their own safety while retaining all freedom of movement and association. As pictures appear of unmasked folks with guns standing next to each other demonstrating against the Great Economic Lockdown of 2020, one has to puzzle how they relate the Coronavirus Crisis to the common understanding of public safety - are they planning on shooting the virus if it doesn't turn itself in at a the police station?

There is a reason we frequently say "health and safety." They are not the same thing.

A difference exist between laws protecting public safety and regulations protecting public health. The protesters are confused as they don't understand the concept of a local or state government "Public Health Department" which is a government department authorized by law to use the science and art of preventing disease, prolonging life, and promoting health through organized efforts based on informed choices.

This is different from the concept of "Public Safety" departments like police departments which are the government departments authorized by law to use guns to enforce laws regarding criminal behavior. In general there is little commonality between the skills and expertise needed to handle public safety issues versus public health issues. It is police officers who use guns, not health officers.

The fact is that the ability to use a gun is a skill that in no way will protect you or your family from Covid-19. There are a growing number of families that include or included a police officer that will testify to that.

The one fact we know about the disease is that it is personal interaction between people, just socializing or engaging in business, is the human behavior that ultimately kills people. To not be free to interact with people for business or social purposes is contrary to everything Americans believe, except when the obvious result of the interaction will be to unintentionally kill human life.

The real problem is Americans under the age of 100 years old have never seen a worldwide pandemic from a virulent disease that seemingly randomly kills humans and against which no one has any immunity nor can obtain immunity from a vaccine. In fact only those of us older than age 65 can remember in the United States an epidemic such as polio. Fear of epidemics (a widespread occurrence of an infectious disease in a community at a particular time) and pandemics (an occurrence of an infectious disease over a whole country or the world) was once a part of human life.

Yes, annual influenza pandemics still kill people. In countries such as the United States vaccines though imperfect are available. Because the HIT for influenza is 33-44%, people frequently have some degree of immunity sometimes from prior year similar strains, Yes, deaths from the flu are normally limited to those who have prior unrelated health conditions which makes it seem similar to Covid-19 deaths. But one thing we do know is that a severe Covid-19 coronavirus infection looks nothing like influenza, not even the 1918 Spanish Flu. We do know that Covid-19 attacks the lungs and blood vessels in ways unlike the flu.

Just exactly how much risk are we willing to take to reopen our economy and society to personal interaction? Having had no similar experience, we don’t know how to open things up again, What if the actual safe social distance is 13 feet, not six?

We could, of course, create herd immunity by just ending all restrictions. But we in California quite literally have set a goal to reduce restrictions in order to infect the most people possible while avoiding high hospitalization and death rates.

Last Tuesday Governor Newsom said at his  news briefing: "There's no light switch here. It's more like a dimmer. That dimmer is this toggling back and forth between more restrictive and less restrictive measures."

Make no mistake about it. Ending the Great Economic Lockdown of 2020 will not end the Coronavirus Crisis of 2020. We will discover when we've ended a specific restriction too soon by the level of jumps in hospitalizations and deaths.

With that said, I trust Newsom's approach. And because I know most of them know how to do math, I also trust the group of people he has appointed to his Task Force on Business and Jobs Recovery (see below) to help California thread the needle required to stitch our economy back together while minimizing deaths.

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