Covid-19 Refined

Early in the pandemic our understanding of Covid-19 was necessarily based on analogies to similar diseases. Influenza was the commonest comparison. For months that comparison encouraged us to believe (or at least hope) that people with Covid-19, like flu, didn’t transmit virus until they had at least some early symptoms. Folks like the Rush Limbaugh and Mr. Trump declared, based on wishful thinking, that Covid-19 was no worse than the flu and, like the flu, would just go away with warmer weather. 

Understanding of Covid-19 is gradually building as our experience broadens and information is shared. As is the way with science, no single study is gospel, but many studies, each carefully scrutinized and all considered together, are sharpening our understanding of what we face with this disease. 

Even the sober wing of the Republican Party understands Covid-19 is not the flu. The Wall Street Journal on July 21 published an article (hidden behind a paywall), “How Deadly Is Covid-19? Researchers Are Getting Closer to an Answer.” The authors assembled the results of a number of large studies and came up with some numbers to which we should all pay attention. Much of their information came from the CDC’s Pandemic Planning Scenarios webpage (which is not hidden and was updated July 10)

The current best estimates based on multiple, worldwide studies is that Covid-19 kills one person for every 150 it infects (Infection Fatality Rate [IFR] of 0.0065). The denominator of this IFR is inflated by the estimated 40% of people who are infected (judged by antibody evidence) but never are symptomatic, even though they can transmit the virus. Best estimates of seasonal flu mortality are 1 in 900, one sixth of Covid’s IFR (and would be even smaller if the flu mortality estimate included entirely asymptomatic cases–which it does not). Rush Limbaugh, Sean Hannity, Laura Ingraham, and Donald Trump were and are ignorant, opinionated fools to declare Covid-19 to be no more worrisome than the flu.

Of course, the risk of death from Covid-19 varies with age, medical condition, available medical care, and other factors. For those of us over the age of 65, the risk of death, once infected, is about one in twenty (5.6%) Is there any activity in which you would willingly take part in which the advertised risk of being killed is one in twenty? [See P.S. below] I’ve taken part in quite a number of physically risky ventures in the course of my life, but none of them carries a one in twenty risk of death,

These Infection Fatality Ratios consider mortality, not morbidity: respiratory compromise, chronic fatigue,  and multiple other long term sequelae of infection, sequelae that weaken but don’t kill. Republicans, even Trump supporters and their families, are not immune to the reality of Covid-19 infection. Herman Cain, age 74, former presidential candidate and recent mask-dissing attendee of Trump’s Tulsa rally has been hospitalized and on oxygen for nearly four weeks with Covid-19.  (The day after I composed this email Herman Cain died.)

Other truths about this virus are also coming into focus. A Spokane teenager of my acquaintance and her friend recently lost their sense of taste and smell on the same day, one week after their only plausible exposure to Covid-19. They and two others had spent time (some of it indoors) in the company of a third friend whose brother came down with symptoms and tested positive after their time together. The friend, the only link and the only plausible carrier with whom they’d had contact, never personally manifested symptoms andtested negative for the virus twice following their contact. Fortunately, my teenage acquaintance suffered only a mild case, regained her sense of taste and smell in about a week and, with careful quarantining, did not infect her family. The other young woman had a rougher course, but recovered without experiencing pneumonia. Both young women tested positive for the virus.

The take-home from this anecdote and published data is that Covid-19 can be caught from symptomatic, pre-symptomatic, and asymptomatic people infected with the disease. One best assume that everyone with whom one comes in contact may be shedding virus. Influenza is far less contagious. Viral shedding with influenza virus mostly does not occur in the absence of early symptoms of the disease. In the current world population Covid-19 is not the flu. Covid-19 is more transmissible, more deadly, and productive of greater morbidity than influenza.

Keep to the high ground,

P.S. Unless an effective vaccine becomes widely available, the death toll from Covid-19 is probably just getting started. The following is mathematical conjecture, but, if you take the death rate of 5.6% (1 in 20) in the over age 65 cohort in the U.S. population (these over age 65 are 13% of the whole U.S. population of 330M), an IFR of 0.0065 (1 in 150) in the whole population, and assume herd immunity when 60% of the population has been infected and made antibodies, then in the U.S. alone we would see 1.44M dead overall, nearly ten times what we’ve seen so far. 1.29M of the dead would be from the over 65 yo cohort, but 212,000 of the dead  would be among working age and younger U.S. residents.

Since the greatest viral transmission occurs indoors, I predict the coming winter will be long, dark, cold, and isolated, especially for those over 65. We had better hope for a safe and effective vaccine. The earliest that could happen now appears to be early in 2021. Cross your fingers.