Endemic ≠ Benign

 

“There is a widespread, rosy misconception that viruses evolve over time to become more benign. This is not the case: there is no predestined evolutionary outcome for a virus to become more benign, especially ones, such as SARS-CoV-2, in which most transmission happens before the virus causes severe disease…”

Aris Katzourakis
Professor of Evolution and Genomics
University of Oxford

 

I typically don’t like to post on a non-psychiatric topic immediately after posting one.  But the current level of misinformation on the pandemic necessitates this. That is obviously not because I am a big influencer with widespread readership – but I like responding to the sea of right wing misinformation on Twitter. And today it was all about how the response to the pandemic was an overreaction with far reaching effects. Nothing about how the virus has killed 1.1 million Americans, the impact of that mortality on families and businesses, the impact on the healthcare system and its workers, and the enduring disability of millions with long COVID.  The evidence is clear that the pandemic was mishandled early on as the Trump administration denied the degree of the problem and then falsely reassured the public that everything was under control. The only way the right wing can rewrite that history is to push a false narrative that there was a conspiracy theory to prevent any investigation of the lab leak theory, that face masks and public health measures don’t work, that school children are irrevocably damaged from online learning, and that all of these unnecessary measures were really an unnecessary infringement on freedom. Unfortunately, pandemic viruses don’t work that way. They do not really care about your political affiliation or what you read on Twitter.

One of the popular myths during the early to mid-pandemic was the idea of herd immunity and how by ignoring all of the public health suggestions up to and including the immunizations (or “jabs” as they are referred to by the right wing) the entire population would build up immunity and the pandemic would fade away. The way that argument was typically presented minimized any death or disability along the way.  Herd immunity would happen and it would happen quickly to resolve the problem.  It also implicitly assumed that writing off the elderly and the 10% of the population that is immunocompromised was morally acceptable.  Not much discussion of how herd immunity would happen without immunizations – since many of the proponents were ideologically sympathetic to the idea that public health measures and immunization were unnecessary.

An associated concept of endemic disease cropped up at one point. The popular usage was  to say: “This is no longer a pandemic, there are no more large outbreaks, therefore we can declare it is an endemic like the common cold viruses.”  Since this was also an ideological rather than scientific argument – it was also a rationale for stopping all of the suggested public health measures and getting things back to normal as soon as possible,

That brings me to a brief essay on endemics written by evolutionary virologist Aris Koutzourakis in Nature (1).  The title speaks for itself.  His definition of endemic is straightforward -  endemic infections mean that the infection rate is static – not rising or falling. The best intuitive example is common cold viruses – there are predictable seasonal fluctuations but the number of viruses and the composition of the pool of common respiratory viruses stays about the same and no one outcompetes the others. Nobody is too worried about common cold viruses because they are not too deadly and don’t commonly overwhelm the healthcare system.  Influenza viruses are somewhat different.  Whether and epidemic or pandemic occurs depends on an elaborate system of guessing the correct components for the influenza vaccine and measures taken to prevent zoonotic transmission of potentially more lethal influenzas viruses – like avian influenza. That backdrop of common cold versus influenza viruses seems like a way to understand endemicity.  It leaves out one important point and that is endemic pathogens can also be lethal and create disability.

Dr. Koutzourakis lists several examples of endemic, but lethal pathogens including malaria, polio, and tuberculosis.  They are all significant causes of mortality and morbidity.  He successfully predicted that unless the pandemic was stopped quickly subsequent evolving variants could be more transmissible and difficult to treat.  That occurred with the subsequent 4 SARS-CoV-2 variants. Viral evolution has also been observed with other pandemic viruses and the occurrence of more dangerous variants. He analyzes the current behavioral situation correctly in the United States.  Even if people are not using the word endemic – they are generally stating that the pandemic is over and that it is time for a return to normal.  Normal typically means no public health measures like masking, social distancing, or even deciding to stay home if you are ill.  The only place that those measures are acceptable is in a medical or dental facility and even then they are no longer universal. To compound the problem, the anti-public health ideologues are either bragging that they were correct all along or actively spreading misinformation about masks, vaccines, or the origin of the virus.

The graphic at the top of this page (click to enlarge) is taken from the CDC web site today.  Even though the area in the red rectangle looks fairly static going back to May of 2022 – the actual number of cases per week ranges from 170 to 900K.  That corresponds with weekly deaths 1,795 to 3,697.   Dr. Katzourakis suggests that there is the potential to see additional spikes of infection and suggests that the direction this pandemic will take at this point depends a lot on continued public health measures, immunizations, antiviral medication, and individual behavior.  One of the critical aspects of science as I explained in my previous post is that scientists look at data supporting or refuting hypotheses in terms of probabilities and also speculate with probability statements. Viral epidemiologists and evolutionary virologists know how viruses work and evolve. Their predictions are much more likely to be accurate than someone with no expertise and no data.  The next time you hear politicians or news personalities talking like this pandemic is over take it as an unfounded opinion. Do the same thing when your neighbor tells you that you don’t need to get any more vaccinations or wear a mask in crowded places.

Don’t let ideology blind you to science.

 

George Dawson, MD, DFAPA

 

References:

1:  Katzourakis A. COVID-19: endemic doesn't mean harmless. Nature. 2022 Jan;601(7894):485. doi: 10.1038/d41586-022-00155-x. PMID: 35075305.

2:  Centers for Disease Control and Prevention. COVID Data Tracker. Atlanta, GA: US Department of Health and Human Services, CDC; 2023, March 12. https://covid.cdc.gov/covid-data-tracker  accessed on 03/12/2023

3:  Callaway E. Beyond Omicron: what's next for COVID's viral evolution. Nature. 2021 Dec;600(7888):204-207. doi: 10.1038/d41586-021-03619-8. PMID: 34876665.