“Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.” - John Quincy Adams
“All great achievements require time.” - Maya Angelou
In November 2020, Dr. Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization (WHO), said: “We might be tired of COVID-19. But it is not tired of us.” Unfortunately, this statement is proving to be all too true. Just last week, more evidence of COVID-19’s tenacity emerged when
the global death toll of COVID-19 surpassed 4 million;
Japan declared a new state of emergency over a rise in cases and cancelled attendance of all spectators at the upcoming Olympics;
Delta became the dominant virus in the U.S.; and
the Center for Disease Control and Prevention (CDC) confirmed that COVID case numbers were rising.
Therefore I thought that this might be a good time to take stock of the wearing battle with SARS-CoV-2 and ask, “What is the endgame of the COVID-19 pandemic?”
Potential endgame scenarios. Pandemics can end in different ways. In a 1999 article in the CDC’s Morbidity and Mortality Weekly Reports, Walter R. Dowdle, an eminent CDC virologist, provided these definitions of potential outcomes of responses to pandemics:
Control: The reduction of disease incidence, prevalence, morbidity or mortality to a locally acceptable level as a result of deliberate efforts; continued intervention measures are required to maintain the reduction. Example: diarrheal diseases.
Elimination of infections: Reduction to zero of the incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts; continued measures to prevent re-establishment of transmission are required. Example: measles, poliomyelitis.
Eradication: Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed. Example: smallpox.
Extinction: The specific infectious agent no longer exists in nature or in the laboratory. Example: none.
None of these scenarios reflects where things currently stand in the battle against SARS-CoV-2. We would all like to see the eradication if not the extinction of SARS-CoV-2. But as was noted by Dowdle, the extinction of an infectious agent has never been achieved, and there is only one example of eradication of an infection in humans—smallpox. (It’s a little nerve-wracking to realize that samples of variola, the virus that causes smallpox, are stored in highly secured containment laboratories at the CDC and Russia's State Research Center of Virology, so it’s not considered extinct.)
In my view, the eradication of smallpox is the most notable and profound public health success in history. In the case of eradicating smallpox, vaccination was key. Starting with Edward Jenner’s vaccination using scrapings from cowpox lesions of milkmaids in 1796, an incredible global collaboration evolved over the course of the next two centuries. And, as I discussed in my September 23, 2020 Germ Gem post “Smallpox Is Gone, but the Lessons Learned Live On,” the WHO played a pivotal role. In 1980, the WHO issued a declaration that smallpox was eradicated.
COVID-19 in perspective. The battle against SARS-CoV-2 isn’t our only ongoing altercation with a microbe. There are approximately 1,400 known species of human pathogens, including viruses, bacteria, archaea, fungi, and parasites. I like to emphasize that a vast majority of germs are our “intimate friends,” many of which we humans depend upon. Nonetheless, the fact is some are our “mortal enemies,” that is, they are pathogens that make us sick, and in some cases, do us in. It’s important for us to keep in mind that some of these pathogens are every bit as, or even more, threatening than SARS-CoV-2.
When it comes to confronting the global spread of infections, that is, pandemics, we’ve come to depend upon the WHO. At its inception in 1948, the WHO prioritized malaria as a disease to eradicate. It soon became clear, however, that this just wasn’t possible. So instead, the WHO, along with other public health organizations, worked on elimination of this devastating parasitic infection mainly through measures that control the mosquito vector as there is no effective vaccine. Since 2000, the WHO has designated 25 countries as malaria free, that is, malaria has been eliminated within these countries. Nonetheless, this deadly disease is still responsible for approximately 1-3 million deaths per year with the overwhelming majority of these deaths in children aged 5 years or younger.
Along with malaria, HIV/AIDS and tuberculosis (TB) are often regarded “The Big Three” pandemics. Almost 1 million people die of HIV/AIDS per year, and TB kills an estimated 1.5 million people annually. Both of these pandemics are targeted for elimination by 2030.
Can COVID-19 be eliminated? In a July 8, 2021 article in the Journal of the American Medical Association, “Potential COVID-19 Endgame Scenarios: Eradication, Elimination, Cohabitation, or Conflagration?,” an argument is made for a “civil cohabitation” with SARS-CoV-2. As the authors point out, eradication of SARS-CoV-2 isn’t feasible, in part because unlike the smallpox and polio viruses, SARS-CoV-2 has an animal reservoir (bats, mink, and possibly other heretofore unrecognized species). While I agree with the authors, I find their concept of civil cohabitation rather vague.
In my opinion the endgame of the battle against COVID-19 should be its elimination. After all, if this goal already has been achieved with malaria, and it is a viable target for HIV/AIDS and TB, then eliminating COVID-19 seems eminently doable. Achieving this objective, however, depends upon three factors that ultimately led to the eradication of smallpox: vaccination, resolve, and leadership.
As you’ve read in several previous Germ Gems posts, achieving herd immunity, either through vaccination or natural infection, is essential for elimination of SARS-CoV-2. Herd immunity, currently pegged at about 60% to 80%, is a moving target. It is partly dependent on a virus' basic reproduction number, R0 (pronounced R naught), a measure of contagiousness or transmissibility. R0 represents the number of secondary infections resulting when one infection is introduced into a completely susceptible population. R0 for SARS-CoV-2 is estimated to be 2.5 (range 1.8–3.6).
We’ve seen just how contagious this coronavirus can be, especially when the Delta variant is introduced into a community. Nonetheless, when compared to measles virus, SARS-CoV-2 is not as challenging. (For measles, R0 is often cited to be 12–18, which means that each person with measles would, on average, infect 12–18 other people in a totally susceptible population.) And measles is a viral infection that’s been eliminated by vaccination.
For insight into the importance of resolve (dogged determination) and effective leadership in winning not just a battle but a war against a virus, I recommend reading one of any number of books on the history of smallpox eradication. By comparison to smallpox, we are in the very early stages of the battle against COVID-19. But thanks to science and public-private partnerships between government and the pharmaceutical industry, we have highly effective and safe vaccines to fight this virus.
Finally, I believe the leadership needed to eliminate COVID-19 is in place at the WHO, CDC, National Institutes of Health, and other nonprofit organizations, as well as private companies, to blow SARS-CoV-2, if not completely out of the water, then to a place where it can no longer terrorize humanity. As time goes on, this may require boosters or other vaccine strategies. Nonetheless, I believe we’ve seen that the scientific and public health communities along with partners in government and the private sector are up to this challenge. This virus can be eliminated. In the words of General George S. Patton, “Wars may be fought with weapons, but they are won by men. It is the spirit of men who follow and of the man who leads that gains the victory.”