From Pandemic to Endemic: Will the Omicron Variant Turn COVID-19 into a Seasonal Flu Next Winter?
And just like that…the Omicron Variant exploded on the world, slamming the US right over the holidays, quadrupling the number of new COVID cases over a three-week period, with currently more than five million new cases reported per week. Healthcare systems, which were already dealing with overworked staff from twenty straight months of over-utilization, were also faced with vaccine mandates that simultaneously reduced their workforce. As a result, hospitals struggled to staff the necessary patient beds for the more than doubling of COVID hospitalizations.
How did this happen when the vaccination rate in the US is almost 80%? According to the CDC “Current vaccines are expected to protect against severe illness, hospitalizations, and deaths due to infection with the Omicron variant. However, breakthrough infections in people who are fully vaccinated are likely to occur.”
As dire as the current situation is, there is reason for cautious optimism. The Omicron Variant has proven, at least in its early stages, to be far less lethal than the original COVID virus (known as COVID wildtype) or its other variants. This is just an example of the process of natural selection. A more contagious variant that carries mild disease has a competitive advantage over other variants because those people with the less severe variant are more likely to be asymptomatic for a longer period and less likely to quarantine or seek medical care.
The mortality rate from COVID-19 had already been steadily declining over time before the Omicron Variant, due to cohort effects, vaccinations, and the development of improved COVID anti-viral treatments. At this point the Omicron Variant appears to be approaching the mortality rate of the seasonal Flu, which is just a small fraction of 1%.
If COVID-19 becomes more like the seasonal Flu, then what? Again, according to the CDC, there were 35 million Flu related cases and 16 million medical visits and 20,000 Flu related deaths during the 2019-2020 Flu season. Before the Omicron Variant emerged, the COVID-19 case numbers were trending towards a recurrent case load of that same magnitude for the 2022-2023 Flu Season. Manufacturers of Flu vaccines, such as Moderna, Sanofi-Pasteur and GSK are already testing the efficacy of combination Flu-COVID-19 vaccines. It is likely that COVID-19 boosters, coupled with quadrivalent High Dose Flu vaccines, will become the standard of care for treating the over-65 population.
As promising as these developments may seem, it is important to remember that the vaccine effectiveness (VE) of Flu vaccines has declined in the last ten years from approximately 60% to 40%. It is too soon to tell that the vaccine effectiveness for the COVID-19 vaccine was over the 2021-2022 season, but the Omicron variant appeared to be one which was able to reinfect previous COVID-19 patients as well as vaccinated and boosted patients. It’s likely that further mutation caused by antigenic drift of the Omicron variant would also depress the vaccine effectiveness rates of the combined FLU/COVID vaccines. The probability of an emerging combined Flu-COVID variant remains unknown and could further reduce effectiveness of both vaccines.
As a “base-case” scenario for COVID-19 over the 2022-2023 Flu season, this would imply an incidence of 30-40 million COVID-19 Cases and a vaccine effectiveness rate of only around 25%-30%. If the mortality rate continues to decline, then the number of COVID-19 related deaths would be far less than the current 80,000 deaths that have occurred in the US since November 1st, 2021.
For planning purposes, this still means that healthcare system must literally redouble their capacity in terms of dealing with the seasonal peak load of respiratory cases. Healthcare systems must also resolve the issue of non-COVID patients delaying diagnostic tests or screening during Flu season.
For all other businesses, every year from now on is going to be a severe Flu season. Disruptions to businesses outside of healthcare will be minor for most sectors when compared to those of the last two years, but the lingering impact of COVID will impact the travel and hospitality industries during the winter months for several years. There are other planning scenarios for COVID that may be more or less severe in nature, but this baseline scenario is one which can be an anchor point for strategic planning for the next two years.