Since the COVID-19 pandemic began, there has been a steady and persistent onslaught of new variants of concern that has challenged both natural and vaccine-acquired immunity. From the original SARS-CoV2 virus to the alpha, delta and omicron variants, the rise (and fall) of cases have been driven by the emergence of each new variant.
Most people are not interested in such epidemiological data. What everyone cares about is staying healthy and for some, infection free.
Easier said than done.
The virus has run rampant across the nation. As of late July, the White House estimated that more than 70 percent of the population had been infected. As such, the more appropriate objective now for most should be to not get reinfected.
Yet, to achieve this objective requires an examination of the variants that are circulating and infecting people.
Over the past two months, the omicron subvariant BA.5 has been dominant, supplanting the BA.4 and BA.2.12.1 variants as the primary circulating variant. Most recently, the BA.4.6 variant has begun to establish itself, growing its presence among confirmed cases as the dominance of BA.5 begins to level off. What remains open is whether other variants, like BA.2.75, eventually overtakes them all.
The challenge with every new variant is that they each possess their own unique characteristics. The vaccines available were developed around the original virus. In spite of its mismatch to all the variants since then, including omicron, it has held up surprisingly well to limit deaths, while providing limited protection against infection. Hospitalizations have inched higher with the BA.5 variant, even among people who are vaccinated, although not like what was seen with previous variants when fewer people were vaccinated.
This fall, a new bi-valent vaccine will be available containing both the original virus and an early omicron variant, BA.1. The effectiveness of this vaccine against not only severe disease in the population, but infections, remains to be seen. Clinical trials results have been sufficiently promising to prompt the United Kingdom to authorize its use.
The United States government has purchased 66 million doses of a bivalent vaccine that targets the BA.4 and BA.5 omicron variants. The White House has indicated that such vaccines will be available by mid-September.
The challenge with omicron variant-specific vaccines is that the dominant circulating variant today will almost certainly not be the dominant circulating variant in three months. Any new vaccines are certain to always be playing catch-up and not have a direct match. This is similar to how influenza strains must be selected for influenza vaccines as much as nine months in advance.
What is not needed is an omicron-specific vaccine but a pan-coronavirus vaccine. Such a vaccine would offer protection against multiple variants, which would extend the time span across which such vaccines would provide protection and reduce the need for frequent boosters, which the current vaccines require.
Research is underway to develop pan-coronavirus vaccines. The Coalition for Epidemic Preparedness Innovation and the National Institutes of Health (NIH) are investing a significant amount of funds to support such efforts. When such products will become available remains uncertain. However, such efforts are critical to move vaccination efforts to a higher level of population protection.
As people continue to be infected, no matter how benign the cases may be, new variants will emerge. In general, as a virus becomes more contagious and spreads more easily, conventional wisdom suggests that the disease it produces tends to become less severe. The rationale for this is that if a virus becomes more virulent and kills its host, then the virus cannot spread as easily as the hosts rapidly die off. This is basic epidemiology, although scientists have challenged this theory.
Hopefully, this trend will be displayed with each new omicron variant. Of course, this does not take into account any long-term effects of infections, like long-COVID and a higher risk of heart disease.
Tracking COVID-19 virus variant and subvariant trends is a necessary epidemiological exercise to observe the status and properties of the circulating virus. As the new Centers for Disease Control and Prevention (CDC) COVID-19 policy places greater responsibility on individuals to protect themselves based on their personal risk, variant tracking becomes even more critical.
Data can provide useful information, and information can help everyone stay as safe as they choose to be and want to be.
Sheldon H. Jacobson, Ph.D., is a founder professor of computer science at the Carle Illinois College of Medicine at the University of Illinois Urbana Champaign. With a background in risk-based analytics and data science, he applies his expertise in data-driven risk-based decision-making to evaluate and inform public policy.