By Mark Van Sumeren
April 4, 2022 – Health officials report that BA.2 has overtaken BA.1 as the dominant strain of the SARS-CoV-2 virus in the United States. This strain led to infection surges across Europe and the Asia-Pacific region. So, BA.2’s emergence in the U.S. begs whether we should anticipate a Covid resurgence here?
Already, we find evidence that infections could rise in this country following more than two months of decline. Yet, low current infection rates and significant immunity protection could limit the intensity and severity of any infection resurgence.
Throughout March, BA.2’s circulation placed Europe and Asia Pacific countries at the epicenter of Covid infections. In most Asia-Pacific countries, these infections fractured long-standing containment efforts. Many countries suffered infection rates higher than ever reported among their citizens.
European countries encountered a BA.2 surge too, although with crucial differences. This surge followed several earlier ones, including the BA.1 surge earlier this year. Unlike Asia Pacific countries, Europe faced the BA.1 surge with the benefit of (limited) immunity from prior Covid infections. Already, infections are declining without reaching the peak levels posted earlier this year. Thus, the intensity and severity of the BA.2 surge failed to match that of the BA.1 wave.
Case rates fell in the United States for more than two months, beginning in the middle of January. During this time, cases fell nearly 30x. However, cases increased in seventeen states last week, including heavily populated Florida, Illinois, Massachusetts, New York, and New Jersey. Nationwide, new cases remained flat over the past eight days.
At least a few observers, including Drs. Fauci and Topol opine that a BA.2 wave has already launched in these states and will spread soon across the country. However, they expect any surge will be mild compared to prior waves. These observers anticipate that our experience will parallel Europe in many regards. Topol credits the relatively low case rates in mid-March, suggesting BA.2 infections should peak below BA.1.
Early evidence hints of low severity of a BA.2 wave as well. In thirteen states reporting increased cases last week, fewer patients required hospitalization than a week earlier. Even in those states that admitted more patients last week, the increase failed to match the rate of new cases.
The possibility remains that this lower hospitalization experience reflects infections occurring among younger, healthier persons early in a new wave. However, recent data from New York state shows hospitalizations declining even on an age-adjusted basis.
A recent ensemble forecast downplays any expected infection resurgence in the United States. New cases remain steady for at least the next three weeks in this model published last week.
As we wait to observe how any BA.2 wave materializes, the current Covid situation continues to improve. The Centers for Disease Control and Prevention (CDC) rates most communities in the U.S. as “Low” (95%) or “Medium” (4.5%) for Covid transmission and hospital impact. These ratings have improved every week since the CDC introduced this Community Level rating system five weeks ago.
Only seventeen communities nationwide rate “High”, down from 53 a week ago.
Further, Covid’s impact on our healthcare system eased again last week. Fewer Covid patients required hospitalization last week than at any time since the early days of the pandemic. These patients occupied only one of every twenty-six inpatient beds last week. Just one month ago, Covid treatments required one of every seven beds.
Lastly, fewer people died with Covid for the eighth consecutive week and less than any time since last August. The ensemble forecast envisions another 50% decline in Covid deaths in the next three weeks.