Still, the testing shortage doesn’t appear to be the only reason cases haven’t risen in the United States. Hospitalization trends for Covid generally only lag case trends by about a week. And hospitalizations continued to fall in the United States, to their lowest level in more than two years.
Even though high levels of immunity have kept cases from rising so far, the effect may not be permanent. Remember: about 45% of Americans have been infected with Omicron, leaving about 55% who were not. While many of those 55% may have had an earlier version of Covid, immunity may decline over time.
The current moment could be one of those times when we wonder why cases haven’t started to rise just when they are starting to rise. “It may be too early to see a signal,” Brown University epidemiologist Jennifer Nuzzo told me.
4. Another Mystery
Throughout the pandemic, Osterholm — the Minnesota epidemiologist — lamented that many scientists, journalists, and laypeople are exaggerating what we actually know about Covid. His favorite example: the Alpha variant swept through Michigan and Minnesota last year, then largely died out, without causing a rise in cases in other parts of the United States. Another example: BA.2 has recently become the dominant variant in India, South Africa and other countries. countries without causing a spike in cases.
When I called Osterholm yesterday to ask why cases hadn’t increased over the past few weeks, he simply said, ‘I don’t know, and I don’t think anyone really does.
Of all the variants, only the original Omicron was so contagious that it spread around the world in predictable ways, he said. Other versions of the virus have risen and fallen in mysterious ways, much like a forest fire can go out without burning an entire forest.
The bottom line: Cases still look likely to rise, possibly significantly, in the United States soon. But a new wave seems less certain than a few weeks ago. Either way, the steps that can save lives in the coming months remain the same: more vaccines, including boosters; and greater awareness of available treatments that offer additional protection to vulnerable people.