Estimating rise, fall of virus tough task
er to forecast this wave’s timeline.
This surge is moving slower than previous ones
One major difference between this surge and previous surges is that it is moving a lot slower, said John Swartzberg, an infectious disease expert at the UC Berkeley school of public health. That means, even though cases keep rising, we are not seeing them spike rapidly like we have in the past — making it more difficult to discern when the peak might come.
“There’s been an increase, but it’s just not been dramatic,” he said. “We just don’t perceive it the same way as we see when something shoots up. The human psyche just doesn’t work when things are subtle like that.”
Omicron seems to be spinning off more subvariants
This wave is also different in that omicron has spun off several subvariants, which we have not seen before.
While part of that is likely a “phenomenon of how much better or more sophisticated our diagnostics have become,” Swartzberg said, allowing us to tease out these different subvariants in a way we could not before, it could also be a result of omicron being a quickerchanging, less-stable variant.
“There may be more going on ... it may be that this particular variant, omicron BA.1, has more plasticity and is able to change in ways that it can evolve very quickly into newer and more transmissible variants and subvariants,” he said — noting that anything beyond the difference in diagnostics is conjecture.
Lockdowns have decreased globally
The decline of pandemic restrictions on movement and travel means surges are more likely to happen simultaneously on a national level, experts said, making the situation more complex and fluid.
“People are kind of all over the place,” said Dr. Peter ChinHong, an infectious disease expert at UCSF. “So even previously careful people are not feeling as careful anymore because the world is reopened and people want to re-engage with life, but it also involves movement of people.”
While he emphasized that
greater mobility alone isn’t driving the ongoing swell of cases, it does complicate how well we can predict it.
We don’t yet know how long natural immunity protects people
Another thing complicating the behavior of this surge is that so many people have gotten it, and we don’t know exactly how long natural immunity lasts, especially in milder cases, Chin-Hong said.
“We have a lot of different exposures to different flavors of virus, and different timing of different exposures to different flavors of virus,” he said. “Natural
immunity is sort of a wrench right now in prediction models.”
He noted that we also don’t yet know how vaccinations, boosters and natural immunity interact with new variants and subvariants in terms of slowing transmission — though vaccinations and boosters are still very effective at protecting people from severe disease and death.
COVID is a new disease, and much is still unknown
COVID-19’s existence so far is just a blip relative to the history of diseases, Swartzberg noted — so we still have much
to learn.
“Maybe we just don’t yet have a really good understanding of how this virus behaves in the human population after just two years and three months,” Swartzberg said.
“I think we have to have enormous humility in terms of making proclamations about what we think is going to happen in the immediate future with this virus,” he added. “I just don’t think we know.”