Coronavirus infections are on the rise across Houston, wastewater tracking shows, even as fewer people seek testing two years into the pandemic.
Four months after the city saw record infection rates caused by the highly contagious omicron variant, new COVID-19 cases are once again climbing, according to data collected by Rice University and the Houston Health Department. The most recent sewage samples show increased viral loads at all but a few of the city’s three dozen wastewater treatment plants.
Citywide, the amount of virus particles detected in wastewater is up 242 percent above baseline, with an overall positivity rate of 14 percent. Both metrics increased by about a third over the previous samples, taken in early May. At the 69th street plant, serving much of the Inner Loop, officials said virus levels are 123 percent above baseline, with a 22 percent positivity rate.
Despite the uptick, health officials do not anticipate raising Harris County’s threat level to the highest level. The county’s threat level is currently set at moderate, signally a controlled level of COVID spread.
“Even though we see positivity rates going up, our hospital rates continue to remain low, said Dr. Erika Brown of the Harris County Health Department.
New of the rise in viral levels in the wastewater comes days after researchers at Houston Methodist reported new insight into how the omicron variant is mutating in Houston and across Texas.
Researchers demonstrated that two dominant sublineages of omicron have developed “unprecedented numbers” of spike protein mutations, leading to increased transmissibility. The mutations also enhance its ability to evade vaccines and the immune system.
This is a press release about the study in question; it’s from late April, which I’d classify as more than “days” ago, but whatever. The COVID levels in our wastewater continue to rise, but if the hospitals are still not seeing an increase in patients, then the threat level will stay where it is. I don’t know how long we can maintain this balance, but I sure hope it continues.
That press release is worth a read:
“One of the surprising findings in this study was that many mutations with critical roles in immune escape in previous variants of SARS-CoV-2 do not play the same roles in immune escape in omicron, and, in some cases, the effects of these mutations are completely reversed,” said Gollihar, who is the head of antibody discovery and accelerated protein therapeutics in Houston Methodist’s Center for Infectious Diseases. “The virus also appears to be stabilizing itself to allow for more mutations to evade our immune systems.”
He said this study is the first to systematically dissect each of the omicron mutations across the entirety of the spike protein. Previous studies miss contextual and long-range interactions across the protein.
“We developed a comprehensive map showing various mechanisms of immune escape by omicron that allows us to identify which antibodies retain neutralization activity against the virus,” Gollihar said. “This and future work will enable clinicians to make informed decisions about the use of monoclonal antibody therapy and aid in the development of next-generation vaccines.”
Having this new information about key features of omicron’s spike protein mutations and how they synergize, Gollihar and his team say it’s possible that the continuing accumulation of mutations may set the stage for greatly altering the equilibrium and stability of the spike protein in a way that allows for new, more virulent strains to develop. Understanding this evolution is critical, they say, to better inform future therapeutic targets and vaccine formulations, as the SARS-CoV-2 virus will continue to evolve with new variants inevitably arising and spreading.
Looking forward, they add, the strategy used in this study also will be applicable to future zoonotic outbreaks and other microbial pathogens, providing a powerful platform for investigating evolutionary trajectories of infectious agents and engineering appropriate and adaptable vaccines.
“We will continue to monitor the virus for changes in the spike protein and add new antibodies to test as they are discovered. Continuing to do so will allow us to design better probes for antibody discovery in hopes of engineering new therapeutics by finding potent neutralizing antibodies across all variants,” Gollihar said. “We have also recently expanded the platform to other pathogens where we hope to stay ahead of other potential outbreaks.”
I’m in awe of the work these folks have done and continue to do – I’m speaking of the researchers worldwide, not just these specific ones. We’re in a constant race with this virus, and so far we’ve been able to keep up. As above, I sure hope that continues, too. Stace has more.