WJohn Dennehy and his colleagues from the Biology Department in the borough of Queens do not know exactly what has happened in the New York sewers over the past two years. One thing is clear: the pandemic has produced a lot of new and unknown things here. New Sars-CoV-2 strains that had not yet been described were romping regarding in the wastewater. Between January and June 2021, Dennehy and his team took samples every two weeks. They had been sent underground as outposts following the first, devastating wave of infections. It was now known that the face of the pandemic virus, which had spread from Wuhan, China, to the east and west coasts of the United States the year before, had long since changed. New variants with a dozen mutations and significantly different properties—higher infectivity, faster replication—had arisen and spread in different places: alpha, beta, gamma, delta, epsilon, kappa. The world had pricked up its ears, even the virologists were surprised by the astonishing evolutionary “drive”, the ability to change, of the corona virus.
Kryptische Virenlinien
Dennehy and his colleagues didn’t have to look far for anything unusual either. In the wastewater samples, they used their molecular filters to fish out countless gene snippets that might clearly be assigned to the RNA virus first described in Wuhan and then once more not. Although many mutations had become known in patients in the New York Covid clinics following the sequence analyzes that had been carried out more and more in the meantime, there remained a residue that the researchers called “cryptic virus lines”. Laboratory tests designed to examine the function of the unusual gene sequences showed that the coronavirus had obviously greatly expanded its host range in the first year of the pandemic: With the modified spike proteins on the surface, it might not only infect cells from humans, but also from other cells infest rats and mice.
In addition, mutations were discovered that occur in the omicron variant, which was only described many months later and is now dominant. Laboratory viruses equipped with the appropriate surface molecules – so-called pseudoviruses – were resistant to antibodies. A large number of completely mysterious gene snippets whose properties have not yet been clarified were also found and described in the wastewater samples. Whether they come from a previously unknown animal reservoir or from Covid-19 patients whose viruses had fallen through the inevitably incomplete sequencing grid – it also remains unanswered in the evaluation that the New York biologists have now published in the journal “Nature Communications” was submitted.