LONDON – While the rest of the world is trying to eliminate the Covid-19 Delta variant, British researchers are advancing in the cultivation of a carefully controlled batch in a laboratory they hope to use to infect volunteers in the studies.
The effort marks a new phase in the UK’s human challenge trials, the only Covid-19 studies in the world that intentionally expose participants to the virus with the aim of developing new vaccines and treatments. Other researchers also isolate and grow specimens of Covid variants for study. U.S. government-funded scientists are producing variants for research, but not for use in humans, an official at the National Institute of Allergy and Infectious Diseases said.
Two Covid challenge trials sponsored by Imperial College London and Oxford University began earlier this year in the UK. So far they have exhibited more than 40 young healthy volunteers under isolated medical supervision in the original Wuhan strain that circulated widely in 2020.
Since then, the highly transmissible variant of Delta has dominated infections globally, making vaccines less effective and increasing the number of cases across the UK, US and elsewhere. Delta’s rapid rise led researchers and challenging UK testing partner hVivo Services Ltd. to focus on trying to grow the variant in the lab.
With colleagues in the Netherlands, hVivo has managed to get the Delta strain to mature during the seed phase, said Andrew Catchpole, chief HVivo scientist and virologist, who oversees the manufacture of the virus. The London Clinical Research Company continues to grow the batch milliliter to milliliter of a specimen taken from an infected human.