By Jennifer Rigby LONDON (Reuters) – Leading South African scientists are set to investigate COVID-19 and HIV in tandem, amid mounting evidence that the collision of the two pandemics could be generating new coronavirus variants. The team at the Network for Genomic Surveillance in South Africa (NGS-SA), which first alerted the world to the COVID variant Omicron, said it was time for a “systematic” investigation of what happens when patients with untreated HIV get COVID-19. A number of studies, including one published by the team last week, have found that people with weakened immune systems – …