"There is so little understanding of what's going on, and that's true even for scientists," says Senjuti Saha, a molecular microbiologist and director of the Child Health Research Foundation in Dhaka, Bangladesh. ...a team led by Penny Moore, a virologist at the NICD and the University of the Witwatersrand in Johannesburg, is measuring the ability of neutralizing, or virus-blocking, antibodies triggered by previous infection and vaccination to stop Omicron infecting cells. Ultimately, researchers will want to conduct case-controlled studies, in which two groups of participants are matched in terms of age, vaccination status and health conditions. Surveillance efforts in Brazil and some other countries are taking advantage of a distinctive result on a particular PCR test that could allow them to pinpoint potential Omicron cases for sequencing, says virologist Renato Santana at the Federal University of Minas Gerais in Brazil.