COVID-19: Reinfections amid ‘complex mix of immunity’
Omicron and its sub-variants have been dominating new surges of SARS-CoV-2 infections around the world and were behind South Africa’s fifth wave. The BA.4 and BA.5 sub-lineages unveiled yet more surprises about the evasive nature of these ever-emerging forms of SARS-CoV-2. They also hold clues for what to expect next and how to prepare. Aisha Abdool Karim reports.