With distinct uncertainty as to whether having been infected with covid-19 gives immunity relaxing lockdown will pruoduce a further wave of infection. Herd immunity would seem to be a myth. It raises questions as to the efficacy of lockdown and its relaxation. Those that are vulnerable will die if infected. This will remain true until such time as a cure is produced. The only function of lockdown would appear to be keeping infection tomanageable levels. But continued lockdown will destroy the economy and the food chain.