Africa accounts for less than 3 percent of global coronavirus cases, but the continent is seeing an acceleration in confirmed numbers. Last week, the World Health Organization said confirmed cases on the continent had doubled to 200,000 over 18 days. Many African nations made a mammoth effort to quickly bring in lockdowns and sanitary measures to prevent the spread of Covid-19, but the economic cost of that has been enormous. We speak to Dr Mary Stephen from the WHO's regional office.