As COVID-19 hit England last spring, the health service faced workforce shortages of over 100,000 staff. Around 40% of the staffing shortfall was in nursing. Capacity constraints of all kinds have been an important backdrop to the management of the pandemic. Equipment and buildings matter, but throughout COVID-19 the key risk was not having enough staff to safely treat all the patients needing care. Anita Charlesworth discusses what action is now required.