This illustration, created at the Centers for Disease Control and Prevention (CDC), reveals ultrastructural morphology exhibited by coronaviruses. A novel coronavirus, named Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), was identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China in 2019. The illness caused by this virus has been named coronavirus disease 2019 (COVID-19). (CDC/Alissa Eckert, MS)

The phase I trial in healthy adult volunteers began in April. More than 1,000 immunisations have been completed and follow-up is currently ongoing.

The next study will enrol up to 10,260 adults and children and will involve a number of partner institutions across the country.

The phase II part of the study involves expanding the age range of people the vaccine is assessed in, to include a small number of older adults and children:

• Aged 56-69 • Aged over 70 • Aged between 5-12 years