Lessons from the calculated risk behind the deployment of the Covid-19 vaccine in the UK

LONDON – The UK’s bold call to delay the administration of a second dose of a Covid-19 vaccine has put it ahead in the race to immunize the world against the disease.

Behind the decision: a group of 16 scientists who advocated a controversial decision to override the guidelines of some vaccine manufacturers in order to deliver more first doses to more people.

The gamble appears to have paid off, with incoming data indicating lasting protection against the disease after a single dose of the vaccine. But while some countries, like Canada, have followed the UK’s lead, others including the US refuse, saying it could pose a risk to public health.

The UK authorities’ decision draws lessons for other countries struggling to contain the pandemic. Indeed, the dosage debate raises difficult questions about whether some governments and their scientific advisers – for example in the European Union, where vaccination campaigns are extremely slow – are too risk averse.

In December, as a highly infectious variant of Covid-19 tore the UK apart, the group of scientists on the UK Joint Committee on Vaccination and Immunization concluded that the postponement of a second dose of vaccine until at 12 weeks could save lives.