LONDON (Reuters) – British Prime Minister said on Wednesday it would be some months before all the most vulnerable people received COVID-19 vaccines with England’s health service boss saying the bulk of the jabs would be given between January and April.

“It will inevitably take some months before all the most vulnerable are protected,” Johnson told a media conference after Britain approved the first COVID vaccine tested in wide-scale clinical trials.

Simon Stevens, the chief executive of England’s health service, said the first vaccinations would begin this month.

“The bulk of this vaccination programme, either through this vaccine, or hopefully others as well that will join it will take place in the period January through to March or April for the at-risk population,” he said.