The Joint Committee on Vaccination and Immunisation (JCVI) makes recommendations about priorities for vaccination rollout and its primary aim in the first phase has been to minimise death and severe illness from Covid-19. Its analysis found that this was best achieved by protecting the vulnerable rather than reducing the spread of the virus, particularly as it remains uncertain how much current vaccines prevent transmission.
The question then becomes statistical: who is most at risk of catching and then dying from Covid? Two major independent studies, QCovid and OpenSafely, have analysed millions of general practice records and concluded that someone’s age is the key risk factor, with the risk of death from Covid roughly doubling for each six-seven years of additional age. For registrations in England and Wales to 15 January, 74% of Covid deaths were in people aged 75 and over. Even if the aim were to save the most years of life, JCVI found that it would be best to focus on the elderly first: older people’s increased risk is sufficient to dominate their shorter life expectancy.
The JCVI has defined nine priority groups down to people aged 50, which together comprise 99% of Covid deaths. These start with vaccinating older ages and those with serious health conditions, such as kidney disease, who had been advised to shield. People who provide health and social care are both at extra risk themselves and key in transmission and have been put among urgent groups. Although male sex, ethnicity and deprivation are independent risk factors even after allowing for age and medical conditions, OpenSafely found that each at most doubles the risk, so age is still the dominant factor in the prioritisation.
The UK’s vaccine development, procurement and rollout have been extremely effective. YouGov surveys estimate about 80% of UK adults are willing to get a Covid-19 vaccine, but early data shows some groups are more reluctant: take-up in black people over 80 may be around half that of white people over 80. It is unknown whether targeted campaigns can counter such hesitancy.
• David Spiegelhalter is chair of the Winton Centre for Risk and Evidence Communication at Cambridge. Anthony Masters is statistical ambassador for the Royal Statistical Society
