Low risk of reinfection confirms strong partial immunity and provides a rationale for saving millions of doses of vaccine for those with no immunity
Our primary weapon against Covid-19, vaccine, is in short supply and trial evidence is being overlooked to deliver one dose instead of the recommended two. Why not save millions of doses by deferring vaccinating people who already have defence mechanisms through natural infection  and already have greater immunity than delivered by a single dose?
About 3.7 million people in the UK have had confirmed infection. They are unlikely to get it again in this season. Of the 80 million plus people who have had confirmed infection globally, 31 have been confirmed as re-infected, showing immunity is remarkably strong, for at least six months but probably longer.  Since April 2020 I have been advocating for people who have recovered from proven COVID-19 to be at the vanguard for delivering essential services given their reduced risk. 
Is vaccinating people who already have partial immunity a priority in this critical period? If not, we can save vaccine, money and person-power, and focus on those who have no immunity from either prior infection or vaccination.
Emeritus Professor of Public Health
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Competing interests: No competing interests