According to etymology, the word immune derives from the Latin immunis, which means exempt from public service, untaxed; unburdened. By extension, the term immunity means exempt from a particular infectious disease, but the term is now in danger of being equated with exemption from employment because of vaccine mandates that have been implemented or proposed in some countries. In the UK, unvaccinated health-care workers in England faced the prospect of imminent dismissal for representing a perceived danger to both themselves and to vulnerable patients, although the UK government is now consulting on whether the mandate should be scrapped. Many vaccine mandates include those who are naturally immune—which constitutes a large proportion of health-care workers in view of SARS-CoV-2 exposure in the workplace. However, there are compelling arguments against such unilateral mandates that bear repeating from the standpoint of accumulated knowledge around viral respiratory tract infections and immunity.
First, it is well established that for single stranded RNA viruses such as influenza, natural immunity after recovery from infection provides better protection than vaccination, which needs to be undertaken annually because of waning vaccine immunity.1
The same has been shown for SARS-CoV-2; in one study, individuals exposed to natural infection were ten-times less likely to be reinfected compared with vaccinated individuals without natural infection (adjusted hazard ratio 0·02, 95% CI 0·01–0·04 for previous infection vs 0·26, 0·24–0·28 for vaccination). Individuals exposed to natural infection were also less likely to be admitted to hospital with COVID-19.2