The first potential benefit from vaccination mandates is reducing the transmission of COVID-19 in high-risk environments. This relies on the vaccinated being less likely to either carry or transmit the virus. With previous variants, there was strong evidence that vaccination significantly reduced the chance of catching and transmitting COVID-19. However, the difference between the vaccinated and unvaccinated has shrunk with Omicron. The UK data suggests that vaccination generally less than halves the risk of currently being infected with COVID-19. This protection wanes rapidly, making almost no difference more than three months after administration of the dose. By contrast, receiving a negative rapid antigen test in the very recent past is a much better indicator that one is not infected than one’s vaccination status.
The second potential benefit of vaccination mandates is that they reduce the pressure on the healthcare system. Unvaccinated people typically have much more severe symptoms than vaccinated people. For instance, figures from the UK Health Security Agency show that over-50s with a booster dose are 95 per cent less likely to die from Omicron than unvaccinated over-50s. Thus, every additional unvaccinated case creates a much larger load for the health system than an additional vaccinated case. Thus, by banning unvaccinated people from entering high-risk settings, the argument goes, we are protecting them and thus the health system.
As Omicron has taken off over the past few weeks, the rates of people testing positive for COVID-19 who are fully, partially, or unvaccinated have been very similar. Over the eight days from Saturday 12 February to Saturday 19 February, 267 out of every 100,000 unvaccinated persons tested positive for COVID-19. 220 out of every 100,000 partially vaccinated persons tested positive, and 224 out of every 100,000 fully vaccinated persons tested positive. In other words, if all you know about a person is their vaccination status, it is unlikely that will tell you much about their likelihood of testing positive for COVID-19.
Given a test-or-vaccine requirement is a workable alternative to reduce the risk of transmission in ultra-high risk settings, like healthcare, the only remaining ground for a vaccine-only mandate is this second benefit. However, with vaccination rates of 96 per cent and those remaining unvaccinated very unlikely to change their mind at this point, vaccine requirements are no longer serving the purpose of increasing uptake. Moreover, attempting to reduce hospitalisation by protecting unvaccinated people from infection only serves to spread out essentially inevitable infections over a longer time period. This may have marginal health system capacity benefits but it does not reduce the total numbers of cases which must be dealt with.
