The roll-out of the new Covid-19 vaccines is welcomed. But it is not a ‘silver bullet’. There are two main reasons why adherence to protective behaviours is still required.
First, the vaccines will increase the likelihood of preventing illness from developing in individuals, but the extent to which they prevent transmission of the virus from asymptomatic carriers is not yet known and is unlikely to be known for several months.
Second, even if the vaccines do prevent transmission, we are unlikely to achieve population immunity. Even with 90% real-world efficacy for the vaccine, the new variants of the virus would require about 90% of the population to be vaccinated, and the Department for Health and Social Care estimate that take-up will not be higher than 75%.1
Therefore, public adherence to protective behaviours – hand-cleansing, physical distancing, wearing face-coverings, use of ventilation, self-isolation – is likely to remain crucial for the foreseeable future. Research evidence suggests that some people who have been vaccinated might reduce their adherence to protective behaviours. In the context of the more transmissible B1117 variant of the SARS- CoV-2 virus, such a reduction in adherence is likely to lead to greater spread, further harmful variants, and many more people ill, hospitalised, suffering from long-COVID, and dead.