Israel and Iceland, two of the most vaccinated countries in the world, have recently seen major outbreaks of COVID-19. Both countries had fully vaccinated 60% of the population by July 1st. Yet by early August, Iceland had posted its largest daily total for the number of new infections since the pandemic began, and case numbers in Israel were soaring.
However, the question of whether vaccines are superior to natural immunity in terms of protection against infection has remained open. According to a Guardian article titled “Common myths about Covid – debunked”, which was written by a member of Independent SAGE, natural immunity is “not as good as the protection you get from being vaccinated”.
Yet a new paper suggests the reverse may be true: natural immunity is stronger and longer-lasting than vaccine-induced immunity.
Sivan Gazit and colleagues analysed a large sample of anonymised patient records from Israel. Their sample included two key groups: fully vaccinated people who’d never tested positive; and unvaccinated people who had tested positive.
In addition to matching these two groups for size, and average demographic characteristics, they controlled for ‘immune activation time’. This was done by limiting the sample to people who’d been vaccinated or infected between January 1st and February 28th, 2021.
Patients’ Covid outcomes (subsequent infection, hospitalisation or death) were measured during a follow-up period between June 1st and August 14th.
What did the researchers find? Of the 257 cases that were detected in the follow-up period, 93% occurred in the vaccinated group, and only 7% occurred in the previously infected group. And of nine hospitalisations, eight occurred in the vaccinated group, compared to just one in the previously infected group.
These results indicate that natural immunity confers substantially more protection against infection than vaccine-induced immunity. They also suggest that natural immunity confers more protection against hospitalisation, although one should be cautious here, as there were only nine hospitalisations in total.