The researchers have analyzed data from all Swedes from the start of the pandemic until October last year, ie before the omikron variant came to Sweden.
The study shows that unvaccinated people who have had an infection had a significantly lower risk of falling ill a second time.
The risk of a new infection in these people was 95 percent lower for up to 20 months compared to people who were both unvaccinated and who had not undergone a previous infection.
Best protection after both vaccine and infection
Among those who both had an infection and received one or two vaccine doses, the risk of re-onset with the need for hospital care was a further 94 and 90 per cent lower, respectively, than for unvaccinated people who had only undergone infection.
Thus, those who had both been infected and vaccinated had the best protection, although relapse in both groups was rare.
- The infection itself is linked to a low risk of becoming ill a second time, but this of course does not mean that it is smart to expose yourself to infection, given the increased risk of complications and death that the infection entails.
Vaccination is therefore preferable.
Regardless of whether you have had covid-19 or not, it is wise to take the doses that are offered, says Marcel Ballin, doctoral student in geriatrics at Umeå University and co-author.