Västerbottens-Kuriren was the first to draw attention to the study, which has not yet been published in a scientific journal.
The study has been sent to the prestigious journal The Lancet, where it is currently under scrutiny by other researchers before it could be published.
The researchers from Umeå University who are behind the observational study are Peter Nordström, Marcel Ballin and Anna Nordström.
They have based the study on all people who have been vaccinated against covid-19 in Sweden and then also all people who have a registered infection with covid-19.
- The main result is that the vaccine effects disappear and they disappear quite dramatically after the effect you have after one month to the effect you have after six months, says Peter Nordström, who is a professor of geriatrics.
"Protection disappears over time"
Since the majority of the Swedish population is vaccinated with Pfizer's vaccine, these are above all the figures the researchers have been able to calculate.
- As it looks like the protection disappears over time and when it has been over six months, we do not have much protection left.
You have somewhere around 25 percent protection left if you had over 90 from the beginning, says Peter Nordström.
Third dose reduces infection rate
According to Peter Nordström, the results from the study have provided support for what happens when you now give a third dose, when the infection rates fall.
- The clearest example that this could be true is from Israel, where they were absolutely the first to vaccinate the entire population and then managed to put down the infection in principle completely.
But then when six months had passed, they got a new wave that was higher than the previous waves of covid infection they had seen.
Then they quickly gave large parts of the population a third dose and then they managed to beat that wave as well.