Vaccine specialists listed several reasons for the spike in breakthrough infections, including that it’s been a while since the earliest vaccinations were administered, the increased vaccine coverage, the removed restrictions, and the incidence of the more contagious Delta strain.
Given the high inoculation rate, the share of those vaccinated among confirmed COVID-19 cases has risen is Sweden, which according to researchers is seen as a signal of waning vaccine protection.
The Swedish Public Health Agency reported that between 1-24 September 7 out of 10 COVID-related deaths were fully vaccinated individuals.
According to Farshid Jalalvand, a researcher in clinical microbiology at Lund University, there are several reasons why the proportion of fully vaccinated among the deceased has increased.
“The main reasons are probably that it has now been quite a while since the oldest ones were vaccinated, that the vaccine coverage has increased, that the restrictions have been eased, and that the Delta strain has taken over”, Jalalavand told the newspaper Svenska Dagbladet.
The Delta strain is known to spread more easily among both vaccinated and unvaccinated than the Alpha strain. According to Jalalavand, though, fully vaccinated people “generally have good protection”.
Gunilla Karlsson Hedestam, professor of vaccine immunology at the Karolinska Institute, said it is not unexpected that vaccine protection decreases over time.
“The mRNA vaccines are fantastic in that they could be developed so quickly and they reduce the risk of serious illness significantly. However, they don’t produce as high antibody levels as protein-based vaccines. The higher the antibody concentration in the blood after vaccination, the more robust and lasting the protection will be”, Karlsson Hedestam said.
At present, there are currently no protein-based COVID-19 vaccines on the global market, but Novavax and Sanofi Pasteur have both filed for approval by the WHO and in Europe, respectively.
Nevertheless, Gunilla Karlsson Hedestam called the idea of completely vaccinating yourself free from SARS-CoV-2 “overly optimistic”.
“We know that the COVID-19 vaccine reduces the risk of illness and death, which is very important, but at the same time we must accept that the breakthrough infections will increase and that we must continue to live with this virus, at least until we have an even better vaccine”, she mused, calling on her compatriots to avoid “certain risk situations” to keep the spread of infection down.
State epidemiologist Anders Tegnell confirmed that no vaccine offers 100-percent protection.
“Therefore, there will be mild cases where one dies with COVID-19, but not because of the disease. That proportion will get bigger and bigger the more people who are vaccinated”, Tegnell said.
At the same time, age is also seen as a factor, as the median age of those fully vaccinated who have died since 1 July has been over 80 years old. Yet, cases of infection in elder care have recently increased to their highest levels since February, and the proportion of the elderly among those infected has risen to some of the highest levels since mass testing began.
Since the start of the pandemic, Sweden, a nation of over 10 million, has seen 1.16 million cases with nearly 15,000 fatalities. Nearly 65 percent of the Swedish population is fully vaccinated.