Sweden’s public health agency recommended on Monday that people 80 and over receive a second booster dose of coronavirus vaccine, which would be a fourth overall shot. The agency also warned that as the country loosens its pandemic restrictions the virus is spreading more rapidly among those at high risk of serious illness.
The country is one of few countries that will recommend a fourth dose, which goes beyond the initial shots. Experts say this booster should be given to all adults.
According to data published last week by the U.S. Centers for Disease Control and Prevention, the protection provided by booster shots tends not to decrease significantly after approximately four months. This means that people at high risk for serious complications or death from Covid-19 could need another dose.
Scientists and officials debated whether boosters were needed or recommended for different ages, even though a large number of countries had approved them. Omicron, which has evaded immune defenses more effectively than any previous variants, brought about a shift in this thinking. There was also increased support for boosters.
“We believe that people who are 80 years and older will benefit” from a second booster dose, said Anders Tegnell, chief epidemiologist at Sweden’s public health agency.
Some scientists argue that trying to give everyone another shot every few months is unrealistic, and that booster efforts should be focused instead on older adults — who appear to get the most benefit from boosters, according to C.D.C. data — and on people who are especially vulnerable because they have weakened immune systems or live in long-term care facilities like nursing homes.
Both vaccines in use in Sweden — those developed by Moderna and by Pfizer and BioNTech — are usually administered in two initial doses a few weeks apart. According to the Our World in Data at the University of Oxford, seventy-three per cent of Swedish residents are considered fully immunized or have received the initial two doses.
Many countries recommend that individuals with compromised immune system receive three shots as an initial vaccine, rather than two. These people would be recommended booster shots on the same basis that those who have received the two-dose standard initial vaccination.
Recent research shows that even though it is less effective against Omicron over time, an initial vaccine, with no boosters, can still be very protective against severe illness or death.
Sweden has lifted or reduced most of its pandemic restrictions, including the work-from-home requirements as well as limits on gathering size. Sweden experienced a surge in new cases per day in January like many other countries. The Omicron variant was responsible for this increase. However, the number has been declining in recent years.
Along with all people 80 or older, Sweden is recommending that others who live in nursing homes or who receive assisted-living services at home should also receive a second booster dose, at least four months after their first one, the country’s health agency said.