According to a study by the National Institute for Health and Welfare (THL), the majority of those infected with coronavirus in the spring still had large amounts of antibodies six months following the infection.
The Finnish health authority is carrying out an antibody study on over 1,000 adults who have received a confirmed positive coronavirus test within the last six months. The aim of the study is to determine how long antibodies can be detected in infected people, which should also give an indication of the long-term immunity against a reinfection.
To date, antibodies have been found in approximately 90 percent of the roughly 900 samples examined. The finding adds optimism to the long-term protection provided by the coronavirus vaccines, according to a THL press release.
It is not yet known what amount of antibodies is sufficient to protect against a new infection, or how long the protection lasts. Animal experiments have shown neutralising antibodies are likely to offer protection against a new symptomatic infection, though.
According to the THL, international research has shown that the neutralising antibodies produced by the new mRNA-vaccines were high in both young adults and the elderly. In clinical trials, the coronavirus vaccines have produced an equivalent or stronger antibody response than in a natural infection.
“The fact that antibodies last for this long on such a large proportion of those infected is an encouraging finding. In particular, the discovery of neutralising antibodies suggests long-term protection against reinfections,” said THL research manager Merit Melin in a press release.