The study was published in the journal Biomarkers.
They found that in general, higher antibody concentrations in serum were associated with higher concentrations in saliva, with the strongest relationships observed for IgA antibodies.
“Protection against bacterial infection is usually inferred by measuring antibody levels in blood serum,” said lead study author Dr Jennifer Heaney.
“But taking blood samples involves a number of logistical considerations and may not always be feasible, especially in developing countries or where children are involved. Saliva sampling is non-invasive, requires no specialist training or equipment, and may be more cost-effective,” Heaney added
For the study, samples of both blood and saliva were taken from 72 healthy adults.
There samples were then analysed to test for concentrations of IgG, IgM and IgA antibodies against 12 pneumococcal (Pn) antigens.
“The suggestion that antibody levels in saliva may be indicative of those in serum therefore has important implications for markers of immunity and vaccination in many parts of the world,” Heaney stated.
While these preliminary results cannot yet be used to inform clinical decisions at an individual level, they further suggested that measuring antibodies in saliva may have promise in future epidemiological studies relating to vaccination against bacterial infections, particularly in developing countries.
“This research highlights the need for larger studies further to investigate the potential of saliva testing as a tool to assess immunity,” Heaney noted.