Immune status of health care workers to measles virus: evaluation of protective titers in four measles IgG EIAs

Immunity against vaccine-preventable diseases in Finnish pediatric healthcare workers in 2015

“…It has also been shown that commercial EIA-tests fail to detect up to 10% of vaccine-induced measles IgG antibodies [33]. This might be the case with our cohort as well, and thus, a larger percentage of the nurses may be clinically protected than were shown to be antibody positive.…”

Calibration and Evaluation of Quantitative Antibody Titers for Measles Virus by Using the BioPlex 2200

“…In this study, the correlation of the quantitative result of the BioPlex 2200 MMRV IgG assay and the reference method (PRNT) is higher for "nonequivocal" specimens (Ͼ192 mIU/ml) and specimens with low concentrations of neutralizing antibody do not correlate well. This observation has been previously reported for other EIA methods and is attributed to the fact that PRNT only measures neutralizing IgG, whereas EIA-based tests measure total anti-measles IgG (14,15,20,26,29). This lack of sensitivity may lead to an underestimation of the number of protected individuals in seroepidemiological studies.…”

“…A study examining sera from health care workers in the Netherlands found that the seropositivity rates of four different qualitative EIAs compared to PRNT ranged from 89 to 97%, with the greatest variation in the cohort born in from 1975 to 1985, suggesting waning immunity in individuals with antibodies generated from a single MMR vaccine rather than natural exposure. The EIA that performed best was an in-house Luminex beadbased multiplex assay that used purified whole virus that provided an efficient display of the measles glycoproteins (29). Dorigo-Zetsma et al found that equivocal results in the EIAs were positive by PRNT; however, in the present study, 26/74 equivocal BioPlex specimens were not immune by PRNT.…”

A review of testing used in seroprevalence studies on measles and rubella

“…Comparisons of sensitivity and specificity of MTP EIA, IA, HAI and PRNt assays for measles and rubella have been published and demonstrate large variation in assay performance. PRNt is considered to have superior analytical sensitivity [35,36] up to 10% of EIA results being falsely negative compared with PRNt [18,37]. Suggested reasons for the differing sensitivity of PRNt and MTP EIAs is the higher dilution of serum in the MTP EIA, longer incubation time in the PRNt and the decreased ability of MTP EIA to detect neutralising antibodies [17].…”