Positive rates for rubella antibody in pregnant women and benefit of post-partum vaccination in a Japanese perinatal center.
OBJECTIVE
This study of pregnant women was undertaken to clarify their immune status for rubella and to evaluate the efficacy of, and adverse reaction to, post-partum rubella vaccination.


METHODS
We determined the levels of both rubella antibody by hemagglutination inhibition test and IgM antibody by enzyme-linked immunosorbent assay in the first gestational trimester and surveyed the positive rates for rubella antibody in pregnant women at our perinatal center; we recommended post-partum vaccination for women with poor immune status. We also evaluated the effectiveness of the vaccine and any adverse reaction.


RESULTS
Among 2741 pregnant women, 185 cases (6.7%) were seronegative for rubella virus. This rate was especially high (12.4%) in the population who had opted out of the vaccination because of a change in Japanese government policy. A total of 30 cases (1.1%) were positive or false-positive for IgM antibody, but no congenital rubella syndrome (CRS) developed. The seropositive rate was 93.3% in total, but this figure includes those who required post-partum vaccination (558 cases or 20.3%) because their titers were 16x or lower. Among 145 cases who received post-partum rubella vaccine, no severe adverse reaction was detected, and in all 37 cases with hemagglutination inhibition antibody titers of 8x or lower, the efficacy rate was 100%.


CONCLUSIONS
It is necessary to appropriately evaluate the CRS risk. Also, we need to emphasize the importance and safety of post-partum rubella vaccination in Japan.
Okuda
Mika
M
Department of Obstetrics, Gynecology and Molecular Reproductive Science, Yokohama City University Graduate School of Medicine, Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan. m-okuda@zap.att.ne.jp
Yamanaka
Michiko
M
Takahashi
Tsuneo
T
Ishikawa
Hiroshi
H
Endoh
Masaya
M
Hirahara
Fumiki
F
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D007564:Japan; D008875:Middle Aged; D049590:Postpartum Period / Q000276:immunology*; D011247:Pregnancy / Q000276:immunology*; D012411:Rubella Vaccine / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D012412:Rubella virus / Q000276:immunology*
D000914:Antibodies, Viral; D007075:Immunoglobulin M; D012411:Rubella Vaccine; C040901:rubella antibodies