Susceptibility to cytomegalovirus, parvovirus B19 and age-dependent differences in levels of rubella antibodies among pregnant women.

Infections caused by cytomegalovirus (CMV), parvovirus B19 (B19), and rubella can lead to serious complications in pregnant women. The aim of this study was to determine the susceptibility to CMV, B19, and rubella antibodies in pregnant women in Norway. Consecutive sera samples were collected from pregnant women in two different regions in Norway. Sera were collected from age groups; ≤19, 20-24, 25-29, 30-34, 35-39, and ≥40 years old. Of the 2,000 pregnant women tested, anti-CMV IgG was positive in 62.8% anti-parvovirus B19 IgG in 59.7% and anti-rubella IgG in 94.4%. CMV IgG susceptibility has decreased in pregnant women less than 30 years of age, from 60% in a study conducted in 1973-1974 to 37.2% in present study. There was a significant difference in CMV IgG seropositivity rate between the two regions (58.6% and 67.1%). Serum levels of rubella IgG was lowest in age group 25-29 years with a positivity rate of 91.0%. Women born before vaccination with two doses of MMR started, had both a higher positivity rate and significantly higher levels of rubella antibody titre, 96.1% and 82.2 IU/ml compared to those born after 92.9% and 41.7 IU/ml. Significantly lower anti-rubella IgG titre found in the youngest age groups highlights the need for continued antenatal screening. A considerable increase in anti-CMV-IgG seropositivity rate was observed and might be associated with higher rate of breastfeeding and a higher percentage attending day-care centres.

A non-living nasal influenza vaccine can induce major humoral and cellular immune responses in humans without the need for adjuvants.

Twenty-eight healthy adult volunteers were immunized intranasally with an inactivated whole-virus influenza vaccine based on the strain A/New Caledonia/20/99 (H1N1), either in saline or mixed with formaldehyde-inactivated Bordetella pertussis as a mucosal adjuvant, or in a thixotropic vehicle with mucoadhesive properties. After four doses, all groups of vaccinees developed significant IgG- and IgA-antibody responses, measured by ELISA, in respectively serum and nasal secretions. None of the volunteers had demonstrable hemagglutination inhibition (HAI) antibodies in serum before being immunized, whereas more than 80% of them reached HAI titers>or=40, considered protective, after immunizations. In addition, cellular immune responses, measured as significant increases in CD4+ T-cell proliferation and granzyme B-producing cytotoxic T-cells, were detected against the vaccine strain as well as against heterologous virus strains (H3N2). However, no additive effect on these responses could be demonstrated with use of B. pertussis or the thixotropic substance in the present vaccines. It appeared, actually, that the mucoadhesive vehicle containing the thixotropic substance was less efficient than were the two other formulations. An influenza vaccine made as a simple particulate formulation of inactivated virus, and given repeatedly onto the nasal mucosa, may thus be an attractive alternative to currently available vaccines.