Early Career Research Award Update: Dr. Maria Talavera-Barber
Dr. Talavera-Barber, Assistant Professor of Pediatrics at the University of South Dakota Sanford School of Medicine, was a 2019 recipient of a National CMV Foundation Early Career Research Award. In this blog post, she discusses the impact of her research on CMV antibody levels in pregnant women and newborns.
Title: “Antibody Titers Against Human Cytomegalovirus gM/gN Among Pregnant Women and Their Infants”
Congenital infections pass from a mother to her baby through the placenta. Congenital cytomegalovirus (cCMV) infection can cause cerebral palsy, sensorineural hearing loss, and intellectual disabilities in children infected with CMV before they were born. For some congenital infections such as Rubella, natural immunity or vaccinations that produce antibodies in the mother can protect the baby. However, cCMV infection can occur among women who have been infected with CMV prior to pregnancy and have natural immunity. Thus, natural maternal immunity does not completely protect the unborn baby from congenital CMV infection. Therefore, preventing cCMV infection remains a major opportunity for improving children’s health and well-being worldwide
Several CMV virus components have been incorporated into vaccines with measurable antibody levels. These viral parts include outer layer glycoprotein B (gB) and partner glycoproteins gM/gN. A vaccine against CMV glycoprotein B (gB) has been tested in a clinical trial to prevent cCMV transmission. This vaccine was only effective in half the patients given the vaccine, likely because the antibodies that resulted from the vaccine were not highly functional. Therefore, an anti-gB vaccine alone may not be ideal for preventing congenital infection, and other anti-CMV antibodies may need to be generated by a vaccine. It has been shown that CMV-infected people can produce neutralizing antibodies against the CMV glycoprotein complex, gM/gN, but these antibodies have not been studied for their role in protection in pregnant women.
The objective of our study was to determine the levels of antibodies against gM/gN among pregnant women and their newborn infants, in comparison with anti-gB and total anti-CMV IgG antibodies. We studied paired blood samples from 92 mothers and their newborn babies to see if anti-gM/gN antibodies from mothers cross the placenta into their infants. We found that mothers with natural CMV immunity had significantly lower levels of anti-gM/gN antibodies compared to anti-gB antibodies, and the same was found for their infants, including those born prematurely. We also discovered that the levels of anti-gM/gN antibodies did not correlate with serum neutralizing activity, indicating that neutralizing anti-gM/gN antibodies could be boosted by a vaccine. In addition, we determined that nearly 10% of CMV antibody positive mothers had antibodies with low avidity and low neutralizing capacity, confirming that natural immunity may not provide strong protection against cCMV transmission among some women. Based on these findings, we conclude that including glycoprotein gM/gN components in a CMV vaccine may boost the anti-CMV antibody response in women with natural CMV immunity and may help provide extra protection during pregnancy to prevent congenital CMV transmission to their babies.
You can see the publication of this research by visiting here
Category: Clinical, "Fueling Our Mission"