Liability and maternal immunization: in utero injury claims in the VICP

Vaccines and pregnancy: past, present, and future

Vaccination during pregnancy with certain vaccines can prevent morbidity and mortality in pregnant women and their infants. However, previous recommendations often focused on the potential risks of vaccines to the fetus when used during pregnancy. In recent years, additional data have become available on the absence of increased risks for adverse events associated with vaccines when administered during pregnancy and on their benefits to mothers and infants. Currently two vaccines - (i) inactivated influenza, and (ii) tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) - are recommended for use by all pregnant women by the United States Advisory Committee on Immunization Practices. Here we review the history of vaccination during pregnancy, the current status of recommendations for vaccination during pregnancy in the USA, and the potential for future advances in this area, including key barriers that must be overcome to accommodate these advances.

Priorities for CMV vaccine development

A multidisciplinary meeting addressed priorities related to development of vaccines against cytomegalovirus (CMV), the cause of congenital CMV (cCMV) disease and of serious disease in the immunocompromised. Participants discussed optimal uses of a CMV vaccine, aspects of clinical study design, and the value of additional research. A universal childhood CMV vaccine could potentially rapidly reduce cCMV disease, as infected children are sources of viral transmission to seronegative and seropositive mothers. A vaccine administered to adolescents or adult women could also reduce cCMV disease by making them immune prior to pregnancy. Clinical trials of CMV vaccines in women should evaluate protection against cCMV infection, an essential precursor of cCMV disease, which is a more practical and acceptable endpoint for assessing vaccine effects on maternal-fetal transmission. Clinical trials of vaccines to evaluate prevention of CMV disease in stem cell transplant recipients could use CMV viremia at a level triggering pre-emptive antiviral therapy as an endpoint, because widespread use of pre-emptive and prophylactic antivirals has rendered CMV-induced disease too rare to be a practical endpoint for clinical trials. In solid organ transplant patients, CMV-associated disease is sufficiently common for use as a primary endpoint. Additional research to advance CMV vaccine development should include identifying factors that predict fetal loss due to CMV, determining age-specific incidence and transmission rates, defining the mechanism and relative contributions of maternal reactivation and re-infection to cCMV disease, developing assays that can distinguish between reactivation and re-infection in seropositive vaccinees, further defining predictors of sequelae from cCMV infection, and identifying clinically relevant immune response parameters to CMV (including developing validated assays that could assess CMV antibody avidity) that could lead to the establishment of immune correlates of protection.

Translating vaccine policy into action: a report from the Bill & Melinda Gates Foundation Consultation on the prevention of maternal and early infant influenza in resource-limited settings

Immunization of pregnant women against influenza is a promising strategy to protect the mother, fetus, and young infant from influenza-related diseases. The burden of influenza during pregnancy, the vaccine immunogenicity during this period, and the robust influenza vaccine safety database underpin recommendations that all pregnant women receive the vaccine to decrease complications of influenza disease during their pregnancies. Recent data also support maternal immunization for the additional purpose of preventing disease in the infant during the first six months of life. In April 2012, the WHO Strategic Advisory Group of Experts (SAGE) on Immunization recommended revisions to the WHO position paper on influenza vaccines. For the first time, SAGE recommended pregnant women should be made the highest priority for inactivated seasonal influenza vaccination. However, the variable maternal influenza vaccination coverage in countries with pre-existing maternal influenza vaccine recommendations underscores the need to understand and to address the discrepancy between recommendations and implementation success. We present the outcome of a multi-stakeholder expert consultation on inactivated influenza vaccination in pregnancy. The creation and implementation of vaccine policies and regulations require substantial resources and capacity. As with all public health interventions, the existence of perceived and real risks of vaccination will necessitate effective and transparent risk communication. Potential risk allocation and sharing mechanisms should be addressed by governments, vaccine manufacturers, and other stakeholders. In resource-limited settings, vaccine-related issues concerning supply, formulation, regulation, evidence evaluation, distribution, cost-utility, and post-marketing safety surveillance need to be addressed. Lessons can be learned from the Maternal and Neonatal Tetanus Elimination Initiative as well as efforts to increase vaccine coverage among pregnant women during the 2009 influenza pandemic. We conclude with an analysis of data gaps and necessary activities to facilitate implementation of maternal influenza immunization programs in resource-limited settings.