The cost-effectiveness of antenatal varicella screening with post-partum vaccination of susceptibles.

Varicella infection during pregnancy or around the time of birth can result in serious complications for the mother and/or her child. However, infection during pregnancy is relatively rare as most women are infected during childhood. Immigrant mothers from certain tropical countries are at increased risk of infection, as these countries appear to have lower rates of infection during childhood. We used a cohort model to assess the potential costs and benefits of screening first-time pregnant mothers and then vaccinating those who are susceptible. The model was stratified by age and country of birth (Bangladesh or UK). The strategies evaluated were: (a) an initial verbal screen followed by a serological screen for those with a negative or uncertain history; (b) universal serological screening; and (c) the current strategy which is to treat cases as they arise. Post-partum vaccination was given to those who screen negative for VZV antibodies. The model suggested that the screening and vaccination strategies prevent cases in women compared with the current strategy. Verbal followed by serological screening may be cost-saving to the NHS for both UK- and Bangladesh-born women. Universal screening is more costly but more effective than verbal screening, and it may be cost-effective to universally screen younger immigrant mothers.