Management of varicella contacts in pregnancy: VZIG or vaccination?

Background: Varicella infection during pregnancy poses a serious risk for both foetus and mother. It has been suggested that it would be more cost-effective to screen antenatally with post-partum vaccination, which occurs in the US, than the current policy of checking immune status post varicella exposure, with VZIG administration where necessary. Additionally, it is doubtful whether the current policy provides best patient care, when a vaccine is available.

Objectives: The study aims to retrospectively compare the cost of the current policy with a cost estimate for antenatal screening with post-partum vaccination in NI.

Study Design: A cost estimate of antenatal screening of primigravidas, with post-partum vaccination, was calculated for two models: (1) verbal screening, with serological testing of those with no history of varicella infection and (2) serological screening of all primigravidas.

Results: The cost of VZIG issued to pregnant women in 2006 was pound100,800; 43% of births were to primigravidas therefore the estimated cost of VZIG issued to multigravidas was pound58,100. The cost of verbal screening with post-partum vaccination is estimated at pound23,750 p.a., saving pound34,350 over current policy. The estimated cost of screening all primigravidas with post-partum vaccination is pound43,000, saving pound15,100.

Conclusions: This retrospective study suggests that in NI either of the proposed antenatal screening strategies would be less costly than current practice. This finding supports the suggestion that varicella immunity testing should be included in the Antenatal Infectious Diseases Screening Programme, either as part of the universal vaccination programme or solely as an antenatal programme.