Relation between smallpox vaccination and outcome of pregnancy

Safety of Administering Live Vaccines During Pregnancy: A Systematic Review and Meta-Analysis of Pregnancy Outcomes

Live-attenuated vaccines (LAV) are currently contraindicated during pregnancy, given uncertain safety records for the mother-infant pair. LAV might, however, play an important role to protect them against serious emerging diseases, such as Ebola and Lassa fever. For this systematic review we searched relevant databases to identify studies published up to November 2019. Controlled observational studies reporting pregnancy outcomes after maternal immunization with LAV were included. The ROBINS-I tool was used to assess risk of bias. Pooled odds ratios (OR) were obtained under a random-effects model. Of 2831 studies identified, fifteen fulfilled inclusion criteria. Smallpox, rubella, poliovirus, yellow fever and dengue vaccines were assessed in these studies. No association was found between vaccination and miscarriage (OR 0.98, 95% CI 0.87-1.10), stillbirth (OR 1.04, 95% CI 0.74-1.48), malformations (OR 1.09, 95% CI 0.98-1.21), prematurity (OR 0.99, 95% CI 0.90-1.08) or neonatal death (OR 1.06, 95% CI 0.68-1.65) overall. However, increased odds of malformations (OR 1.24; 95% CI 1.03-1.49) and miscarriage after first trimester immunization (OR 4.82; 95% CI 2.38-9.77) was found for smallpox vaccine. Thus, we did not find evidence of harm related to LAV other than smallpox with regards to pregnancy outcomes, but quality of evidence was very low. Overall risks appear to be small and have to be balanced against potential benefits for the mother-infant pair.

Smallpox: a disease of the past? Consideration for midwives

Smallpox infection was often more severe in pregnant women than in non-pregnant women or in men, regardless of vaccination status. Women with smallpox infection during pregnancy have higher rates of abortions, stillbirths, and preterm deliveries than women without the disease. Pregnant women have high incidences of hemorrhagic-type and flat-type smallpox, which are associated with extremely high fatality rates. Although smallpox was eradicated in the late 1970s, current international concern exists regarding the potential use of smallpox virus as an agent for bioterrorism. This manuscript reviews clinical aspects of smallpox, smallpox immunization, and outcomes in pregnant women.

The new cell culture smallpox vaccine should be offered to the general population

A series of major factors must be weighed in deciding whether or not, and to what extent, a particular country should consider pre-exposure vaccination for smallpox. These include the risk of a bioterrorist attack using smallpox, the risk of secondary spread from another country, the risks and benefits of vaccination, the effectivenes s of vaccination pre- and post-exposure, the prevalence of immunocompromised persons, the capacity of the medical care delivery system and the wealth of a nation. We review here the issues and variables relevant for policy making, propose a framework for country-specific decision making and suggest the World Health Organization has a key role to play, particularly with regard to lower-income countries. In doing so, we support the proposition.