v-safe pregnancy registry protocol: March 18, 2021, version 2
Duration
The anticipated duration of an individual’s and infant’s inclusion of the v-safe pregnancy call center registry will be up to one year after vaccination, depending on the time point in pregnancy that a person is exposed to vaccine. The decision to discontinue the v-safe program or to modify v-safe procedures to scale back active telephone follow-up will be made in consultation with key stakeholders including the CDC COVID-19 Vaccine Task Force leadership and FDA.
Limitations and challenges
Limitations and challenges for v-safe pregnancy surveillance include the potential for limited enrollment and retention in the program given its voluntary nature. It might be difficult to contact pregnant and postpartum persons by phone, and to obtain medical records on all pregnant persons and infants. Furthermore, vaccinated pregnant persons who choose to participate in v-safe might be different from those who decline; therefore, rates of side effects and adverse events generated from v-safe might not be generalizable to the full population of pregnant vaccine recipients. Similarly, pregnant persons who choose to participate in the pregnancy registry might be those who are more likely to have concerns or have experienced adverse events. This potential bias will be minimized by the prospective nature of this surveillance system and by review of medical records and accurate characterization of events. Additionally, a sensitivity analysis examining only outcomes among those who were enrolled and monitored before an adverse pregnancy or birth outcome occurred will be performed. Finally, the information provided by v-safe pregnant participants for up to one year after vaccination might be impacted by recall bias, specifically among those on whom we are unable to obtain medical records.
Dissemination of information
Safety profile information from the registry may be presented to Advisory Committee on Immunization Practices (ACIP) subgroups (such as the Vaccine Safety Technical Subgroup [VaST]), ACIP meetings and other meetings that are requested. Further, at the conclusion of the registry, a final report will be written detailing the findings of this surveillance activity.
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