1048Pregnancy Registry for Varicella-Zoster Virus-Containing Vaccines: 18-Year Summary of Pregnancy Outcomes
Bibliographic record
Abstract
Background. VARIVAX®, ProQuad® and ZOSTAVAX® contain live attenuated varicella zoster virus (VZV) and are contraindicated during pregnancy. Merck and Co., Inc. and the Centers for Disease Control and Prevention collaboratively established a pregnancy registry for VZV-containing vaccines to monitor congenital varicella syndrome (CVS) and other birth defects in offspring of women inadvertently exposed to these vaccines during pregnancy. A summary of 18 years of registry data is presented. Methods. Health-care providers from the United States, Puerto Rico, and Canada voluntarily report administration of VZV-containing vaccines to women within 3 months before or during pregnancy. Follow-up is conducted to obtain pregnancy outcomes. Reports are classified by timing of registry notification (before vs after pregnancy outcome is known), VZV serostatus at vaccination, and timing of exposure in relation to gestational age. The theoretical risk for CVS is defined as “high” if vaccination occurred during the 1st or 2nd trimester. Prospective reports (received before the outcome of pregnancy was known) are used for rate calculations. Metropolitan Atlanta Congenital Defects Program methodology is used to define birth defects and calculate rates. Results. From March 17, 1995 through March 16, 2013, 893 prospective reports with outcomes available for analysis were received. Most exposures (n = 886) were to VARIVAX. No features consistent with CVS were identified among all 810 live births in the registry or among those of varicella-susceptible women exposed during the high risk period (n= 95, rate = 0%, 95% confidence interval [CI] 0.0, 3.8). Major birth defects were reported in 18 offspring of women with pregnancy outcomes ≥20 weeks gestation resulting in a birth prevalence of 2.1 per 100 liveborn infants (95% CI 1.2, 3.4), similar to the prevalence in the general population. No specific pattern or clustering by type of defect was identified. Conclusion. We observed no cases of CVS and no increased prevalence for other birth defects after exposure to VZV-containing vaccines during pregnancy. However, the number of exposures is insufficient to exclude a very low risk of CVS in varicella-susceptible women exposed during the high risk period. VZV-containing vaccines remain contraindicated for pregnant women. Disclosures. All authors: No reported disclosures.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.004 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".