Merck/Centers for Disease Control and Prevention Varicella Vaccine Pregnancy Registry: 19-Year Summary of Data From Inception Through Closure, 1995-2013.

BACKGROUND: The VARIVAX® Pregnancy Registry was established in 1995 to monitor pregnancy outcomes of women who received varicella vaccine (ie, VARIVAX) inadvertently while pregnant. METHODS: Health care providers and consumers sent voluntary reports about women who received VARIVAX 3 months before or during pregnancy. Follow-up occurred to evaluate pregnancy outcomes for birth defects. Outcomes from prospectively reported pregnancy exposures (ie, reports received before the outcome of the pregnancy was known) among varicella-zoster virus (VZV)-seronegative women were used to calculate rates and 95% confidence intervals (CIs). RESULTS: From 17 March 1995 through 16 October 2013, 1601 women were enrolled-966 prospectively-among whom there were 819 live births. Among 164 infants born to women who were VZV seronegative at the time of vaccination, no cases of congenital varicella syndrome (CVS) were identified (rate, 0 per 100, 95% CI, 0.0-2.2) and the birth prevalence of major birth defects was 4.3 per 100 liveborn infants (95% CI 1.7-8.6) with no pattern suggestive of CVS. No defects consistent with CVS were identified in any registry reports. CONCLUSIONS: Data collected through the VARIVAX pregnancy registry do not support a relationship between the occurrence of CVS or major birth defects and varicella vaccine exposure during pregnancy, although the small numbers of exposures cannot rule out a low risk. VARIVAX remains contraindicated during pregnancy.

A post hoc analysis utilizing the FDA toxicity grading scale to assess injection site adverse events following immunization with the live attenuated Zoster Vaccine (ZVL).

BACKGROUND: ZOSTAVAX (ZVL; Zoster Virus Live), is a single dose, live, attenuated vaccine licensed for the prevention of herpes zoster (HZ) and post herpetic neuralgia (PHN) in adults ≥50 years of age. Injection site adverse events (AEs) of erythema, swelling and pain were solicited within 5 days post vaccination in the 2 pivotal studies of ZVL; ZEST (ZOSTAVAX Efficacy and Safety Trial) and SPS (Shingles Prevention Study). Protocol specified criteria were used to report the frequency and intensity of injection site AEs in ZEST and SPS studies. Subsequently, the FDA Toxicity Grading Scale provided guidance for uniform assessment of AEs across all adult vaccine clinical trials. The objective of this post-hoc analysis was to categorize the previously reported injection site AEs in two pivotal trials of ZVL according to the current FDA Toxicity Grading Scale. METHODS: The current FDA Toxicity Grading Scale provides a measure for classifying injection site AEs by four grades [Grade 1 (mild); Grade 2 (moderate); Grade 3 (severe) and Grade 4 (life threatening)]. Injection site erythema, swelling, and pain intensity gradings were assigned to the respective FDA Toxicity Grade based on this appropriation. A descriptive analysis of the proportion and risk difference (within 95% confidence intervals) of injection site AEs per the FDA Toxicity Grading Scale is provided. RESULTS: The frequency of injection site AEs (erythema, swelling, pain) after subcutaneous vaccination with ZVL were higher in recipients of ZVL compared with placebo. Majority of the injection site AEs observed were Grade 1 (mild) or Grade 2 (moderate) in intensity. Additionally, Grade 3 (severe) injection site AEs were observed infrequently. CONCLUSIONS: Application of the FDA Toxicity Grading Scale provides a uniform AE assessment tool across different adult vaccines. This post hoc summary of injection site AEs using FDA Toxicity Grading Scale provides further evidence of low frequency of severe injection site AEs post ZVL vaccination.

Herpes zoster vaccine live: A 10 year review of post-marketing safety experience.

BACKGROUND: Zoster vaccine is a single dose live, attenuated vaccine (ZVL) indicated for individuals ≥50 years-old for the prevention of herpes zoster (HZ). Safety data from clinical trials and post-licensure studies provided reassurance that ZVL is generally safe and well tolerated. The objective of this review was to provide worldwide post-marketing safety information following 10 years of use and >34 million doses distributed. METHODS: All post-marketing adverse experience (AE) reports received worldwide between 02-May-2006 and 01-May-2016 from healthcare professionals following vaccination with ZVL and submitted to the MSD AE global safety database, were analyzed. RESULTS: A total of 23,556 AE reports, 93% non-serious, were reported. Local injection site reactions (ISRs), with a median time-to-onset of 2 days, were the most frequently reported AEs followed by HZ. The majority of HZ reports were reported within 2 weeks of vaccination and considered, based on time-to-onset, pathogenesis of HZ, and data from clinical trials, to be caused by wild-type varicella-zoster virus (VZV). HZ confirmed by PCR analysis to be VZV Oka/Merck vaccine-strain was identified in an immunocompetent individual 8 months postvaccination and in 4 immunocompromised individuals. Disseminated HZ was reported very rarely (<1%) with 38% occurring in immunocompromised individuals. All reports of disseminated HZ confirmed by PCR as VZV Oka/Merck vaccine-strain were in individuals with immunosuppressive conditions and/or therapy at the time of vaccination. CONCLUSIONS: The safety profile of ZVL, following 10 years of post-marketing use, was favorable and consistent with that observed in clinical trials and post-licensure studies.

Closure of varicella-zoster virus-containing vaccines pregnancy registry - United States, 2013.

Vaccines that contain live attenuated varicella-zoster virus (VZV) (Varivax, ProQuad, and Zostavax [all products of Merck & Co., Inc.]) are contraindicated during pregnancy. To monitor the pregnancy outcomes of women inadvertently vaccinated with VZV-containing vaccines immediately before or during pregnancy, Merck and CDC established the Merck/CDC Pregnancy Registry for VZV-Containing Vaccines in 1995. This report updates previously published summaries of registry data, provides the rationale for the closure of the registry, and describes plans for continued monitoring of the safety of these vaccines when inadvertently administered to pregnant women or immediately before pregnancy. From inception of the registry in 1995 through March 2012, no cases of congenital varicella syndrome and no increased prevalence of other birth defects have been detected among women vaccinated within 3 months before or during pregnancy. Although a small risk for congenital varicella syndrome cannot be ruled out, the number of exposures being registered each year (approximately two varicella-susceptible women exposed during the high-risk period for congenital varicella syndrome) is now too low to improve on the current estimate of the risk.