Mona Marin

Mumps vaccination coverage and vaccine effectiveness in a large outbreak among college students--Iowa, 2006.

Following implementation of a routine childhood two-dose measles-mumps-rubella vaccination strategy, mumps disease levels dropped dramatically in the US and an elimination goal was set for 2010. However, a 2006 epidemic involved >5700 cases nationwide, with many reported among fully vaccinated college students. In an outbreak in two Iowa colleges, we investigated: (1) vaccination coverage using electronic records verified by provider records and (2) vaccine effectiveness assessed by comparison of dose-specific attack rates. Mumps was classified as typical (parotitis/orchitis) or atypical (parotid tenderness or submandibular/sublingual adenitis). Two-dose mumps vaccination coverage was 90% both for the student population (2128/2363) and case-students (97/108). Two-dose vaccine effectiveness was 76-88% with no significant difference for attack rates between one and two doses. Among two-dose vaccine recipients, 74% of the population (1482/2009) and 79% of the case-students (75/95) had received the second dose >10 years before. A large mumps outbreak occurred despite high two-dose vaccination coverage in a population most of whom had received the second dose >10 years before. Two-dose vaccine effectiveness was similar to previous one-dose estimates. Further studies are needed to examine the persistence of two-dose mumps vaccine-induced immunity and to determine whether US mumps elimination can be achieved with the current vaccination strategy.

Incidence and Clinical Characteristics of Herpes Zoster Among Children in the Varicella Vaccine Era, 2005–2009

BACKGROUNDnVaccine-strain herpes zoster (HZ) can occur after varicella vaccination. This study determined the number and proportion of HZ cases caused by vaccine-strain varicella zoster virus (VZV), assessed the positive predictive value of provider diagnosis of HZ, and computed HZ incidence rates in vaccinated and unvaccinated children.nnnMETHODSnWe used electronic medical records to identify all office visits with an HZ diagnosis for children aged <18 years in a managed care plan. Providers collected skin specimens and completed a questionnaire. Specimens were tested by polymerase chain reaction to identify wild-type or vaccine-strain VZV.nnnRESULTSnFrom May 2005 to September 2009, we enrolled 322 subjects. VZV was detected in 82% of specimens (84% wild-type, 15% vaccine-strain, 1% possible vaccine-wild-type recombinant). Among the 118 vaccinated subjects, VZV was detected in 70% (52% wild-type). The positive predictive value for provider diagnosis of definite HZ was 93% for unvaccinated and 79% for vaccinated children. The incidence of laboratory-confirmed HZ was 48 per 100,000 person-years in vaccinated children (both wild-type and vaccine-strain) and 230 per 100,000 person-years in unvaccinated children (wild-type only).nnnCONCLUSIONSnHZ incidence in vaccinated children was 79% lower than in unvaccinated children. Among vaccinated children, half of HZ cases were due to wild-type VZV.

Global Varicella Vaccine Effectiveness: A Meta-analysis

CONTEXT: Several varicella vaccines are available worldwide. Countries with a varicella vaccination program use 1- or 2-dose schedules. OBJECTIVE: We examined postlicensure estimates of varicella vaccine effectiveness (VE) among healthy children. DATA SOURCES: Systematic review and descriptive and meta-analysis of Medline, Embase, Cochrane libraries, and CINAHL databases for reports published during 1995–2014. STUDY SELECTION: Publications that reported original data on dose-specific varicella VE among immunocompetent children. DATA EXTRACTION: We used random effects meta-analysis models to obtain pooled one dose VE estimates by disease severity (all varicella and moderate/severe varicella). Within each severity category, we assessed pooled VE by vaccine and by study design. We used descriptive statistics to summarize 1-dose VE against severe disease. For 2-dose VE, we calculated pooled estimates against all varicella and by study design. RESULTS: The pooled 1-dose VE was 81% (95% confidence interval [CI]: 78%–84%) against all varicella and 98% (95% CI: 97%–99%) against moderate/severe varicella with no significant association between VE and vaccine type or study design (P > .1). For 1 dose, median VE for prevention of severe disease was 100% (mean = 99.4%). The pooled 2-dose VE against all varicella was 92% (95% CI: 88%–95%), with similar estimates by study design. LIMITATIONS: VE was assessed primarily during outbreak investigations and using clinically diagnosed varicella. CONCLUSIONS: One dose of varicella vaccine was moderately effective in preventing all varicella and highly effective in preventing moderate/severe varicella, with no differences by vaccine. The second dose adds improved protection against all varicella.

National Survey of Primary Care Physicians Regarding Herpes Zoster and the Herpes Zoster Vaccine

BACKGROUNDnThis study describes physicians perception of burden associated with herpes zoster (HZ) and postherpetic neuralgia (PHN), intentions for recommending the HZ vaccine, and perceived barriers to vaccination.nnnMETHODSnA national survey of 438 general internal medicine (GIM) and 433 family medicine (FM) physicians was conducted during November-December 2005.nnnRESULTSnThe survey response rate was 69%. Approximately 35% of GIM and FM physicians strongly agreed that HZ and PHN caused a significant burden of disease. For patients 60-79 years of age, > or =80% of GIM and FM physicians were somewhat or very likely to recommend HZ vaccine. In multivariate analyses, physicians who strongly agreed that HZ and PHN cause significant burden were more likely to recommend the vaccine to patients 60-79 years of age (odds ratio [OR], 2.75 [95% confidence interval [CI], 1.85-4.09]), whereas those who felt there was insufficient information about duration of protection (OR, 0.40 [CI, 0.24-0.67]), that the need to store HZ vaccine in a freezer was a definite barrier (OR, 0.31 [CI, 0.13-0.75]), or that their patients would not pay for the vaccine if it was not covered by insurance (OR, 0.57 [CI, 0.38-0.86]) were less likely to recommend it.nnnCONCLUSIONSnPrimary care physicians perceived a high level of burden from HZ and PHN and generally favored the HZ vaccine.

Fatal varicella due to the vaccine-strain varicella-zoster virus

We describe a death in a 15-mo-old girl who developed a varicella-like rash 20 d after varicella vaccination that lasted for 2 mo despite acyclovir treatment. The rash was confirmed to be due to vaccine-strain varicella-zoster virus (VZV). This is the first case of fatal varicella due to vaccine-strain VZV reported from the United States. The patient developed severe respiratory complications that worsened with each new crop of varicella lesions; vaccine-strain VZV was detected in the bronchial lavage specimen. Sepsis and multi-organ failure led to death. The patient did not have a previously diagnosed primary immune deficiency, but her failure to thrive and repeated hospitalizations early in life (starting at 5 mo) for presumed infections and respiratory compromise treated with corticosteroids were suggestive of a primary or acquired immune deficiency. Providers should monitor for adverse reactions after varicella vaccination. If severe adverse events develop, acyclovir should be administered as soon as possible. The possibility of acyclovir resistance and use of foscarnet should be considered if lesions do not improve after 10 d of treatment (or if they become atypical [e.g., verrucous]). Experience with use of varicella vaccine indicates that the vaccine has an excellent safety profile and that serious adverse events are very rare and mostly described in immunocompromised patients. The benefit of vaccination in preventing severe disease and mortality outweigh the low risk of severe events occurring after vaccination.

Herpes zoster vaccine effectiveness and manifestations of herpes zoster and associated pain by vaccination status

Options for managing herpes zoster (HZ)-related pain and complications have limited effectiveness, making HZ prevention through vaccination an important strategy. Limited data are available on HZ vaccine effectiveness against confirmed HZ and manifestations of HZ among vaccinated persons. We conducted a matched case-control study to assess HZ vaccine effectiveness for prevention of HZ and other HZ-related outcomes and a cohort study of persons with HZ to compare HZ-related outcomes by vaccination status. Cases were identified through active surveillance among persons age ≥60 years with HZ onset and health-care encounters during 2010-2011 in Southeastern Minnesota. Controls were age- and sex-matched to cases. Data were collected by medical record review and from participants via interviews and daily pain diaries. 266 HZ case-patients and 362 matched controls were enrolled in the vaccine effectiveness studies and 303 case-patients in the cohort study of HZ characteristics by vaccination status. Vaccination was associated with 54% (95% CI:32%-69%) reduction in HZ incidence, 58% (95% CI:31%-75%) reduction in HZ prodromal symptoms, and 70% (95% CI:33%-87%) reduction in medically-attended prodrome. HZ vaccine was statistically significant effective at preventing postherpetic neuralgia (PHN) measured at 30 d after rash onset, 61% (95% CI: 22%-80%). Among persons who developed HZ, no differences were found by vaccination status in severity or duration of HZ pain after rash onset. In this population-based study, HZ vaccination was associated with >50% reduction in HZ, HZ prodrome, and medically-attended prodrome.

Herpes Zoster-Related Deaths in the United States: Validity of Death Certificates and Mortality Rates 1979–2007

BACKGROUNDnHerpes zoster (HZ) vaccine was recommended in the United States to reduce HZ-associated morbidity. Vaccination may reduce HZ-associated mortality, but no strategy exists to monitor mortality trends.nnnMETHODSnWe validated HZ coding on death certificates from California, using hospital records as the gold standard, and applied the results to national-level data to estimate HZ mortality.nnnRESULTSnIn the validation phase of the study, among 40 available hospital records listing HZ as the underlying cause of death, HZ was the underlying cause for 21 (52.5%) and a contributing cause for 5 (12.5%). Among the 21 hospital records listing HZ as the underlying cause of death, the median age of decedents was 84 years (range, 50-99); 60% had no contraindications for HZ vaccination. Of the 37 available records listing HZ as a contributing cause of death, HZ was a contributing cause for 2 (5.4%) and the underlying cause for 6 (16.2%). Nationally, in the 7 years preceding the HZ vaccination program, the average annual number of deaths in which HZ was reported as the underlying cause of death was 149; however, based on our validation study, we estimate the true number was 78 (range, 31-118).nnnCONCLUSIONSnNational death certificate data greatly overestimate deaths in which HZ is the underlying or contributing cause of death. The HZ vaccination program could prevent some HZ-related deaths, but the impact will be difficult to assess using national mortality data.

Risk Factors for Herpes Zoster Among Adults.

Background.u2003The causes of varicella-zoster virus reactivation and herpes zoster (HZ) are largely unknown. We assessed potential risk factors for HZ, the data for which cannot be obtained from the medical sector. Methods.u2003We conducted a matched case-control study. We established active surveillance in Olmsted County, Minnesota to identify HZ occurring among persons age ≥50 years during 2010–2011. Cases were confirmed by medical record review. Herpes zoster-free controls were age- and sex-matched to cases. Risk factor data were obtained by telephone interview. Results.u2003We enrolled 389 HZ case patients and 511 matched controls; the median age was 65 and 66 years, respectively. Herpes zoster was associated with family history of HZ (adjusted odds ratio [aOR] = 1.65); association was highest with first-degree or multiple relatives (aOR = 1.87 and 3.08, respectively). Herpes zoster was also associated with prior HZ episodes (aOR = 1.82), sleep disturbance (aOR = 2.52), depression (aOR = 3.81), and recent weight loss (aOR = 1.95). Stress was a risk factor for HZ (aOR = 2.80), whereas a dose-response relationship was not noted. All associations indicated were statistically significant (P < .05). Herpes zoster was not associated with trauma, smoking, tonsillectomy, diet, or reported exposure to pesticides or herbicides (P > .1). Conclusions.u2003We identified several important risk factors for HZ; however, the key attributable causes of HZ remain unknown.

Measles Outbreak Associated With Low Vaccine Effectiveness Among Adults in Pohnpei State, Federated States of Micronesia, 2014

Background.u2003A measles outbreak in Pohnpei State, Federated States of Micronesia in 2014 affected many persons who had received ≥1 dose of measles-containing vaccine (MCV). A mass vaccination campaign targeted persons aged 6 months to 49 years, regardless of prior vaccination. Methods.u2003We evaluated vaccine effectiveness (VE) of MCV by comparing secondary attack rates among vaccinated and unvaccinated contacts after household exposure to measles. Results.u2003Among 318 contacts, VE for precampaign MCV was 23.1% (95% confidence interval [CI], −425 to 87.3) for 1 dose, 63.4% (95% CI, −103 to 90.6) for 2 doses, and 95.9% (95% CI, 45.0 to 100) for 3 doses. Vaccine effectiveness was 78.7% (95% CI, 10.1 to 97.7) for campaign doses received ≥5 days before rash onset in the primary case and 50.4% (95% CI, −52.1 to 87.9) for doses received 4 days before to 3 days after rash onset in the primary case. Vaccine effectiveness for most recent doses received before 2010 ranged from 51% to 57%, but it increased to 84% for second doses received in 2010 or later. Conclusions.u2003Low VE was a major source of measles susceptibility in this outbreak; potential reasons include historical cold chain inadequacies or waning of immunity. Vaccine effectiveness of campaign doses supports rapid implementation of vaccination campaigns in outbreak settings.

Challenges With Controlling Varicella in Prison Settings Experience of California, 2010 to 2011

This article describes the epidemiology of varicella in one state prison in California during 2010 and 2011, control measures implemented, and associated costs. Eleven varicella cases were reported, of which nine were associated with two outbreaks. One outbreak consisted of three cases and the second consisted of six cases with two generations of spread. Among exposed inmates serologically tested, 98% (643/656) were varicella-zoster virus seropositive. The outbreaks resulted in > 1,000 inmates exposed, 444 staff exposures, and >