Effectiveness of the live zoster vaccine during the 10 years following vaccination: real world cohort study using electronic health records.

OBJECTIVES: To assess the effectiveness of live zoster vaccine during more than 10 years after vaccination; and to describe methods for ascertaining vaccine effectiveness in the context of waning. DESIGN: Real world cohort study using electronic health records. SETTING: Kaiser Permanente Northern California, an integrated healthcare delivery system in the US, 1 January 2007 to 31 December 2018. POPULATION: More than 1.5 million people aged 50 years and older followed for almost 9.4 million person years. MAIN OUTCOME MEASURE: Vaccine effectiveness in preventing herpes zoster, postherpetic neuralgia, herpes zoster ophthalmicus, and admission to hospital for herpes zoster was assessed. Change in vaccine effectiveness by time since vaccination was examined using Cox regression with a calendar timeline. Time varying indicators were specified for each interval of time since vaccination (30 days to less than one year, one to less than two years, etc) and adjusted for covariates. RESULTS: Of 1 505 647 people, 507 444 (34%) were vaccinated with live zoster vaccine. Among 75 135 incident herpes zoster cases, 4982 (7%) developed postherpetic neuralgia, 4439 (6%) had herpes zoster ophthalmicus, and 556 (0.7%) were admitted to hospital for herpes zoster. For each outcome, vaccine effectiveness was highest in the first year after vaccination and decreased substantially over time. Against herpes zoster, vaccine effectiveness waned from 67% (95% confidence interval 65% to 69%) in the first year to 15% (5% to 24%) after 10 years. Against postherpetic neuralgia, vaccine effectiveness waned from 83% (78% to 87%) to 41% (17% to 59%) after 10 years. Against herpes zoster ophthalmicus, vaccine effectiveness waned from 71% (63% to 76%) to 29% (18% to 39%) during five to less than eight years. Against admission to hospital for herpes zoster, vaccine effectiveness waned from 90% (67% to 97%) to 53% (25% to 70%) during five to less than eight years. Across all follow-up time, overall vaccine effectiveness was 46% (45% to 47%) against herpes zoster, 62% (59% to 65%) against postherpetic neuralgia, 45% (40% to 49%) against herpes zoster ophthalmicus, and 66% (55% to 74%) against admission to hospital for herpes zoster. CONCLUSIONS: Live zoster vaccine was effective initially. Vaccine effectiveness waned substantially yet some protection remained 10 years after vaccination. After 10 years, protection was low against herpes zoster but higher against postherpetic neuralgia. TRIAL REGISTRATION: ClinicalTrials.gov number NCT01600079; EU PAS register number EUPAS17502.

Changes in Cervical Cytology Results and Human Papillomavirus Types Among Persons Screened for Cervical Cancer, 2007 and 2015-2017.

OBJECTIVES: Since 2006, the US human papillomavirus (HPV) vaccination program has led to decreases in HPV infections caused by high-risk vaccine-targeted HPV types (HPV 16/18). We assessed differences in high-risk HPV prevalence by cervical cytology result among 20- to 24-year-old persons participating in routine cervical cancer screening in 2015-2017 compared with 2007. MATERIALS AND METHODS: Residual routine cervical cancer screening specimens were collected from 20- to 24-year-old members of 2 integrated healthcare delivery systems as part of a cross-sectional study and were tested for 37 HPV types. Cytology results and vaccination status (≥1 dose) were extracted from medical records. Cytology categories were normal, atypical squamous cells of undefined significance, low-grade squamous intraepithelial lesions (SIL), or high-grade SIL/atypical squamous cells cannot exclude high-grade SIL. Prevalences of HPV categories (HPV 16/18, HPV 31/33/45/52/58, HPV 35/39/51/56/59/66/68) were estimated by cytology result for 2007 and 2015-2017. RESULTS: Specimens from 2007 (n = 4046) were from unvaccinated participants; 4574 of 8442 specimens (54.2%) from 2015-2017 were from vaccinated participants. Overall, HPV 16/18 positivity was lower in 2015-2017 compared with 2007 in all groups: high-grade SIL/atypical squamous cells cannot exclude high-grade SIL, 16.0% vs 69.2%; low-grade SIL, 5.4% vs 40.1%; atypical squamous cells of undefined significance, 5.0% vs 25.6%; and normal, 1.3% vs 8.1%. Human papillomavirus 31/33/45/52/58 prevalence was stable for all cytology groups; HPV 35/39/51/56/59/66/68 prevalence increased among low-grade SIL specimens (53.9% to 65.2%) but remained stable in other groups. CONCLUSIONS: Prevalence of vaccine-targeted high-risk HPV types 16/18 was dramatically lower in 2015-2017 than 2007 across all cytology result groups while prevalence of other high-risk HPV types was mainly stable, supporting vaccine impact with no evidence of type replacement.