RESUMEN
OBJECTIVE: To document the duration of protection afforded by Oka/Merck varicella vaccine over a 7-year period. STUDY DESIGN: The subjects were healthy children 1 to 12 years of age originally enrolled in clinical studies to evaluate the primary immune response to varicella vaccine 6 weeks after vaccination. Each was monitored for antibody persistence, breakthrough infection, and household exposure to varicella to produce estimates of vaccine efficacy. RESULTS: The 6-year cumulative varicella antibody persistence rate was 99.5% (95% CI: 98.9%, 100.0%). The annual breakthrough rate through 7 years ranged from 0.2% to 2.3% per year; the estimated cumulative event rate was 6.5%. Comparison of the observed average annual breakthrough rate with the age-adjusted expected annual incidence rate of varicella in unvaccinated children corresponded to an estimated vaccine efficacy of 93.8% to 94.6%. Eighty vaccinated children were exposed to varicella in the household, resulting in 8 (10%) cases of infection. When compared with the historical attack rate of 86.8% in unvaccinated susceptible persons exposed to varicella in the household, this yields an estimated vaccine efficacy of 88.5% (95% CI: 80.9%, 96.1%). Varicella cases in vaccinated children generally were mild. CONCLUSION: The live attenuated varicella vaccine is highly effective in inducing persistent immunity and long-term protection against breakthrough varicella infection.
Asunto(s)
Anticuerpos Antivirales/inmunología , Vacuna contra la Varicela/inmunología , Varicela/inmunología , Distribución por Edad , Varicela/epidemiología , Varicela/prevención & control , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Masculino , Factores de Riesgo , Factores de TiempoRESUMEN
The effect of sectoral, scatter laser photocoagulation on proliferative sickle retinopathy (PSR) was investigated by reviewing fluorescein angiograms of 88 sickle cell-haemoglobin C patients enrolled in a controlled, randomised trial. Follow-up was for a median period of 2.9 years. Complete infarction of all PSR in an eye occurred in 7 of 74 treated eyes and 2 of 60 control eyes. Treatment resulted in significantly greater regression (decrease in number or size of PSR lesions) in eyes of patients aged < 25 years at enrollment but not in eyes of patients > or = 25 years at enrollment. Infarction of individual PSR lesions was significantly more common in treated eyes. Treated PSR was significantly more likely to infarct if small (< 15 degrees circumferential involvement) and if flat rather than elevated. New PSR was significantly less likely to develop in treated eyes.
Asunto(s)
Enfermedad de la Hemoglobina C/complicaciones , Coagulación con Láser , Retina/cirugía , Enfermedades de la Retina/cirugía , Adulto , Angiografía con Fluoresceína , Humanos , Enfermedades de la Retina/etiologíaRESUMEN
The effect of sectoral, scatter laser photocoagulation on proliferative sickle retinopathy (PSR) was investigated by reviewing florescein angiograms of 88 sickle cell-haemoglobin C patients enrolled in a controlled, randomised trial. Follow-up was for a median period of 2.9 years. Complete infarction of all PSR in an eye occurred in 7 of 74 treated eyes and 2 0f 60 control eyes. Treatment resulted in significantly greater regression (decrease in number and size of PSR lesions) in eyes of patients aged <25 years at enrollment but not in eyes of patients> or = 25 years at enrollment. Infarction of the individual PSR lesions was significantly more common in treated eyes. Treated PSR was significantly more likely to infarct if small (< 15 degrees circumferential involvement) and if flat rather than elevated. New PSR was significantly less likely to develop in treated eyes.
Asunto(s)
Humanos , Adulto , Enfermedades de la Retina/cirugía , Enfermedad de la Hemoglobina C/complicaciones , Rayos Láser , Retina/cirugía , Angiografía con Fluoresceína , Enfermedades de la Retina/etiologíaRESUMEN
The natural history of untreated proliferative sickle retinopathy (PSR) has been observed in 35 patients (40 eyes) with homozygous sickle cell (SS) disease and in 112 patients (114 eyes) with sickle cell-haemoglobin C (SC) disease over a mean follow-up period of 4.5 years (range 0.5-14.0 years). In both genotypes progression of PSR was most frequent between ages 20 and 39 years. Spontaneous regression was more common in SS disease (p = 0.01), and more likely to proceed to complete non-perfusion. In SC disease PSR tended to be stable in patients aged 40 and over, and non-perfused PSR lesions were significantly more likely to reperfuse (p = 0.01) than in SS disease. In both genotypes regression was not influenced by size or elevation of the PSR lesion. The tendency for PSR to regress in SS disease suggests that treatment is unnecessary in SS patients aged 40 and over.