To determine whether a difference in antibody to hepatitis B surface antigen (anti-HBs) response to a hepatitis B vaccine challenge dose existed among persons with a baseline anti-HBs level of 0 mIU/mL (group 1) and those with “non-zero” levels of 0.1–4.9 (group 2) and 5.0–9.9 (group 3) mIU/mL, according to the VITROS ECi anti-HBs assay.

Subanalysis of randomized clinical trial. Response was defined as a postchallenge anti-HBs level of at least 10 mIU/mL and 4-fold rise in anti-HBs level 2 weeks after a single challenge dose of 10 vs 20 µg Engerix-B. Baseline was defined as the anti-HBs level immediately before administration of the challenge dose.

Pediatric integrated healthcare system near Houston, Texas.

Three hundred nineteen US-born 16–19-year-olds who completed the hepatitis B vaccine series during the first year of life.

One hundred seventy-eight persons had zero (group 1) and 141 (114 group 2 and 27 group 3) had non-zero anti-HBs levels at baseline. Response to the challenge dose was significantly higher among those with non-zero vs zero anti-HBs levels, irrespective of challenge dosage; only 1 person with a non-zero anti-HBs level failed to respond to the challenge dose (group 3, 27/27 [100%] vs group 2, 113/114 [99%] vs group 1, 145/178 [82%]; P<.0001).

Among participants with residual anti-HBs levels less than 10 mIU/mL 16–19 years after primary hepatitis B vaccination during infancy, non-zero anti-HBs levels, with rare exception, indicated persistence of immune memory to HBsAg.

ClinicalTrials.gov Identifier: NCT01341275

Infect Control Hosp Epidemiol 2015;00(0):1–5

To report the prevalence of anaemia by demographic characteristics and its secular trend over 13 years for south-east Chinese pregnant women, and to determine the focus of anaemia prevention in Chinese pregnant women.

Prospective study of the data on Hb concentration and other demographic information from a large-scale population-based perinatal health surveillance system in south-east China.

Fourteen cities or counties in Jiangsu and Zhejiang provinces.

A total of 467 057 prenatal women who had participated in the perinatal health-care surveillance system and delivered babies from 1 January 1993 to 31 December 2005 and had a record of Hb in all three pregnancy trimesters.

The overall prevalence of anaemia among pregnant women was 39·6 % from 1993 to 2005. Anaemia prevalence increased from the first (29·6 %) to the second (33·0 %) and third (56·2 %) trimesters. The prevalence of anaemia was higher in villagers, in women with less education and in women with higher gravidity or parity. The prevalence of anaemia in all of the trimesters was higher in the spring, summer and autumn and lower in the winter. The prevalence decreased from 1993 to 2005, from 53·3 % to 11·4 % for the first trimester, 45·6 % to 22·8 % for the second trimester and 64·6 % to 44·6 % for the third trimester.

The prevalence of anaemia among pregnant women in Jiangsu and Zhejiang provinces decreased substantially from 1993 to 2005. However, anaemia in the third trimester is still a severe public health problem among pregnant women in these areas.