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Tuesday, 18th of November 2008 Print
Dear Colleagues,


This study by Bialek and colleagues indicates, like other studies of even longer follow-up duration, that vaccination with 3 doses of hepatitis B vaccine gives excellent long-term protection against chronic HBV infection (none of the study participants developed chronic HBV infection).  Readers should note that there are no reliable markers for cellular immunity that can be used to study the long-term protection of hepatitis B vaccine.  The use of measures of humoral immunity (e.g. anti-HBs) provide an incomplete view of the total protection given by hepatitis B vaccine.  This study, like others, indicates that humoral immunity may wane over time, however, this does not mean that protection has disappeared and is only one factor for consideration in the role of a booster dose.  The WHO SAGE has constituted a Hepatitis Working Group that is reviewing the scientific knowledge on long-term protection.  In the recently concluded November 2008 SAGE meeting, the Working Group stated that current evidence supports over 20 years of HBV infection protection following full immunization with plasma derived vaccines in a variety of schedules.  The Working Group also noted that it is aware of new data from long term cohort studies, to be published soon, which they will review prior to the April 2009 SAGE meeting.






Steven Wiersma, MD, MPH
Medical Officer, Hepatitis Prevention

Immunization, Vaccines & Biologicals, Expanded Programme on Immunization
World Health Organization
Geneva, Switzerland


tel. +41-22-791-1511

mobile: +41-79-500-6581

email: wiersmas@who.int


In the more prosperous parts of India, sex ratios are uneven among newborns, with boys always more numerous than girls.

In this discussion on "Worsening sex ratio in India - some evidence from Mumbai," from the Indian Journal of Medical Research, Subramoney and Gupta review the evidence from that city and find that the best predictor of skewed sex ratios is the timing of the first ultrasound. Among those having an ultrasound within 2 months of their first prenatal visit, the sex ratio was 686 girls per 1000 boys, compared to 903 girls  per 1000 boys for those doing ultrasound later.

They conclude "Although a large number of biological and other factors can be hypothesized for worsening sex ratio in India, the available data demonstrate ultrasound misuse as a major culprit." Full text is at

Am I correct in believing that the use of ultrasound for sex determination and subsequent abortion is illegal in India?

Bob Davis
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