прививка от гепатита B не уменьшает кол-во хронических носителей

[eugenegp]

Исследование пяти тысяч детей в Индии, половина которых была привита от гепатита B, показало, что вакцинация не снизила количество хронических больных/носителей этого вирусного гепатита.
Пост-вакцинный иммунитет к вирусу найден у 35% привитых.

Снижение вирусоносителей является ключевой целью вакцинации от гепатита B, т.к. именно хронические носители имеют повышенный риск заболеваний печени в будущем + являются разносчиками вируса.

По мнению редакции, результаты исследования также поддерживают вывод, что в Индии гепатит B является широко распространенным, но неопасным заболеванием.

http://timesofindia.indiatimes.com/home/science/Hepatitis-B-vaccines-efficacy-in-doubt/articleshow/45064258.cms

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[eugenegp.livejournal.com]

Hepatitis B vaccine’s efficacy in doubt
Rema Nagarajan, TNN | Nov 7, 2014, 04.46AM IST

A study of 5,000 children in rural areas of Andhra Pradesh, about half of whom had received the Hepatitis B vaccine (HBV), found that the vaccine provided protection to only about a third of those vaccinated and did not reduce the carrier rate for the disease.

The vaccination aims to reduce the number of chronic carriers who could infect others and themselves develop liver cancers or cirrhosis of the liver much later in life. If the study's finding - that the vaccine does not bring down the carrier rate - is right, it raises questions about the value of the vaccination and whether pouring public money into giving HBV makes sense.

The study conducted by the Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow and the National Institute of Nutrition, Hyderabad has been published in the latest issue of the journal Indian Pediatrics. Two editorials in the journal raised several questions regarding the universal immunization programme (UIP) itself. The study conducted among 5-11 year-olds in the rural areas of five districts in Andhra Pradesh found that only 35% of the children vaccinated with HBV had vaccine-induced immunity.


Dr T Jacob John, former head of the departments of Clinical Microbiology and Clinical Virology in Christian Medical College, Vellore in his editorial noted that "the frequency of chronic infection (carrier state with HSBAg) was equal in both the unvaccinated (0.17%) and the vaccinated (0.15%)". He further observed that "the immunological and epidemiological outcomes of rolling out JE (Japanese encephalitis), Hib (Haemophelia influenza B and HBV vaccines are not being monitored as UIP has no capacity for that function".

According to Dr John, HBV immunization ought to significantly lower breakthrough infection frequency in the immunized, and ensure zero incidence of chronic infection. He said the results of the study called for immediate further investigations on a much larger scale, adding that there might be a need to design a more efficient schedule for vaccine delivery.

"Getting less than optimum benefit for the investment is unfair to the people. UIP is in urgent need of re-engineering, with in-built capacity to fulfill management principles : to measure and document optimum outcomes - immunological and epidemiological - commensurate with the massive investment," wrote Dr John. He criticized the single-minded focus on assessing success in delivering vaccines or improving coverage of a vaccine without studying outcomes.

Another editorial by Dr Rajeev Kumar and Dr Jacob Puliyel of the paediatrics department in St Stephens Hospital, Delhi, said that if the findings of this study were replicated in other areas, it ought to prompt a re-evaluation of the need for this vaccine in the country's immunization programme.

Dr Puliyel and Dr Kumar noted that the Hepatitis-B vaccine is now being given as pentavalent vaccine in combination with DPT and Hib (Haemophilus influenzae type B) vaccines. They say that the efficacy of Hepatitis-B vaccine when given mixed with other vaccines "is likely to be even lower than what was reported in the study that was conducted with Hepatitis-B as a stand-alone vaccine."

Introduction of HBV vaccine was pilot-tested in 14 cities and 33 Districts in 2002-03 and extended to 10 States in 2007-08. In 2009, the WHO was requested to assess vaccine delivery success, not outcomes. GAVI (formerly the Global Alliance on Vaccines and Immunization) provided India with Rs 27.2 crore to study Hepatitis B vaccination in India but no efficacy study was undertaken and it was introduced into universal immunization in a phased manner.

According to the editorial, the findings of the pilot study support the contention that Hepatitis B is a widespread but benign disease in India possibly because of characteristics of the circulating virus strain and the genetic makeup of the population.