Double-up measles vaccine for HIV kids, says study
[LUSAKA] Children infected with HIV may require repeated measles vaccination to gain adequate protection, according to new research.
The study in Zambia — published in the Journal of Infectious Diseases next week (1 August) — found that compared with healthy children, HIV-infected children were less able to maintain protective levels of antibodies against measles after an initial vaccination.
The results suggest that a second vaccination is important in regions of high HIV prevalence to protect HIV-infected children, maintain 'herd' or group immunity and to bolster measles elimination efforts.
Measles, caused by a virus of the Paramyxovirinae family, remains an important cause of child mortality in sub-Saharan Africa, says William Moss, lead author of the study and an associate professor at the US-based Bloomberg School of Public Health at the Johns Hopkins University.
According to the researchers, the measles virus only needs a small number of susceptible children to cause outbreaks, so it is important that as many children as possible have immunity to the virus.
The researchers studied the immune response to the measles vaccine in 696 healthy and HIV-infected children, aged 2-8 months.
Within six months of measles vaccination at nine months of age, 88 per cent of HIV-infected children developed protective antibody levels, as did 94 per cent of children who did not have HIV.
But after a further 27 months, only half of the surviving HIV-infected children maintained antibody levels high enough to protect against measles, versus almost 90 per cent of healthy children.
The results of the study show that sufficient resources must be invested in maintaining high levels of population immunity against measles in regions of high HIV prevalence, says Moss.
The World Health Organization already recommends vaccinating children for measles a second time, either through repeated immunisation campaigns or a routine second dose delivered through the primary healthcare system.
But despite recent progress in measles control, obstacles to eliminating the disease exist, including insufficient resources and lack of political will.
'The study is important because it shows the impact HIV has on the nation and sends a message to the government to double its effort on measles vaccination,' Chansa Nkonga Mwangilwa, from Zambia's University Teaching Hospital and co-author of the study told SciDev.Net.
The authors recommend that additional research be conducted to determine the duration of measles immunity in HIV-infected children who are receiving antiretroviral therapy, and their response to revaccination against measles.
研究称感染艾滋病儿童需加倍注射麻疹疫苗
[赞比亚卢萨卡]一项新的研究表明，感染了艾滋病病毒的儿童可能需要重复接种麻疹疫苗，从而保持有效的抗体浓度。
这项在赞比亚进行的研究发表在下周（8月1日）出版的《传染病杂志》上。它发现与健康儿童相比，感染艾滋病病毒的儿童在初次接种麻疹疫苗之后不太容易保持有效的抗体浓度。
这项结果表明，为了保护感染艾滋病病毒的儿童，在艾滋病高流行的地区为儿童接种第二针麻疹疫苗是很重要的。
该研究的主要作者、美国约翰·霍普金斯大学布隆伯格公共卫生学院的William Moss说，麻疹是由副黏液病毒亚科的一种病毒引起的，它仍然是撒哈拉以南非洲导致儿童死亡的一个重要因素。
这组科学家研究表明，麻疹病毒只需要一少部分易感儿童就能导致麻疹暴发，因此让尽可能多的儿童对麻疹有免疫力是很重要的。
这组科学家研究了696名2至8个月的健康儿童和感染艾滋病的儿童对麻疹疫苗的免疫应答。
9个月大的儿童在接种麻疹疫苗之后的6个月内，88%的感染艾滋病的儿童产生了有效的抗体浓度，而健康儿童的数字是94%。
但是又经过27个月后，幸存的感染艾滋病的儿童中只有一半的抗体浓度维持在有效水平，而健康儿童的数字几乎是90%。
Moss说，这项研究的结果表明，在艾滋病高流行区，必须投入充足的资源用于维持对麻疹免疫的高水平人群。
世界卫生组织已经建议为儿童两次接种麻疹疫苗。这些儿童可以通过重复免疫接种运动，或者通过基本卫生保健系统常规接种第二针疫苗。
但是，尽管近年来麻疹防控取得了进展，妨碍消灭该病的障碍仍然存在，这包括资源不足和缺乏政治意愿。
赞比亚大学教学医院的Chansa Nkonga Mwangilwa是这项研究的共同作者，他告诉本网站说：“这项研究很重要，因为它表明了艾滋病对该国的影响，并且给政府送去了一个信号，即需要让麻疹免疫接种的努力加倍。”
这组作者建议开展进一步的研究，从而确定接受抗逆转录病毒治疗的艾滋病儿童对麻疹的免疫力能维持多久，以及他们对重复接种麻疹疫苗的响应情况。
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