Jani Jagrati V, Holm-Hansen Carol, Mussá Tufária, Zango Arlinda, Manhiça Ivan, Bjune Gunnar, Jani Ilesh V
Department of Immunology, Instituto Nacional de Saúde, Mozambique.
BMC Public Health. 2008 Nov 12;8:386. doi: 10.1186/1471-2458-8-386.
The optimum age for measles vaccination varies from country to country and thus a standardized vaccination schedule is controversial. While the increase in measles vaccination coverage has produced significant changes in the epidemiology of infection, vaccination schedules have not been adjusted. Instead, measures to cut wild-type virus transmission through mass vaccination campaigns have been instituted. This study estimates the presence of measles antibodies among six- and nine-month-old children and assesses the current vaccination seroconversion by using a non invasive method in Maputo City, Mozambique.
Six- and nine-month old children and their mothers were screened in a cross-sectional study for measles-specific antibodies in oral fluid. All vaccinated children were invited for a follow-up visit 15 days after immunization to assess seroconversion.
82.4% of the children lost maternal antibodies by six months. Most children were antibody-positive post-vaccination at nine months, although 30.5 % of nine month old children had antibodies in oral fluid before vaccination. We suggest that these pre-vaccination antibodies are due to contact with wild-type of measles virus. The observed seroconversion rate after vaccination was 84.2%.
These data indicate a need to re-evaluate the effectiveness of the measles immunization policy in the current epidemiological scenario.
麻疹疫苗接种的最佳年龄因国家而异，因此标准化的疫苗接种计划存在争议。虽然麻疹疫苗接种覆盖率的提高已使感染流行病学发生了重大变化，但疫苗接种计划并未得到调整。相反，已采取措施通过大规模疫苗接种运动减少野生型病毒传播。本研究估计了莫桑比克马普托市6个月和9个月大儿童中麻疹抗体的存在情况，并使用非侵入性方法评估了当前的疫苗接种血清转化率。
在一项横断面研究中，对6个月和9个月大的儿童及其母亲进行口腔液中麻疹特异性抗体筛查。所有接种疫苗的儿童在免疫后15天被邀请进行随访，以评估血清转化率。
82.4%的儿童在6个月时失去了母体抗体。大多数儿童在9个月接种疫苗后抗体呈阳性，尽管30.5%的9个月大儿童在接种疫苗前口腔液中就有抗体。我们认为这些接种前抗体是由于接触野生型麻疹病毒所致。接种疫苗后观察到的血清转化率为84.2%。
这些数据表明有必要在当前的流行病学情况下重新评估麻疹免疫政策的有效性。
