Adis, a Wolters Kluwer Business, Auckland, New Zealand.
Drugs. 2011 Aug 20;71(12):1591-622. doi: 10.2165/11206860-000000000-00000.
Live attenuated influenza vaccine (LAIV) is an intranasally administered trivalent, seasonal influenza vaccine that contains three live influenza viruses (two type A [H1N1 and H3N2 subtypes] and one type B). LAIV was effective in protecting against culture-confirmed influenza caused by antigenically matched and/or distinct viral strains in children aged ≤71 months enrolled in three phase III trials. LAIV was superior to trivalent inactivated influenza vaccine (TIV) in protecting against influenza caused by antigenically-matching viral strains in a multinational phase III trial in children aged 6-59 months. LAIV was also significantly more effective than TIV in decreasing the incidence of culture-confirmed influenza illness in two open-label studies (in children with recurrent respiratory tract illnesses aged 6-71 months and in children and adolescents with asthma aged 6-17 years). LAIV did not differ significantly from placebo in preventing febrile illnesses in adults (primary endpoint) enrolled in a phase III trial. However, LAIV significantly reduced the incidence of febrile upper respiratory tract illnesses (URTI), severe febrile illnesses, febrile URTI-related work absenteeism and healthcare provider use. In another well designed trial in adults, LAIV significantly reduced the incidence of symptomatic, laboratory-confirmed influenza compared with placebo (but not intramuscular TIV). LAIV was generally well tolerated in most age groups, with the majority of adverse events being mild to moderate in severity, and runny nose/nasal congestion being the most common. In a large phase III trial, LAIV, compared with TIV, was associated with an increased incidence of medically significant wheezing in vaccine-naive children aged <24 months and an increased incidence of hospitalization in children aged 6-11 months; LAIV is not approved for use in children <24 months. LAIV was not always associated with high rates of seroconversion/seroresponse, particularly in older children and adults, or in subjects with detectable levels of haemagglutination-inhibiting antibodies at baseline. However, LAIV did elicit mucosal (nasal) IgA antibody responses and strong cell-mediated immunity responses. Only one confirmed case of LAIV virus transmission to a placebo recipient (who did not become ill) occurred in a transmission study conducted in young children. The immunogenic response to LAIV in young healthy children was not affected by concomitant administration with other commonly administered childhood vaccines. In conclusion, intranasal LAIV seasonal influenza vaccine is effective and well tolerated in children, adolescents and adults. LAIV was more effective than TIV in children, although this advantage was not seen in adults. In the US, LAIV is indicated for the active immunization of healthy subjects aged 2-49 years against influenza disease caused by virus subtypes A and type B contained in the vaccine.
流感减毒活疫苗（LAIV）是一种鼻内给药的三价、季节性流感疫苗，含有三种活流感病毒（两种 A 型[H1N1 和 H3N2 亚型]和一种 B 型）。LAIV 已被证明可有效预防在三期临床试验中接种的≤71 个月龄儿童中由抗原匹配和/或不同病毒株引起的经培养确认的流感。LAIV 在保护 6-59 个月大的儿童免受抗原匹配病毒株引起的流感方面优于三价灭活流感疫苗（TIV），在一项多中心三期临床试验中。LAIV 在两项开放性研究（在 6-71 个月大的复发性呼吸道疾病儿童和 6-17 岁的哮喘儿童和青少年中）中也显著降低了经培养确认的流感疾病发病率。LAIV 在预防接种三期临床试验中的成年发热性疾病（主要终点）方面与安慰剂无显著差异。然而，LAIV 显著降低了发热性上呼吸道疾病（URTI）、严重发热性疾病、发热性 URTI 相关旷工和医疗保健提供者使用的发病率。在另一项设计良好的成人试验中，与安慰剂相比，LAIV 显著降低了有症状、实验室确认的流感的发病率（但不是肌内 TIV）。LAIV 在大多数年龄组中通常耐受性良好，大多数不良事件为轻度至中度严重，且流鼻涕/鼻塞为最常见的。在一项大型三期试验中，与 TIV 相比，LAIV 与 24 个月以下疫苗初免儿童中医学意义上的喘息发病率增加和 6-11 个月大儿童的住院率增加相关；LAIV 不批准用于 24 个月以下的儿童。LAIV 并不总是与高血清转化率/血清反应率相关，特别是在年龄较大的儿童和成人中，或在基线时具有可检测水平的血凝抑制抗体的受试者中。然而，LAIV 确实引起了黏膜（鼻）IgA 抗体反应和强烈的细胞介导免疫反应。在对幼儿进行的一项传播研究中，只有一例经确认的 LAIV 病毒传播给安慰剂接受者（未患病）的病例。在年轻健康儿童中，LAIV 的免疫原性反应不受与其他常用儿童疫苗同时给药的影响。总之，鼻内 LAIV 季节性流感疫苗在儿童、青少年和成年人中有效且耐受性良好。LAIV 在儿童中的效果优于 TIV，尽管在成年人中未观察到这种优势。在美国，LAIV 用于主动免疫 2-49 岁健康人群，预防疫苗中包含的 A 型和 B 型病毒引起的流感疾病。
