INFLUENZA VACCINE DEVELOPMENT AND USE

近年来，B型流感病毒在人类群体中出现 B/Victoria/2/87-like和B/Yamagata/16/88- B/Yamagata样病毒的漂移已被鉴定为 去年的一组雪貂抗血清，并提出了 疫苗成分是否需要进一步改变的问题。 为了确定人类对新的B/Yamagata样变异体的反应，来自23个人的血清 儿童和30名成人接种了含有 检测了流感病毒B/Yamagata/16/88的抗原。 Kong/22/89(B/Yamagata的一种免疫学上可区分的变体)， 免疫后中和抗体几何平均滴度(GMT) 只有大约一半的人对抗疫苗病毒(互惠 B/Yamagata的GMT=344，B/香港的157)。在的子集中 没有免疫接种的儿童差异更明显。 (B/Yamagata的GMT=473，B/香港的GMT=141)。针对一组 B/Yamagata类病毒的变种甚至漂移得更远 免疫学上比B/香港(巴拿马/45/90，曼谷/163/90，伊利诺伊州 2005和德克萨斯州VC-11037)，成人免疫后血清由 血凝抑制(以洗涤剂裂解病毒为抗原) GMT无差异(B/Yamagata为218，B/巴拿马为218， B/伊利诺伊州，230个B/德克萨斯州，179个B/曼谷)。这些结果 建议成年人将得到足够的保护，免受新的 与B/Yamagata相关的漂移的B型流感病毒株，但儿童， 尤其是那些以前很少或从未接触过B型流感的人 抗原，可能不是预防感染的最佳选择。数据 表明成人的疫苗策略可能不适用于儿童。

Influenza B viruses have been represented in human populations in recent years by two divergent strains, B/Victoria/2/87-like and B/Yamagata/16/88- like viruses.Drift in the B/Yamagata-like viruses has been identified by a panel of ferret antisera during the past year and has raised the question of need for further alterations in vaccine composition.In order to determine human responses to new B/Yamagata-like variants, sera from 23 children and 30 adults who were immunized with vaccines containing the antigens of influenza virus B/Yamagata/16/88 were tested.Against B/Hong Kong/22/89 (an immunologically distinguishable variant of B/Yamagata), post-immunization geometric mean titers (GMT) of neu-tralizing antibodies were only approximately half those against the vaccine virus (reciprocal GMT = 344 for B/Yamagata vs. 157 for B/Hong Kong). Among the subset of children who were immunologically unprimed the disparity was more marked (GMT = 473 for B/Yamagata vs. 141 for B/Hong Kong). Against a panel of variants of B/Yamagata-like viruses that have drifted even further immunologically than B/Hong Kong (Panama/45/90, Bangkok/163/90, Illinois 2005, and Texas VC-1 1037), adult postimmunization sera tested by hemagglutination inhibition (with detergent split virus as antigen) showed no difference in GMT (218 for B/Yamagata, 218 for B/Panama, 218 for B/Illinois, 230 for B/Texas, and 179 for B/Bangkok). These results suggest that adults would be adequately protected against the newly drifted influenza B strains related to B/Yamagata, but that children, particularly those with little or no previous exposure to influenza B antigens, might be suboptimal for protection against infection. The data suggest that vaccine strategies for adults may be inadequate for children.