Chikungunya virus vaccine (Valneva)

在今年5月的时候，FDA和CDC发表了一项联合建议，建议在对上市后安全性报告进行调查期间，60岁及以上的个体应暂停使用基孔肯雅病毒疫苗Ixchiq。而今年8月初的时候，疫苗商Valneva又宣布FDA已经解除对老年人的使用暂停，允许恢复接种，但要求实施更严格监管。 看似峰回路转，实则一波三折，最近FDA又把Ixchiq全线暂停了，这次暂停“立即生效，要求疫苗商Valneva公司在美国境内停止销售和运输”Ixchiq疫苗。 Ixchiq Ixchiq（VLA1553）是一种减毒活疫苗，通过删除基孔肯雅病毒（CHIKV）基因组的关键部分，来降低病毒毒性同时保留免疫原性。 然而，即便是减毒版仍可能引起与天然基孔肯雅病毒感染相似的症状，在接种疫苗后的前几周，部分人血液中可能会测到构成 Ixchiq疫苗的减毒版病毒，类似于基孔肯雅病毒感染初期的情况。在2023年上市时，FDA 要求疫苗商 Valneva 进行上市后研究，以评估疫苗的潜在长期风险。 现在结果来了，问题很严重，一些上市后报告包括与基孔肯雅病严重并发症一致的不良事件，其中21例需住院治疗，3例死亡，包括一例因脑炎死亡的病例，该病例已被证实与疫苗接种相关。 Ixchiq的开发其实很早就开始了，2013年开始I期临床，2019年III期临床，2023年11月，FDA基于III期试验的免疫原性数据（替代终点）加速批准Ixchiq，适用于18岁及以上“感染风险增加”人群。 目前并不是很清楚为何此前这一问题在临床过程中没有暴露，Valneva此前发布的安全性数据均表示良好。猜测和疫苗副作用本身与基孔肯雅病毒相似有关，考虑到临床在基孔肯雅疫情爆发的巴西进行，或许临床试验本身存在大量误诊……将疫苗副作用误诊为病毒感染。 参考来源： https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-and-cdc-recommend-pause-use-ixchiq-chikungunya-vaccine-live-individuals-60-years-age-and-older https://www.fda.gov/vaccines-blood-biologics/ixchiq · · · · · · · ·

AUDIENCE: Patient, Health Care Professional, Pharmacy, Cardiology, Neurology, Internal Medicine, Family Practice, Travel Clinics UPDATE: On August 22, 2025, the US FDA’s Center for Biologics Evaluation and Research (CBER) has suspended the biologics license for Valneva Austria GmbH’s Ixchiq (Chikungunya Vaccine, Live). This vaccine was initially approved by FDA under the accelerated approval pathway in November of 2023 for the prevention of disease caused by the chikungunya virus (CHIKV) in individuals 18 years of age and older who are at increased risk of exposure to CHIKV. CBER’s decision is based on serious safety concerns related to the vaccine, which appears to be causing chikungunya-like illness in vaccine recipients. There has been one death from encephalitis directly attributable to the vaccine (CSF PCR was + for the vaccine strain of the virus) and over 20 reported serious adverse events that were consistent with chikungunya-like illness. Reported serious adverse events have included 21 hospitalizations and 3 deaths. Furthermore, the clinical benefit of the vaccine has not yet been verified in confirmatory clinical studies. CBER’s benefit-risk analysis broadly shows the vaccine does not have benefits outweighing risks, under most plausible scenarios. For these reasons, CBER believes this vaccine is not safe and that continued administration to the public would pose a danger to health. On August 6, 2025, FDA lifted a pause in the use of Ixchiq in individuals 60 years of age and older and approved required updated labeling for Ixchiq, including revising the indication, and adding limitations of use and enhanced warnings and precautions to reflect serious postmarketing adverse reactions including hospitalizations and encephalitis in a person who died, with risk noted for individuals 65 years and older with chronic medical conditions. On May 9, 2025, FDA issued a safety communication informing the public that the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) jointly recommended a pause in the use of Ixchiq (Chikungunya Vaccine, Live) in individuals 60 years of age and older while the Agencies undertook an investigation of postmarketing reports of serious adverse events, including neurologic and cardiac events, in individuals who have received the vaccine. The November 9, 2023, approval of Ixchiq included a warning in the Prescribing Information informing that the vaccine may cause severe or prolonged chikungunya-like adverse reactions. Ixchiq contains a live, weakened version of the chikungunya virus and may cause symptoms in the vaccine recipient similar to those experienced by people who have chikungunya. BACKGROUND: Ixchiq contains a live, weakened version of the chikungunya virus and may cause symptoms similar to those of chikungunya disease. Some of the postmarketing reports include adverse events that are consistent with severe complications of chikungunya disease, resulting in hospitalization; one person died from encephalitis. Continuous monitoring and assessment of the safety of all vaccines remains an FDA priority. Suspected adverse events may be reported to the Vaccine Adverse Event Reporting System ( VAERS ), which is co-managed by FDA and CDC. [ FDA Safety Communication - 08/22/2025] Content current as of: 08/25/2025 Legal Disclaimer: EIN Presswire provides this news content "as is" without warranty of any kind. We do not accept any responsibility or liability for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this article. If you have any complaints or copyright issues related to this article, kindly contact the author above.