德国慕尼黑工业大学: 新的乙肝治疗疫苗可能最终提供一种治疗方法
Hepatitis B: New Therapeutic Vaccine May At Last Offer A Cure

　

德国科学家正在研究一种新的乙肝治疗疫苗，这种疫苗可以使乙肝变得可以治愈。事实上，全世界大约有2.6亿人患有慢性乙型肝炎，目前尚无治愈方法。尽管有一种有效的乙肝疫苗，但每年仍有88万人死于乙肝病毒感染。特别是，儿童早期感染可导致慢性疾病。
 
虽然现有的抗病毒药物可以抑制病毒的生长，但它们不能治愈这种疾病。当停止治疗时，乙肝病毒将重新出现。原因是一种小型的环状病毒DNA沉积在被感染的肝细胞细胞核中，这使得病毒在停止治疗后能够存活并重新繁殖。即使病毒载量很低，患有慢性乙型肝炎的患者也有患肝硬化或肝癌的风险。
 
因此，迫切需要新的治疗方法。慕尼黑工业大学(TUM)的Ulrike Protzer和德国负责研究环境健康问题的机构Helmholtz Zentrum Munchen的Ulrike解释说:“我们已经开发出一种治疗性疫苗，通过连续两次接种，可以首次提供康复的机会。”
 
科学家们已经成功地进行了临床前试验。但是，现在，在与其他研究机构的一个联合项目中，第一个关于人类的临床研究正在准备中。对于这种创新的治疗性疫苗，两种不同的成分被结合在一起:在第一步中——被描述为最初的一步——特异性乙肝蛋白被用作抗原，以触发中和抗体的形成，并为它们的使用准备T细胞。随后，利用人体自身的防御反应，通过使用与乙型肝炎病毒基因序列结合的痘病毒载体来增强防御反应——即增强步骤。据说这种病毒载体可以增强特定T细胞对病毒的抵抗能力。T细胞是人体重要的免疫细胞，可以杀死受病毒感染的细胞。
 
在临床前模型中，这种“启动疫苗”是成功的。病毒载量和在血液中的传播减少，T细胞形成，科学家能够中和受影响的肝细胞。这说明该方法适合于解决病毒持续存在的问题，从而治愈该病。进一步开发疫苗还需要更多的研究和试验。
 
根据美国疾病控制与预防中心(CDC)的数据，在美国有85万到220万人患有慢性乙型肝炎。

　

Hepatitis B: New Therapeutic Vaccine May At Last Offer A Cure

 

German scientists are working on a new therapeutic vaccine against hepatitis B that could make the disease curable. Indeed, around 260 million people worldwide suffer from chronic hepatitis B, for which there is currently no cure. Although there is an effective hepatitis B vaccine, 880,000 people die every year from the hepatitis B virus infection. In particular, infection in early childhood leads to a chronic disease.

 

While the available antiviral agents can stem the growth of the viruses, they can not cure the disease. When treatment is discontinued, the hepatitis B viruses will re-emerge. The reason is a small, circular form of viral DNA that is deposited in the nucleus of infected liver cells, which allows the virus to survive and repopulate when treatment ceases. Even with a low viral load, patients suffering from chronic hepatitis B carry the risk of developing liver cirrhosis or liver cancer.

 

Thus, new curative treatment approaches are urgently needed. “We have developed a therapeutic vaccine that could offer a chance of recovery for the first time through two successive vaccinations,” explains Ulrike Protzer from the Technical University of Munich (TUM) and the Helmholtz Zentrum München, a German agency responsible for studying environmental health issues.

 

The scientists have already successfully performed pre-clinical tests. But, now, in a joint project with other research institutions, a first clinical study on humans is to be prepared. For the innovative therapeutic vaccine, two different components are combined: in a first step — described as the prime step — specific hepatitis B proteins are used as antigens to trigger the formation of neutralizing antibodies and to prepare T cells for their use. Then using the body’s own defense subsequently, the defense reaction is boosted — the boosting step — by the use of a poxvirus vector, which is incorporated in the gene sequences of the hepatitis B virus. This viral vector is said to enhance the production of specific T cells against the virus. The T cells are important immune cells in our body that can kill cells affected by viruses.

 

In pre-clinical models, this “prime-boost vaccine” was successful. The viral load and spread in the blood was reduced, T cells were formed and scientists were able to neutralize the affected liver cells. This showed that the approach is suitable to solve the problem of virus persistence and thus to cure the disease. More research and trial are needed to develop the vaccine further.

 

According to the Centers for Disease Control and Prevention (CDC),  between 850,000-2.2 million people suffer from chronic hepatitis B in the United States.

 

https://www.thetalkingdemocrat.com/2018/03/hepatitis-b-vaccine-scientists-cure/