News

Study sheds light on how Zika causes nerve disorder

The Zika outbreak that swept through the Americas in 2015 and 2016 showed the virus can, in rare cases, lead to Guillain-Barré, an autoimmune disease in which the body attacks itself in the aftermath of an infection.

(Reuters)

CHICAGO – A new study sheds light on how the mosquito-borne Zika virus caused a rare neurological disorder, and the findings may have implications for companies that are active on Zika vaccines, U.S. researchers said on Wednesday.

The Zika outbreak that swept through the Americas in 2015 and 2016 showed the virus can, in rare cases, lead to Guillain-Barré, an autoimmune disease in which the body attacks itself in the aftermath of an infection.

Since the Zika virus attacks nerve cells, the scientists were not sure if it’s Guillain-Barre cases they had seen in Zika patients were caused by an autoimmune response to the Zika infection or a direct attack by the virus on nerve cells.

In pregnant women the virus infects the fetal brain cells, resulting in the birth defect known as microcephaly.

SEASONAL FLU KILLS MORE THAN PREVIOUSLY THOUGHT, STUDY FINDS

For the study of the nerve disorder, Dr. Tyler Sharp of the U.S. Centers for Disease Control and Prevention’s Dengue Branch in San Juan, and colleagues in Puerto Rico examined the rare case of a 78-year-old man from San Juan, which were infected with Zika in 2016, developed Guillain-Barre and then died.

An autopsy showed inflammation and erosion of the protective sheath known as myelin in two nerves, but no evidence of the Zika virus in the nerve cells.

“In this case, it just seems antibodies that led to the destruction of myelin sheath,” said Sharp, whose study was published in Emerging Infectious diseases, the CDC’s public health journal.

Although only a single case, Sharp said that the proposed mechanism is that causes the Guillain-Barré after a Zika infection was the same as in the other cases of the nerve disease.

Sharp said the study brought out a caution flag, however, for companies testing experimental Zika vaccines. Although Guillain-Barré usually occurs in the aftermath of an infection, it is known to be performed in response to a vaccine.

“Vaccine manufacturers need to think about the Guillain-Barré as a possible outcome of vaccination against Zika,” he said.

Different companies develop Zika vaccines, including Takeda Pharmaceutical Co, which said earlier this month began an early-stage safety trial. The results are expected next year.

Dr. Rajeev Venkayya, president of Takeda’s Global Vaccine Business Unit, had not seen the study, but said in a telephone interview that the company “would be looking for any problems with the security, including the Guillain-Barré-syndrome in the clinical studies.

Follow us

Don't be shy, get in touch. We love meeting interesting people and making new friends.

Most popular