A double antibody to defeat Zika virus

The prestigious scientific journal Cell today published a study resulting from a collaboration between the Institute for Research in Biomedicine affiliated to Universita’ della Svizzera Italiana, Humabs Biomed SA and the Duke National University of Singapore. The researchers developed an innovative “double” antibody that protects from Zika virus infection.

Zika, present in 84 nations worldwide, has a remarkable ability to change its structure (mutate) to escape the response of the immune system. The problem was confronted and solved joining together, in a single molecule, two antibodies that block two different parts of the virus at the same time. Pre-clinical studies show that the “double” antibody, “bispecific” in technical terms, efficiently protects against Zika and prevents the virus mutation. The antibody has properties that make it an ideal therapeutic candidate.

Luca Varani PhD, group leader at the Institute for Research in Biomedicine and co-author of the study said: ”Our double antibody prevents Zika from evading the immune system, a problem difficult to solve with a single antibody. We characterized the interaction between virus and antibody at different levels, spanning from atomic interactions to the molecular and cellular level. A combination of computational and experimental techniques was instrumental to study the atomic interactions between Zika virus and antibody”. The IRB is one of the rare laboratories where high resolution magnetic resonance is used to characterize antibodies.

According to Davide Corti PhD, co-author of the study and Chief Scientific Officer of Humabs Biomed SA, a subsidiary of Vir Biotechnology Inc.:”Zika virus infection has turned into a public health threat, particularly due to its association with congenital birth defects. Vaccine development may encounter some difficulties and it is important to develop alternative therapeutic approaches. The pre-clinical data we published show good efficacy; we intend to explore alternative delivery mechanisms for the antibody that could make it more cost effective and thus more accessible to the parts of the world most in need for cures for this disease”.

Associate Professor Shee Mei Lok from Duke-NUS added: “The FIT-1 antibody has immense potential to be developed as a therapeutic for the treatment and prevention of Zika virus infection in adults and pregnant women. Hopefully, clinical trials can be accelerated so that the FIT-1 antibody may be used in future outbreaks, as well as to tackle emergency cases of Zika infection in pregnant women.”

“We are very proud of this scientific result, obtained also with the financial contribution from the cantonal office of economic development, part of the program for support of innovation.” Said Filippo Riva, General Director of Humabs Biomed.

About Zika Virus

Zika belongs to the flavivirus class, which includes also Dengue and West Nile virus. Zika virus is spread by mosquitoes and has reached large parts of the tropical and subtropical regions of the world, including parts of the United States. The World Health Organization (WHO) declared in early 2016 a state of Public Health Emergency of International Concern (PHEIC) and predicted that 3-4 million people would become infected annually, 1.5 million of these in Brazil alone. While the symptoms of Zika virus infection can be absent or generally mild, the virus appears to invade the neural tissue of the fetus, leading to microcephaly and other neural defects in offspring in up to 13% of cases. The virus can also be spread by bodily fluids, including semen, and so can also be sexually transmitted. While attempts have been made to reduce the spread of the virus by spraying with insecticides, there are currently no vaccines or treatments against Zika, and WHO has declared a need for a long-term approach to combatting this infection. Thus, there is an urgent need to develop therapies to treat this rapidly spreading disease.