Even as French pharma giant Sanofi has stalled development work on a Zika virus vaccine candidate, India is pushing ahead with two vaccine candidates against the virus that continues to cause havoc across the world, and could cause Alzheimer’s style symptoms in adults, reports The Pharma Letter’s India correspondent.
Hyderabad-based Bharat Biotech has two Zika vaccine candidates in development: one is a recombinant vaccine and another inactivated vaccine.The biotech company has developed an inactivated virus vaccine with the African MR 766 strain. Preliminary studies have shown 100% efficacy against mortality and disease in animals.
The Indian bio-therapeutic manufacturer began work on the Zika virus in 2015. It had to import samples of the virus in order to conduct experiments, as they were none on Indian soil at that time. This essentially placed India nearly 18 months ahead of the rest of the world, with the development of a Zika vaccine.
Still an emergency
Though the global race for a Zika vaccine could be slowing down, and the World Health Organization downgraded its global health emergency status in November 2016, at Bharat Biotech there is no slowdown in urgency to bring a promising vaccine.
Bharat Biotech reported on two doses of the vaccine “with homotypic MR 766 and the heterotypic FSS 13025 Zika strains in the Type I and Type II interferon deficient AG129 mice.” The results of the study showed how two doses were found to protect mice against Zika virus seven days after the second vaccination.
Stating that vaccination for Zika is a public health priority due to serious congenital and neuropathological abnormalities observed as a sequelae of the virus infection in recent epidemics, the company has said the vaccine candidate was found to confer 100% protection against infection caused by an Asian Zika virus strain as well as the African Zika virus strain.
Zika was declared a public health emergency by the WHO in early 2016. “This continues to be a public health emergency requiring a united response,” said an official, adding that there were reports about some babies born in South America with microcephaly last year. Though there was a huge debate whether the birth deformity was a direct consequence of the Zika virus or Larvicide, the fact that so many babies were born with the deformity following the outbreak of the Zika virus, in Brazil alone, was no coincidence, the official added.
Bharat Biotech’s vaccine was developed using the African strain of the virus. The official added that the company would aim to scale up the characterization of the vaccine.
“Our interest in the Zika virus stems from the fact that it was an obscure virus when we started the project, and that clinical features at an early stage of infection are indistinguishable from either that of Dengue and Chikungunya,” he said.
Given that the Aedes aegypti, the primary mosquito that carries the Zika virus, is said to also transmit Chikungunya and Dengue viruses with one bite, Indian pharma companies are looking to treat the co-infection, even as some concentrate on the other two viruses.
Several candidates
Reports indicate there are approximately 38 Zika vaccines in early development around the world.
The USA’s National Institute of Allergy and Infectious Diseases (NIAID) has said multiple research approaches are key to pandemic preparedness, and that the ‘prototype pathogen’ approach can shorten the time needed to create vaccines using platform-based methods.
This approach involves studying the characteristics of categories or families of pathogens, such as the family of viruses that contains Dengue, West Nile and Zika viruses, and developing vaccines for the category ahead of time.
GlaxoSmithKline had announced in July 2016 it is working with the National Institutes of Health to develop a Zika virus vaccine. The US government has also partnered with GlaxoSmithKline and Takeda on two separate Zika vaccine candidates.
Inovio Pharmaceuticals, a Pennsylvania based company, has reported positive safety and immune response results from a multi-center Phase I trial of a vaccine against the Zika virus.
Austrian’s Themis Bioscience, a company specialized in vaccine development, announced a £3 million ($4 million) funding received by the innovation agency of the UK, Innovate UK.
The company’s initial vaccine candidates are currently being developed against Chikungunya and Zika. The funds are earmarked for the development of the company’s prophylactic Chikungunya vaccine candidate that currently is tested in three Phase II trials.
In the wake of the development of the Chikungunya vaccine and supported with another £1 million grant by Innovate UK last year, the company has also succeeded in advancing the development of a live attenuated recombinant Zika vaccine. Currently, this is being tested in a Phase I clinical trial at the Medical University of Vienna, Austria.
In India, Sun Pharmaceutical and The National Institute of Virology in Pune, an institution of the Indian Council of Medical Research, Ministry of Health and Family Welfare, teamed up this June to test phytopharmaceutical, biologic and chemical entities developed by Sun Pharma against Zika, Chikungunya and Dengue viruses.
Because the Zika virus and Dengue virus are related flaviviruses, their homologous proteins and nucleic acids can cause cross-reactions and false-positive results in molecular, antigenic, and serologic diagnostics. Researchers from India, Spain, Columbia and the USA have also developed an easy-to-use rapid diagnostic test for Zika and Dengue viruses.
Bharat Biotech too had spotted the similarities between the early stages of Zika, Dengue, and Chikungunya, and filed a patent for its two vaccine candidates.
Recently, Bharat Biotech developed a vaccine for typhoid with an efficacy of 87% for babies, children and adults under real-life conditions. The results of the human clinical trial, conducted by Andrew Pollard of the Oxford Vaccine Group, were published in the Lancet.
Tests ongoing
India continues to test for the Zika virus at several of its laboratories. Human surveillance network for the Zika virus disease has also been set up by the Indian Council of Medical Research (ICMR).
The Reproductive and Child Health division of the Health Ministry has initiated several programs on New Born Birth Defect (NBBD) screening and still-birth surveillance. The current NBBD registry focuses on reporting of eight externally visible birth defects including microcephaly from 55 Medical Colleges of the country. The Ministry of Health is also collaborating with ICMR for linking Zika testing in microcephaly cases.
With regards to alternate strategies for vector control in India, ICMR in collaboration with the Monash University, Australia, is initiating work on Wolbachia based vector control for Aedes mosquitoes.
Source: The Pharma Letter
