First Human Trials For Nipah Virus Vaccine

GS Paper III Technology and Development

Context:

Scientists at the University of Oxford U.K. have launched first-in-human Nipah Virus Vaccine trials for the Nipah virus disease.

Nipah Virus Vaccine Name: ChAdOx1 NipahB vaccine.
The vaccine uses the ChAdOx1 platform, the same that was used for the Oxford/AstraZeneca COVID-19 vaccine.
Trail: It will consist of 51 people aged 18 to 55, for a period of the next 18 months, led by the Oxford Vaccine Group.

They use a harmless virus to smuggle the instructions for making antigens from the disease-causing virus into cells, triggering protective immunity against it.
It differs from most conventional vaccines in that they don’t actually contain antigens, but rather use the body’s own cells to produce them.
Mechanism: It uses a modified virus (the vector) to deliver genetic code for antigen, in the case of COVID-19 spike proteins found on the surface of the virus, into human cells.
Vector infects cells and instructs them to make large amounts of antigen, which then trigger an immune response, the vaccine mimics what happens during natural infection with certain pathogens – especially viruses.

About: It belongs to a family of paramyxoviruses.
First identified: In 1998 in Malaysia and Singapore in an outbreak among pig farmers.
Carriers: Fruit bats of the family Pteropodidae acts as a natural host of the virus.

Transmission of Nipah Virus

Transmission of Nipah Virus

Outbreaks: Outbreaks have occurred in countries in Asia, including Singapore, Malaysia, Bangladesh and India with Kerala seeing annual outbreaks. Nature of Transmission:
- It is zoonotic in nature ( transmitted from animals to humans)

Priority Disease for WHO Research and Development Blueprint:

About: It is a WHO tool distinguishing the diseases which pose the greatest public health risk due to their epidemic potential and whether there is sufficient countermeasures available.
Objective: To ensure efforts under WHO’s R&D Blueprint are focused and productive, a list of diseases and pathogens are prioritized for R&D in public health emergency contexts.
Examples: COVID-1, Ebola virus, Severe Acute Respiratory Syndrome (SARS), Nipah, Rift Valley fever, Zika and Disease X.

- Unprotected exposure to secretions or tissues of a sick animal (Eg: Malaysia)
- Consumption of fruits or fruit products (such as raw date palm juice) contaminated with urine or saliva from infected fruit bats was the most likely source of infection ( Example: cases in Kerala)
Human-to-human transmission of Nipah virus has also been reported among family and caregivers of infected patients. (Example: Siliguri, India in 2001, 75% of cases occurred among hospital staff or visitors.)
Infection: Human infections range from asymptomatic infection to acute respiratory infection (mild, severe), and fatal encephalitis progressing to coma within 24 to 48 hours.
- The incubation period (interval from infection to the onset of symptoms) is believed to range from 4 to 14 days.
Diagnosis: The main tests used are real-time polymerase chain reaction (RT-PCR) from bodily fluids and antibody detection via enzyme-linked immunosorbent assay (ELISA).
Treatment: There are currently no drugs or vaccines specific for Nipah virus infection.
WHO Status: WHO has identified Nipah as a priority disease for the WHO Research and Development Blueprint saying it has pandemic potential.