A novel finding conducted recently by icddr,b scientists and partners published in the journal Tropical Medicine and Infectious Disease has confirmed the transfer of humoral immunity against Nipah virus (NiV) from mother to newborn baby for the first time.
The paper described novel information on the vertical transfer of immune properties.
According to the World Health Organization, the mortality rate for NiV is estimated at 40% to 75%, and in Bangladesh, it is about 71%.
The survivors of NiV infection suffer from severe neurological complications. Moreover, there is a high chance that these symptoms worsen progressively when a survivor becomes pregnant.
In January 2020, a baby girl aged below five years and her mother from Faridpur district of Bangladesh were infected with NiV. Both had a history of consuming raw date palm sap and were diagnosed as confirmed NiV cases.
The daughter died, while the mother survived with significant residual neurological impairment.
She conceived in November 2021 and was under thorough antenatal follow-up by the National Nipah surveillance authority.
A healthy male baby was born in August 2022.
As part of the follow-up, specimens were collected and tested for NiV infection at the reference laboratory to exclude vertical transmission.
Although tested negative for anti-Nipah IgM and PCR for NiV, a high titer of anti-Nipah IgG was observed.
The transfer of humoral immunity against NiV from the mother to the neonate was confirmed for the first time in this way.
Dr Syed Moinuddin Satter, assistant scientist and deputy project coordinator, Emerging Infections, Infectious Diseases Division at icddr,b, is the study's lead researcher.
He said: “To the best of our knowledge, this finding is the first to report the vertical transfer of NiV-specific immune properties. It warrants further exploration of its effectiveness in virus neutralization and its potential to protect newborns. This will also be a reference for vaccine recommendations for pregnant and young women against the Nipah virus.”
Professor Dr Tahmina Shirin, director of the Institute of Epidemiology, Disease Control and Research (IEDCR), warns people against consuming raw date palm sap.
She said: “Recently, we are observing a profound interest among people to consume raw date palm sap and also involve in promoting this culture through social media. People indulge in it without knowing the havoc it can create. Even if someone says they have taken precautions while collecting raw date palm sap, we urge everyone not to drink it because it is still unsafe.”
Dr Tahmeed Ahmed, executive director at icddr,b, appreciated the collaborative efforts and said: “The icddr,b in partnership with the Government of Bangladesh, has been running the world's longest Nipah virus surveillance to detect Nipah virus outbreaks, understanding the disease transmission, and finding new knowledge and insights that can help develop therapeutics and vaccines against this deadly infection. The effort has been rewarding, and I hope we will soon have effective preventive measures and treatments, and be able to save lives.”
The NiV is a zoonotic virus (it is transmitted from animals to humans) and can also be transmitted through foods contaminated by animals or directly between people. Fruit bats from the genus Pteropus are its natural reservoir, and NiV is one of the present time's fatal emerging pathogens.
In Bangladesh, the virus was first reported in 2001, and since then, the NiV has become endemic to this densely populated country, with confirmed cases reported almost every year. Until January 2023, a total of 331 cases of NiV infection have been reported, and 236 patients died.