[ad_1]
Immunity to the deadly Ebola virus could last for years after infection, the world’s longest survivor study by British and Guinean scientists has concluded in findings that could have implications for Covid immunity research.
The findings are the result of the world’s largest and most comprehensive study of survivors of the devastating West Africa outbreak between 2013 and 2016. They could help understand the body’s immune response to Covid and other zoonotic diseases.
A recent study suggested that antibodies to Covid can only last two months, leading to speculation that immunity to the virus may not be long-lasting and those who have recovered would be at risk of reinfection.
The team of scientists in Guinea found that some Ebola survivors showed no antibodies three months after infection, although they would have to mount a strong response to fight such a deadly virus.
But they did have the ability to fight possible reinfection with backup “killer” T cells, a type of white blood cell that triggers the immune response, and B cells that memorize the specific battle plan for a pathogen and rapidly secrete antibodies when reactivated. based on findings published in the Lancet Infectious Diseases.
Current post-Covid tests are for antibodies only and do not measure T or B cells.
“The fact that antibodies cannot be detected does not necessarily mean that someone has not acquired immunity to their infection,” said the report’s lead author, Miles Carroll, a professor at the University of Oxford and deputy director of the National Infection Service in Public Health. . England at Porton Down, Wiltshire.
The study is the largest of its kind in the world, allowing scientists to “uniquely assess both neutralizing antibody and T-cell responses” by taking blood samples over three years from 117 survivors, 66 contacts, and 23 negative control subjects in Guinea.
Their study reveals that 95% of the survivors had both antibodies and a T-cell response to the virus and there was no “significant reduction” in antibodies or T-cells more than three years after infection.
These results suggest that naturally acquired immunity is 10 times greater than that provided by the new Ebola vaccine, which was used successfully in the most recent 2018-19 outbreak in Africa.
“This finding provides compelling evidence for long-term protection against re-infection with the Ebola virus,” the study says.
It also suggests that scientists should consider the entire pathogen when designing new vaccines and not just the components that decorate the surface of the virus.
What surprised the scientists was the finding that nine of the 66 close contacts, usually mothers, of those infected with Ebola had both antibodies and T cells to the virus with no verifiable reports of symptoms.
“From this data, we would suggest that more people were actually infected with the virus than official reports suggest,” the document said. This could have implications for understanding herd immunity to other viruses, a concept now in the spotlight due to Covid.
Research also supports the existence of transmission of the virus from people without symptoms after a woman was able to transmit the Ebola virus to her child through breast milk, with fatal consequences.
Neither of the boy’s parents reported any Ebola symptoms and the blood samples were virus-free.
However, semen and breast milk were positive and it was concluded that breast milk was the most likely route of transmission.
