A high proportion of Ebola survivors recovered in antibody levels nearly a year after recovery, a new study from Liverpool University found.
Published today in Nature, the finding discovers that latent virus reservoirs may exist long after symptoms have been facilitated and has an impact on screening programs and vaccination strategies.
When a person is infected with the Ebola virus, their body makes antibodies to fight the disease. Antibody concentrations overflow and then slowly decay over time, providing the body with some immune defense over infection. However, little is known about antibody response over long periods of time.
Researchers from the University’s Institute of Disease, Medicine and Epidemiology monitored antibodies in a cohort of Ebola virus survivors from the 2014-2016 Sierra Leone uprising for up to 500 days after recovering from their disease. As expected, antibody levels fell slowly after the recovery phase, but then increased abruptly once again about 200 days later, only to decline thereafter. This particular pattern was observed in more than half of the participants with long-term data.
Although the Ebola virus was not visible in the plasma of participants given around the time of asymptomatic antibody recovery, the study shows that the Ebola virus may continue to enter the body of many patients recovered for a long time. ‘Hiding’ within sites of immune benefit, such as the eyes, the central nervous system or testes, the virus may begin to reproduce spontaneously, stimulating a renewed antibody response.
With this in mind, the researchers suggest that long-term follow-up of survivors is needed, and that repeated vaccination with vaccines should be considered to stimulate and maintain immune responses. in survivors.
The work was led by Dr Georgios Pollakis, Professor Bill Paxton and Professor Calum Semple at the University of Liverpool and Dr Janet Scott, now at the MRC-University of Glasgow Virus Research Center.
Research colleagues included experts from Public Health England, the National Safe Blood Service and the 34-Military Hospital, in Freetown, Sierra Leone.
The author and director of the corresponding study Dr Georgios Pollakis, Senior Lecturer at the University of Liverpool, said: “We found that many survivors have experienced a resurgence in antibodies, which cannot be explained by re disease or immunization, and indicates the need for ongoing monitoring of these patients. “
The Principal Investigator, Professor William Paxton, Professor of Virology at Liverpool University, said: “Viruses elicit a lot of surprises, but this high frequency of antibody reactivation was not something that was we expect to find out, and it shows that Ebola survivors should be vaccinated. considered to maintain immunity and to suppress other viral activity. In addition, the decisions will help us to better understand the immune system. “
Evidence of Ebola virus antigen driving an immune response hundreds of days after recovery from Ebola virus infection offers a possible way to drive Ebola Post Syndrome. The clinical science community should now step up efforts to better understand, treat and support Ebola survivors. “
Dr Janet Scott, Experimental Clinical Director, Clinical Lecturer, Infectious Diseases, Center for Virus Research, MRC-University of Glasgow
Superintendent Professor Malcolm Semple, Professor of Outbreak Medicine at the University of Liverpool, said: “This phenomenon seems to have occurred in all the surviving populations. from the Ebola virus in recent years to identify even more problems for those who have survived Ebola infection, rather than a better understanding of their problems.It is very important to emphasize that incidents have not occurred. sent an Ebola virus in this group. “
The Liverpool team is now using a similar screening method to monitor antibodies in COVID-19 survivors.
Source:
Magazine Reference:
Taken, C., et al. (2021) Ebola virus antibody depletion – stimulation in high proportions of survivors. Nature. doi.org/10.1038/s41586-020-03146-y.