Scientists advance Ebola, HIV treatment options
Scientists have advanced treatment options for Ebola Virus Disease (EVD) and the Human Immuno-deficiency Virus (HIV).
They have developed a new medication that in one dose successfully protected nonhuman primates against a lethal infection of all strains of the deadly Ebola virus. The findings are now available in Cell Host & Microbe.
Dr. Thomas Geisbert, a world-renowned Ebola researcher at The University of Texas Medical Branch, said that previous therapeutics typically were of the “one bug, one drug” variety. But because of the unpredictable nature and variety of the Ebola virus, scientists have been seeking a way to protect against different strains of the virus.
“Our experimental drug can protect against all forms of Ebola known to harm people, suggesting that it will continue to protect people if the Ebola viruses evolve over time,” said Geisbert, who is a professor of microbiology and immunology at UTMB.
The team of scientists demonstrated that a two-antibody cocktail called MBP134 could fully protect nonhuman primates and ferrets against lethal Ebola virus infections of caused by the Bundibugyo and Sudan strain as well as the deadliest Zaire strain that caused the 2013-16 epidemic in West Africa and the current outbreak in the Democratic Republic of Congo.
“We were able to protect the nonhuman primates against all the Ebola species plaguing people at a single low dose,” said Larry Zeitlin, president of Mapp Biopharmaceutical Inc. “Further studies exploring even lower doses could open the door to treatment via auto-injectors like the kind used for allergic reactions. The ability to quickly and efficiently provide protection against all Ebola viruses in a single dose would reduce the burden on health care workers in the field during outbreaks, especially in regions that have a less-developed infrastructure.”
A new high-throughput, miniature, portable sequencing technique has been developed in recent years, for human and animal health purposes. It uses mobile laboratories to diagnose viruses such as Ebola or Zika almost instantly, in the field. Diagnosis is both quick and early, which avoids the need to transfer contaminated samples.
Mobile, instant diagnosis of plant viruses, to back up epidemiosurveillance networks
As with human virology, the fact that the technique has now been validated in a plant virology laboratory paves the way for real-time, mobile detection of chronic, seasonal or emerging plant viruses, even in isolated areas. By shortening the time that elapses between sampling and diagnosis, the technology will help epidemiosurveillance networks detect harmful organisms at an earlier stage.
Also, scientists have developed a combination of monoclonal antibodies that protected animals from all three Ebola viruses that cause human disease. The antibody ‘cocktail,’ called MBP134, is the first experimental treatment to protect monkeys against Ebola virus (formerly known as Ebola Zaire), as well as Sudan virus and Bundibugyo virus, and could lead to a broadly effective therapeutic.
Scientists from academia, industry, and government have developed a combination of monoclonal antibodies (mAbs) that protected animals from all three Ebola viruses known to cause human disease.
Their work is described in two companion studies published online in the journal Cell Host & Microbe.
The mAb “cocktail,” called MBP134, is the first experimental treatment to protect monkeys against Ebola virus (formerly known as Ebola Zaire), as well as Sudan virus and Bundibugyo virus, and could lead to a broadly effective therapeutic, according to the authors.
Over 20 Ebola virus outbreaks have occurred since the first outbreak was documented in 1976 in the Democratic Republic of Congo, or DRC (formerly called Zaire). The 2013-2016 Ebola epidemic in Western Africa — the largest outbreak to date — sickened more than 28,000 people and caused more than 11,000 deaths. An ongoing outbreak in the eastern Kivu region of DRC is already the second largest on record, according to the World Health Organization.
No Ebola virus medical countermeasures have been approved by the U.S. Food and Drug Administration. An experimental vaccine and several experimental therapeutics — including three based on mAbs — are being studied in the field. Despite their promise, all target only a single Ebola virus (Zaire) and are ineffective against the other two.
“Developing a single treatment that could potentially be used for patients suffering from all the different types of Ebola viruses is an enormous advancement in the field,” commented John M. Dye, Ph.D. of the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), one of the authors.
Citing growing evidence of the value of monoclonal antibodies for treating even the most virulent infections, Dye added, “This discovery has implications not only for the treatment of Sudan and Bundibugyo viruses, but for newly emerging Ebola viruses as well.”
The two mAbs that make up MBP134 were previously discovered by the same research team in the blood of a human survivor of the 2013-2016 outbreak in Western Africa and were shown to target key sites of vulnerability shared by Ebola viruses.
In the first study, a team led by Kartik Chandran, Ph.D., of the Albert Einstein College of Medicine (Einstein) engineered one of the mAbs to improve its activity against Sudan virus. They demonstrated that this enhanced mAb could work especially well with the second naturally occurring mAb to block infection by all three viruses and protect guinea pigs against both Ebola virus and Sudan virus. Additional modification of both mAbs to harness the power of “natural killer” immune cells enhanced MBP134’s broad protective efficacy in guinea pigs even further.
In the second study, a team led by Dr. Zachary A. Bornholdt, Ph.D., of Mapp Biopharmaceutical Inc. (MappBio) evaluated the MBP134 cocktail in large animal models that mimic Ebola virus disease in humans more closely. They found that a single low dose of MBP134 could protect monkeys against all three Ebola viruses associated with human disease, even when treatment was begun four-seven days after the animals were infected.
Meanwhile, in recent years, an overwhelming body of clinical evidence has firmly established the Human Immuno-deficiency Virus (HIV) Undetectable = Untransmittable (U=U) concept as scientifically sound, say officials from the United State National Institutes of Health (NIH). U=U means that people living with HIV who achieve and maintain an undetectable viral load—the amount of HIV in the blood—by taking and adhering to antiretroviral therapy (ART) as prescribed cannot sexually transmit the virus to others.
Writing in JAMA, officials from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) review the scientific evidence underlying U=U and discuss the implications of widespread acceptance of the message.
In the new commentary, NIAID Director Anthony S. Fauci, M.D., and colleagues summarize results from large clinical trials and cohort studies validating U=U. The landmark NIH-funded HPTN 052 clinical trial showed that no linked HIV transmissions occurred among HIV sero-different heterosexual couples when the partner living with HIV had a durably suppressed viral load. Subsequently, the PARTNER and Opposites Attract studies confirmed these findings and extended them to male-male couples.
Validation of the HIV treatment as prevention strategy and acceptance of the U=U concept as scientifically sound have numerous behavioral, social and legal implications, the NIAID officials note. U=U can help control the HIV pandemic by preventing HIV transmission, and it can reduce the stigma that many people with HIV face.
The success of U=U as an HIV prevention method depends on achieving and maintaining an undetectable viral load by taking ART daily as prescribed. Numerous factors, including lack of access to quality health care, can make ART adherence difficult. To enhance the overall success of U=U, the authors emphasize the importance of implementing programs that help patients remain in care and address the barriers to daily therapy.