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Tanzania’s northwestern Kagera region serves as a transit hub to neighbouring countries. Image credit: Shutterstock/ Aleksandrkozak. Eight people have likely died from an outbreak of Marburg virus disease (MVD) in a northwestern region of Tanzania, according to the World Health Organization (WHO). The suspected outbreak has occurred in the Kagera region – the area where the first known MVD cases were diagnosed in March 2023. On 10 January 2025, the WHO received reports that five people had died from suspected MVD cases. A day later, this had risen to eight deaths from nine suspected cases, conferring an 89% case fatality ratio. The organisation then issued a disease outbreak alert on 14 January. The WHO said samples from two patients are currently being analysed to confirm MVD infection. The suspected cases, which also include healthcare workers, presented with symptoms such as headaches, fever, and vomiting blood. External haemorrhage—bleeding from orifices —was seen in the later stages of the disease. The organisation said the regional risk of this suspected outbreak is high due to Kagera’s transit hub role. The region serves as a place for significant cross-border movement to countries such as Rwanda, Uganda, Burundi and the Democratic Republic of the Congo, meaning there is a potential for MVD to spread to neighbouring countries. The national risk is also assessed as high by the agency due to the delayed detection and isolation of cases. The WHO has currently placed the global risk as low, stating that there has so far been no confirmed international spread. The agency did, however, allude to Kagera’s airport that connects to Tanzania’s largest city Dar es Salaam, where international air travel is possible. WHO Director-General Dr Tedros Adhanom Ghebreyesus said in a statement: “We would expect further cases in coming days as disease surveillance improves. WHO has offered its full assistance to the government of Tanzania, and affected communities. “We recommend neighbouring countries be on alert and prepared to manage potential cases. We do not recommend travel or trade restrictions with Tanzania at this time.” MVD is not easily transmissible, being spread through direct contact with bodily fluids. The virus can be difficult to distinguish from other infectious diseases such as malaria and other haemorrhagic fevers, with infection confirmed by diagnostic lab analysis. A species of fruit bat is considered to be the natural host of the virus, which can spread to humans working in mines or caves, but the WHO said the source of the current outbreak in Tanzania is unknown. Vaccine development Whilst there are no approved vaccines or antiviral treatments for MVD, a range of candidates are in development. The WHO has prioritised four vaccine candidates, all viral-vectored based, to combat future outbreaks. The first to enter clinical trials was cAd3-Marburg developed by the Vaccine Research Centre at the National Institute of Allergy and Infectious Diseases (NIAID). A Phase II trial (NCT05817422) was launched in October 2023 following a successful Phase I trial (NCT03475056), which showed the vaccine conferred a robust antibody response in 95% of participants. The UK’s University of Oxford has also developed a vaccine called ChAdOx1 Marburg, which entered clinical trials in July 2024. In the US, the US Food and Drug Administration awarded orphan drug designation to a vaccine being developed by Soligenix in April 2024 after positive preclinical data.

Three different HIV antibodies each independently protected monkeys from acquiring simian-HIV (SHIV) in a placebo-controlled proof-of-concept study intended to inform development of a preventive HIV vaccine for people. The antibodies -- a human broadly neutralizing antibody and two antibodies isolated from previously vaccinated monkeys -- target the fusion peptide, a site on an HIV surface protein that helps the virus fuse with and enter cells. Three different HIV antibodies each independently protected monkeys from acquiring simian-HIV (SHIV) in a placebo-controlled proof-of-concept study intended to inform development of a preventive HIV vaccine for people. The antibodies -- a human broadly neutralizing antibody and two antibodies isolated from previously vaccinated monkeys -- target the fusion peptide, a site on an HIV surface protein that helps the virus fuse with and enter cells. The study, published in Science Translational Medicine, was led by the Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Antibodies that target the fusion peptide can neutralize diverse strains of HIV in vitro, that is, in a test tube or culture dish outside of a living organism. The NIAID VRC isolated a fusion peptide-directed human antibody, called VRC34.01, from a person living with HIV who donated blood samples for research. They also isolated two antibodies from rhesus macaques -- a species of monkey with immune systems like humans' -- who previously had received a vaccine regimen designed to generate fusion peptide-directed antibodies. Demonstrating that these antibodies protect animals would validate the fusion peptide as a target for human vaccine design. SHIV challenge -- administering an infective dose of SHIV -- to rhesus macaques is a widely used animal model for assessing the performance of HIV antibodies and vaccines. In this study, rhesus macaques in each of four groups received a single intravenous infusion of one type of antibody -- a 2.5 or 10 mg/kg of bodyweight dose of VRC34.01, or one of the two vaccine-elicited rhesus macaque antibodies -- and other monkeys received a placebo infusion. To determine the protective effect of the antibodies, each monkey was challenged five days after infusion with a strain of SHIV known to be sensitive to fusion peptide-directed antibodies. All monkeys that received a placebo infusion acquired SHIV following the challenge. Among monkeys that received VRC34.01 infusions, none receiving the 10 mg/kg dose and 25% of those receiving the 2.5 mg/kg dose acquired SHIV. Of those that received the vaccine-elicited rhesus macaque antibodies, no monkeys receiving the antibody called DFPH-a.15 acquired SHIV, and 25% of those receiving the antibody called DF1W-a.01 acquired SHIV. Over time, the concentration of antibodies in the blood of animals that received DFPH-a.15 declined. Those animals were re-challenged 30 days later to see if the lower concentration of antibodies had a decreased protective effect, and half of them acquired SHIV. The three antibodies studied each provided statistically significant protection from SHIV, and the effect was dose dependent, that is, highest in monkeys with greater antibody concentrations in their blood. According to the authors, these findings represent the proof-of-concept that fusion peptide-directed antibodies can provide protection against SHIV and help determine the concentration of antibodies a vaccine would need to generate to be protective. They suggest that their findings on vaccine-elicited antibodies in some animals support further work to design preventive HIV vaccine concepts targeting the fusion peptide. They conclude that an effective HIV vaccine targeting the HIV fusion peptide likely will need to expand upon the concepts used in this study, by generating multiple varieties of fusion peptide-directed antibodies. This would increase the likelihood that the vaccine could maintain a preventive effect across the vastly diverse HIV variants in circulation.

The US National Institutes of Health (NIH) on Wednesday announced that Jeanne Marrazzo has been selected to run the National Institute of Allergy and Infectious Diseases (NIAID). The incoming director, currently head of the infectious diseases division at the University of Alabama, takes up her new role in the fall and succeeds Anthony Fauci, who led the NIH unit for 38 years before stepping down last December.With an annual budget of $6.3 billion, NIAID is the second largest of the NIH's 27 institutes and centres, after the National Cancer Institute. Acting NIH director Lawrence Tabak stated that Marrazzo "brings a wealth of leadership experience from leading international clinical trials and translational research, managing a complex organisational budget that includes research funding and mentoring trainees in all stages of professional development."Her scientific work has focused on the human microbiome, specifically as it relates to female reproductive tract infections and hormonal contraception, as well as the prevention of HIV infection using biomedical interventions, including PrEP and microbicides, and the pathogenesis and management of bacterial vaginosis, sexually transmitted diseases in HIV-infected patients and management of antibiotic resistance in gonorrhoea.NIAID supports research at universities and research organisations around the US and across the unit's 21 laboratories, including the Vaccine Research Center where Ted Pierson was recently appointed director. It is also mandated to respond to emerging and re-emerging public health threats in the US and abroad. Hugh Auchincloss has been acting director of NIAID since Fauci's departure at the end of last year. The NIH can install Marrazzo in the post without a presidential appointment or confirmation by the US Senate.Meanwhile, the Biden administration has not been able to secure a permanent appointment to run the broader NIH agency after long-time director Francis Collins stepped down at the end of 2021. Monica Bertagnolli was nominated in May, but Senator Bernie Sanders has said he will not hold a hearing on any health nominee until he sees a "robust" plan from the White House about lowering drug prices.