In 2025, science saw its breakthroughs, which BioWorld will be covering as part of our end-of-the-year wrap-up. But the biggest science story of 2025 is not about any scientific advance. It is the politicized destruction of U.S. science, and the dismantling of a scientific ecosystem that has been the envy of the world since it emerged after Germany destroyed its own pre-eminence in the 1930s.

Advances in antiretroviral therapy (ART) now allow people living with HIV to lead normal lives with undetectable and nontransmissible levels of the virus in their blood. Yet that reality is limited to those with access to treatment. More than 40 million people worldwide live with HIV, with over a million new infections and hundreds of thousands of deaths each year, underscoring that major challenges remain.

The cardiomyositis that is a rare adverse effect of mRNA-based COVID vaccines is due to immune cell activity as a result of increased levels of the chemokines CXCL10 and interferon-γ (IFN-γ). Blocking CXCL10 and IFN-γ could prevent muscle cell damage in cell culture, and cardiomyositis in animal models. The findings, reported in the Dec. 10, 2025, issue of Science Translational Medicine, suggest a way of mitigating the risk of cardiomyositis.

Epilepsygtx Ltd. has raised a $33 million series A to fund a phase I/IIa trial of EPY-201, a gene therapy for treating drug-resistant focal epilepsy. EPY-201 uses an adeno-associated viral vector to deliver KCNA1, the gene encoding Kv1.1, a potassium ion channel that modulates neuronal excitability.

The UK Health Security Agency (UKHSA) has identified a new recombinant strain of mpox (formerly monkeypox) that contains elements of clade Ib and clade IIb of the virus, in a traveler who recently returned from Asia. In a paper describing the new strain, the researchers at UKHSA say it is not possible to determine from a single genome how long the recombinant virus has been in circulation, or whether it will have a fitness benefit over currently circulating lineages.

Australian researchers have found a drug combination that can bypass the cellular defenses in neuroblastoma that lead to relapse, and the discovery could lead to better treatment strategies for children whose cancers have stopped responding to standard chemotherapy.

The first phase of the U.K. synthetic human genome project has successfully completed, realizing key steps in chromosome synthesis. The work has demonstrated a multistep method for transfecting mouse stem cells with native human chromosomes, where they are stably maintained and can be manipulated to replace native DNA with synthetic DNA. The engineered chromosomes can then be transferred into a human cell in place of the native chromosomes.

On Dec. 2, 2025, the FDA released draft guidance that could reduce the use of nonhuman primates (NHPs) in preclinical testing of monoclonal antibodies. According to the guidance, which the FDA released for the purpose of soliciting comments, “In general, studies longer than 3 months in nonrodent species (e.g., NHPs, dogs, and mini-pigs) are not warranted to evaluate toxicities … when data from 3-month studies are supplemented with a weight-of-evidence (WoE) risk assessment.”

Australian researchers have found a drug combination that can bypass the cellular defenses in neuroblastoma that lead to relapse, and the discovery could lead to better treatment strategies for children whose cancers have stopped responding to standard chemotherapy.

2025 has been the most challenging year in the efforts to fight HIV since at least the advent of antiretroviral therapy. In a report on “Overcoming disruption, transforming the AIDS response,” released last week ahead of World AIDS Day on Dec. 1, the Joint United Nations Program on HIV/AIDS (UNAIDS) described “a global system in shock” by sharply reduced funding from the U.S. and other wealthy nations. Scientifically, for now, progress is ongoing. To mark World AIDS Day, Nature published three independent studies on HIV.