A study in the journal Science presents compelling new evidence that neurons in the brain’s memory centre, the hippocampus, continue to form well into late adulthood. The research from Karolinska Institutet in Sweden provides answers to a fundamental and long-debated question about the human brain’s adaptability.

In a Policy Forum, Erin Sorrell and colleagues – a coalition of virologists, veterinarians, and health security experts – argue that the recent proposal to permit the uncontrolled spread of highly pathogenic avian influence (HPAI) among U.S. poultry to identify birds that survive infection is dangerous and unethical. “Allowing a highly lethal, rapidly evolving, and contagious virus to run a natural course of infection in poultry would lead to unnecessary suffering of poultry and put other susceptible animals on and near affected farms at risk,” write Sorrell et al. “It would prolong exposure for farmworkers, which could increase viral adaptation and transmission risks for poultry, other peridomestic animals, and humans.” Since January 2022, over 173 million birds in the U.S. have been infected with highly HPAI. However, despite the risks, key high-ranking federal officials, including Health and Human Services Secretary Robert Kennedy Jr. and USDA Secretary Brooke Rollins, have suggested allowing HPAI to spread unchecked in poultry flocks to identify and preserve naturally resistant birds.

Here, Sorrell et al. critically evaluate the implications of the proposed strategy. According to the authors, allowing the virus to circulate freely in poultry flocks increases the risk of viral adaptation, which could create long-term reservoirs of infection that raises the risk of a future pandemic with serious public health consequences. The proposal may also have serious economic and food security implications. Poultry and eggs are vital, affordable sources of protein for Americans, and widespread infection would reduce production, increase prices, and disrupt access. Moreover, it could cost billions in animal losses and destabilize trade via global policies restricting the imports of U.S. poultry products. Rural communities would suffer disproportionately, facing economic ripple effects across farms, feed suppliers, processors, and transport networks. Instead of pursuing a high-risk "let-it-spread" strategy, Sorrell et al. suggest that public health and agricultural agencies need to reinforce surveillance, improve outbreak response, and adopt new science-based tools to reduce spillover risks and protect both public and ecological health. “The US is not prepared for uncontrolled spread of H5 in avian species – let alone in mammalian or human hosts,” write the authors. “If this policy is enacted, it will need to be rolled back in favor of collaborative, on-the-ground, and real-time implementation science.”

Trinity College Dublin now has Ireland’s first and only BioBrillouin microscope, which will enable researchers to make giant strides in the fields of inflammation, cancer, developmental biology and biomedical materials, among others. Cellular and tissue mechanics are potent regulators of disease, dysfunction and regeneration, and understanding them is thus a major focus of biomedical researchers. But existing methods are invasive and limited in the information that they can provide.