Covid infection in male mice may alter offspring anxiety
A new study from Australia’s Florey Institute of Neuroscience and Mental Health suggests that Covid-19 infection in male mice can cause changes in their sperm that influence the behavior and brain development of their future offspring. The findings, published in Nature Communications on October 11, point to possible long-lasting effects of the pandemic across generations, though researchers caution that results in humans remain to be confirmed.
How the study was conducted
Researchers infected male mice with the virus that causes Covid, then mated them with uninfected females. The health and behavior of the resulting offspring were tracked and compared with offspring from uninfected fathers. Dr. Elizabeth Kleeman, the study’s first author, highlighted a clear difference: “We found that the resulting offspring showed more anxious behaviours compared to offspring from uninfected fathers.”
The team says the changes were evident across the offspring, with the effects in females appearing as notable alterations in gene activity in the hippocampus, a brain region involved in emotion regulation.
What the findings mean on a molecular level
According to the institute, the Covid infection appeared to alter RNA molecules in the fathers’ sperm. Some of these RNA changes are linked to the regulation of genes important for brain development. Co‑senior author Dr. Carolina Gubert explained that the result may be an instance of epigenetic inheritance, whereby information outside of the DNA sequence influences how genes are expressed in the next generation.
Lead researcher Dr. Anthony Hannan stated that the work is among the first to demonstrate a potential extended impact of Covid infection on the behavior and brain development of descendants. He stressed that more work is needed to determine whether similar mechanisms operate in humans.
Implications for public health and future research
The authors emphasized caution in extrapolating from mice to people. If parallel effects were observed in humans, hundreds of millions of children could be affected over time, with meaningful public health implications. The researchers underscored the need for further studies to determine whether these RNA changes in sperm are transmitted to human offspring and how they might interact with environment and life experiences.
As the pandemic’s direct toll includes millions of deaths and widespread mental health challenges, this line of inquiry adds another layer to the conversation about long-term consequences. The research also raises questions about potential intergenerational effects of other viral infections that could influence neurodevelopment and behavior.
Context and cautions
Past work has shown that stress and environmental factors can induce epigenetic changes that affect offspring. In this case, the researchers stress that while the data are compelling in mice, the translation to humans is not guaranteed. They call for replication studies and carefully designed clinical investigations to assess any analogous effects in people and to explore potential protective or mitigating strategies.
Closing thoughts
The study contributes to a growing body of literature on how paternal health and experiences may influence offspring. If future research confirms similar patterns in humans, it could influence public health messaging, fertility counseling, and our understanding of how the Covid-19 pandemic shapes health across generations. In the meantime, the findings highlight the importance of protecting not only current populations but also considering potential lasting legacies of the virus on future generations.
