Overview: A glimpse into potential intergenerational effects
Researchers at the Florey Institute of Neuroscience and Mental Health in Melbourne report that Covid-19 infection in male mice caused changes in their sperm that correlated with increased anxiety-like behaviours in their offspring. The findings, published in Nature Communications, raise questions about whether the virus could have lasting effects beyond the individuals directly infected and into future generations.
What the study involved
The team infected male mice with the virus that causes Covid-19 and then bred them with uninfected females. The offspring were monitored for behavioural changes and examined for molecular signatures that could explain any observed differences. According to the study’s lead author, Elizabeth Kleeman, “We found that the resulting offspring showed more anxious behaviours compared to offspring from uninfected fathers.”
Key findings: Epigenetic changes in the brain
The researchers reported that all offspring of Covid-infected fathers exhibited anxiety-like behaviours. They also observed significant changes in gene activity within the hippocampus of female offspring, a brain region critical for regulating emotions. Co-senior author Carolina Gubert explained that these changes might contribute to anxiety through epigenetic inheritance and altered brain development.
Mechanisms: What’s in the sperm?
The study found that the virus altered RNA molecules in the fathers’ sperm. Some of these RNA changes are involved in regulating genes important for brain development. Lead researcher Anthony Hannan noted that while these findings illuminate a possible pathway, more work is needed to determine whether similar phenomena occur in humans and what the broader health implications might be.
Implications for humans and public health
Although the study was conducted in mice, the researchers emphasize cautious interpretation when translating to humans. If similar epigenetic changes occur in people, the pandemic could have unforeseen consequences for the mental health of subsequent generations. Dr. Hannan underscored that this possibility warrants further investigation and public health consideration, especially given the scale of Covid-19 exposure worldwide.
Context: Mental health and the pandemic’s long shadow
The Covid era has left lasting mental health impacts across populations. Younger people, in particular, faced disruptions to schooling, social development, and routine care. A 2023 Nature Human Behaviour review found that learning gaps from pandemic-era disruptions persisted across many countries, underscoring the broader psychological costs of the pandemic beyond acute infection.
Limitations and next steps
Researchers are clear that animal studies do not prove similar effects in humans. The team advocates additional research across species and eventual clinical studies to explore whether paternal Covid infection affects human offspring. If future work confirms these findings, it could influence guidelines around family planning, public health messaging, and long-term monitoring of mental health in children of fathers who had Covid-19.
Conclusion: A potential clue to long-term consequences
The Melbourne study offers a provocative signal that viral infections can leave marks beyond the individual, potentially shaping brain development and behaviour in offspring through epigenetic pathways. While far from a definitive prediction for humans, the research contributes to a growing understanding of how pandemics may echo through generations—should the results be echoed in human biology.
