COVID-19’s Legacy May Extend Beyond Infection
COVID-19 has already changed the world in countless ways, but new research suggests its impact could go even deeper—possibly influencing the mental health of future generations. A groundbreaking study from Australia’s Florey Institute has discovered that infection with the SARS-CoV-2 virus may alter male sperm in ways that affect their offspring’s brain development and behavior.
The study, published in Nature Communications in 2025, offers the first evidence that a father’s COVID-19 infection could have long-term effects on his children. While the research was conducted in mice, the findings raise important questions about the potential human consequences of this global pandemic.
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The Study: How COVID-19 Alters Sperm
Researchers at the Florey Institute infected male mice with a form of SARS-CoV-2 that mimics human COVID-19 infection. After recovering, these mice were bred with healthy females. The scientists then studied the behavior and brain activity of their offspring.
Surprisingly, the offspring of the infected males—who themselves had never been exposed to the virus—showed increased signs of anxiety-like behavior. Further genetic analysis revealed that these behavioral changes were linked to alterations in RNA molecules within the fathers’ sperm.
These RNA changes appeared to modify gene expression in the offspring’s hippocampus, a brain region critical for emotion regulation, memory, and learning. In simpler terms, the virus seemed to “reprogram” sperm at the molecular level, leading to brain changes in the next generation.
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Different Effects in Males and Females
One of the most striking findings was that the impact was stronger in female offspring than in males. Female mice born to COVID-infected fathers showed more noticeable anxiety-related behaviors, suggesting a sex-specific vulnerability.
Scientists believe that certain genetic pathways involved in emotion and stress regulation may be more sensitive in developing female brains, though more research is needed to understand why.
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What This Could Mean for Humans
Although the study was performed in animals, the implications for humans are potentially serious. If similar effects occur in people, it could mean that millions of men who had COVID-19 might pass subtle but significant changes to their children through sperm.
This process, known as epigenetic inheritance, doesn’t alter the DNA sequence itself but instead affects how genes are turned on or off. Such changes can influence brain development, stress responses, and mental health outcomes.
Experts caution that it’s too early to draw conclusions about human risk, but the study highlights a possible hidden cost of the pandemic—one that could affect generations to come.
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Scientists Urge More Research
Lead researcher Dr. Elizabeth Kleeman and her team emphasize that more human-focused studies are urgently needed. They hope to investigate whether men who recovered from COVID-19 show similar RNA changes in their sperm and if their children display any related psychological or neurological effects.
Dr. Kleeman explained that the study provides a foundation for exploring how viral infections can affect reproductive health and offspring development in general. “These findings remind us that infections can have consequences that go far beyond the individual,” she said.
Other scientists not involved in the study have praised the work but also urge caution. They note that human biology is far more complex than that of mice, and many environmental and genetic factors could influence outcomes.
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A Wake-Up Call for Public Health
If confirmed in humans, these findings could have major implications for public health, mental health planning, and reproductive guidance. It could mean that even after recovering from COVID-19, some men might carry molecular “echoes” of the virus in their sperm that subtly influence their children’s brain development.
The research also highlights the importance of studying the long-term biological effects of COVID-19, not just the immediate symptoms or long COVID cases. Understanding these effects could help prevent or manage potential risks for future generations.
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Conclusion
The Australian study sheds new light on how COVID-19 might continue to shape our world in ways we’re only beginning to understand. While more research is needed to confirm these effects in humans, it’s a reminder that the impact of the pandemic may stretch far beyond the infection itself—possibly even into the genetic legacy we pass on.
Source:
Kleeman, E. et al. (2025). Paternal SARS-CoV-2 infection alters offspring anxiety-like behaviour and hippocampal gene expression via sperm RNA changes. Nature Communications.