By Ana Espino | Published on June 09, 2026 | 4 min read
Differences between women and men in their responses to
infections, autoimmune diseases, and vaccines have long been recognized. Women
generally develop stronger immune responses than men, which may provide better
protection against certain infections but also increase their susceptibility to
autoimmune diseases.
However, most scientific studies continue to examine these
differences through a relatively static lens, simply comparing males and
females. This approach overlooks a critical factor: female immunity
continuously evolves throughout life under the influence of major hormonal
transitions such as puberty, pregnancy, and menopause.
In an editorial published in Biology of Sex Differences
in 2026, American researchers propose rethinking the study of immune
differences through a life-course approach, which considers all stages
of life. Their objective is to demonstrate that age and biological transitions
are major determinants of immune function and should be systematically
integrated into both research and clinical practice.
An Immune System That Changes at Every Stage of Life
The authors draw on a wide range of existing immunological
evidence to illustrate how major biological transitions influence immune system
function.
During puberty, hormonal changes contribute to immune
maturation and coincide with the emergence of certain autoimmune diseases.
Throughout the reproductive years, women often exhibit stronger vaccine
responses but also a higher prevalence of autoimmune disorders.
Pregnancy represents a particularly unique period.
The immune system must achieve a delicate balance between tolerating the fetus
and maintaining protection against infectious agents. This adaptation can alter
susceptibility to infections as well as the course of certain autoimmune
diseases. Following childbirth, an “immune rebound” is frequently observed.
Perimenopause and menopause are associated with a
progressive decline in sex hormones, accompanied by inflammatory, metabolic,
and immunological changes. Finally, aging is characterized by
immunosenescence, including reduced vaccine effectiveness and increased
vulnerability to chronic diseases. The framework presented by the authors
clearly illustrates this gradual evolution of female immunity across the
lifespan.
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Rethinking Research to Better Understand Women’s Health
The authors emphasize that failing to account for these
biological stages currently limits our understanding of immune mechanisms. They
note, for example, that nearly 80% of patients with autoimmune diseases are
women, and that responses to infections and vaccines often vary according
to both sex and age.
They therefore advocate for studies that incorporate factors
such as hormonal status, reproductive history, pregnancy, menopause, and
environmental exposures throughout life. Such an approach would provide
data that more accurately reflect biological reality and could improve the
precision of prevention strategies, vaccination programs, and therapeutic
interventions.
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A New Way of Thinking About Immunology
This article does not present new experimental findings but
rather proposes a paradigm shift in the way immune differences between sexes
are studied. The authors argue that female immunity cannot be fully understood
through a simple male-versus-female comparison conducted at a single point in
time.
They also acknowledge that available data remain fragmented
for certain life stages, particularly pregnancy, breastfeeding, and
menopause, which have historically been underrepresented in clinical
research.
According to the authors, systematically integrating a life-course
perspective into future studies could improve our understanding of
immune-mediated diseases, help reduce certain health inequalities, and support
the development of more personalized therapeutic approaches for women.
About the author – Ana Espino
PhD in Immunology, specialized in Virology
As a scientific writer, Ana is passionate about bridging the gap between research and real-world impact. With expertise in immunology, virology, oncology, and clinical studies, she makes complex science clear and accessible. Her mission: to accelerate knowledge sharing and empower evidence-based decisions. 
