Younger Swedes show shifting immunity to common herpesviruses

<p>Background: Human herpesviruses are widespread among the human population. The infections often occur unnoticed, but severe disease as well as long-term sequelae are part of the symptom spectrum. The prevalence varies among subpopulations and with time. The aim of this study was to describe the seroprevalence of Immunoglobulin G against <em>Herpes simplex 1, Herpes simplex 2</em>, Epstein-Barr virus and Cytomegalovirus in the adult Swedish population over a time period of several decades.</p><p>Methods: Serum samples (n = 892) from biobanks, originating from 30-year-old women, 50-year-old men and 50-year-old women sampled between 1975 and 2018, were analyzed for presence of anti-herpesvirus antibodies. Linear regression analysis was used to test for a correlation between birth year and seroprevalence. Multiple linear regression analysis was used to differentiate between other factors such as age and gender.</p><p>Results: Birth year correlated negatively with the prevalence of immunoglobulin G against <em>Herpes simplex 1</em> and Epstein-Barr virus (p = 0.004 and 0.033), and positively with Immunoglobulin G against Cytomegalovirus (p = 0.039). When participant categories were analyzed separately, birth year correlated negatively with the prevalence of Immunoglobulin G against <em>Herpes simplex 1</em> and <em>Herpes simplex 2</em> (p = 0.032 and 0.028) in 30-year-old women, and with the prevalence of Immunoglobulin G against Cytomegalovirus in 50-year-old men (p = 0.011).</p><p>Conclusions: The prevalence of Immunoglobulin G against <em>Herpes simplex 1, Herpes simplex 2</em> and Epstein-Barr virus decreases in later birth cohorts. This indicates a trend of declining risk of getting infected with these viruses as a child and adolescent.</p>