Mass vaccination to rubella, waning immunity, and neurodevelopmental disorders

Abstract Maternal viral infection during pregnancy significantly increases the risk of neuropsychiatric disorders such as autism. Unlike natural immunity to infectious agents, vaccine-induced immunity can wane over time, potentially leading to secondary vaccine failure. A direct consequence of this waning immunity is that children born to vaccinated mothers might be exposed, either prenatally or postnatally, to infections that can adversely affect neurodevelopment. To preliminary explore the epidemiological basis for this possibility, we conducted a pilot ecological study analysing the historical trends of rubella vaccination — a virus known to impact foetal brain development — and autism prevalence in the US, Japan, England/UK, Sweden, and France. The data reveal a very strong correlation (Pearson’s k = 0.8) between historical vaccine coverage and autism prevalence in the US for the period 1969-1999. We also found a strong correlation (k = 0.66) between the extent of prior rubella immunisation (1991-2009) and subsequent autism rates (2000-2018). Our analysis detected a time lag ranging from one to three decades (median 24 years) between the start of rubella immunisation programmes and a doubling in autism cases in the US, England/UK, Sweden, and Japan. The odds of being diagnosed with autism occurring 20 years following the initiation these programmes in each country were higher in the US (OR = 21.2), Sweden (OR = 3.68), and UK (OR = 2.92). While this pilot ecological study does not establish causality, the data presented here should prompt further investigation into the relationship between susceptibility to rubella and other viral infections in vaccinated populations, likely due to waning immunity, and the increase in neurodevelopmental disorders observed in recent decades.