A new study has found that maternal Zika virus infections can reprogramme foetal immune development, leading to long-term consequences in children’s immunity. These changes even occur in children born without the physical characteristics associated with congenital Zika syndrome — suggesting that the 95% of babies born of Zika-infected pregnancies who did not exhibit symptoms may have been affected by the virus with long-term immunological repercussions. Only 5% of children whose mothers experienced Zika infections during pregnancy are born with physical or neurological disabilities and diagnosed with congenital Zika syndrome. The study used blood samples from newborn and two-year-old children whose mothers were infected by Zika virus during pregnancy. Immune analysis revealed highly elevated levels of inflammation, even two years after the Zika virus infection was cleared. The affected children’s immune systems also favored producing one type of T-cell over another, altering their responses to childhood vaccines. These changes left them likely vulnerable to future infections including diphtheria, tetanus and pertussis. The presence of long-term immunological alterations in children who were deemed unaffected by Zika at birth shows an entire group of pregnancy-related Zika complications that fell through the cracks.
