The coronavirus outbreak seems to be largely avoiding infants, according to a new study.

New research looking into the cases of infants admitted to Chinese hospitals with the coronavirus (COVID-19) reports that, between December 8 and February 6, only nine such cases were recorded. As of February 14th, over 63,000 cases of coronavirus infections were recorded in China, making the number of infant cases surprisingly small in comparison. As of last week, the virus tallied over 45,000 infections worldwide and led to the deaths of over 1,000 people.

Must be this old to ride

The infants in this study were 1 to 11 months old and were admitted to the hospital with fever, coughs, or other mild respiratory symptoms, the team explains. None of them suffered any subsequent complications from the virus. Given the disproportionately low number of infant infections recorded, the authors propose that they may be less susceptible to the virus or have a lower risk of being exposed. Alternatively, it could be the case that infants contract the virus just as easily as everyone else but only develop a mild case and don’t require medical supervision.

All of the infants identified had at least one infected family member and became sick after their relatives fell ill. However, another study showed that infected mothers do not pass the virus to their children before or during birth through cesarean section. Samples of amniotic fluid from these mothers, as well as throat swabs from the newborns, showed no sign of COVID-19. Umbilical cord blood and breast milk were also found to be free of the virus. However, the authors of the second study caution that all the participants were already in their third semester, so it remains possible that the virus can spread to a fetus in the earlier stages of the pregnancy. Similarly, they all gave birth by c-section, so it is unknown whether vaginal delivery also insulates the newborn from the virus.

SARS and MERS, two coronaviruses related to the current outbreak of COVID-19, also seemed to ‘avoid’ infants. They didn’t pass to the newborns during birth and few cases of infant infections were recorded in general.

The paper “Novel Coronavirus Infection in Hospitalized Infants Under 1 Year of Age in China” has been published in the journal JAMA.