First of all, we want to thank the author for the approval of our article, focusing on SARS-CoV-2 infection in infants. Our article was aimed to describe the characteristics of infants under 1 year of age (excluding newborns) with COVID-19. Clinical features, chest imaging findings, laboratory tests results, treatments and clinical outcomes were analyzed. Our replies to the questions mentioned in author’s letter are as follows.

Although Li et al. [1] reported that the prevalence of malnutrition in elderly patients with COVID-19 was high, no signs of malnutrition (wasting or stunting) were noticed in our infant cohort.

Creatine kinase-MB has been used to assess myocardial function in our clinical practice, and all infants were tested for creatine kinase-MB during hospitalization. Troponin T was done in some infants, and only one patient received echocardiography. 19.4% infants suffered myocardial damage, and an atrial septal defect was present in one case in our cohort. We have not routinely ruled out the congenital heart defects in the infants with SARS-CoV-2 infection. The infant with atrial septal defect was not included in the group of infants with myocardial damage.

Chest CT scan showed bilateral pneumonia in 61.11% of the patients, and unilateral pneumonia in 36.11%. One infant was asymptomatic of infection. In the choice of treatment, 41.67% received antibiotics treatment and the rest received only antiviral and traditional Chinese medication.

The proportion of patients with elevated procalcitonin was higher than C-reactive protein (CRP) in the infants with SARS-CoV-2 infection, but the amplitudes of procalcitonin were not obvious in most infants. We cannot judge whether procalcitonin is a better indicator of inflammation than CRP in infants with SARS-CoV-2 infection.