The next time your baby is scheduled to receive a vaccination, you may want to consider booking the appointment in the afternoon.

Researchers from the University of California, San Francisco, found that babies vaccinated in the afternoon – after 1:30 p.m. – have a better response to the vaccine and sleep more in the first 24 hours after the shot

Sleep is essential during this time, because it helps facilitate a healthy immune response and increases antibody production, according to experts.

“They found these babies were more likely to sleep a longer period of time if they were given their vaccine in the afternoon, as opposed to in the morning,” said Pediatrician Dr. Kim Giuliano of the Cleveland Clinic, who did not participate in the study.

The study looked at 70 infants, and researchers found that infants who received vaccines after 1:30 p.m. slept more than infants who received the shot earlier in the day. Most infants who received the shots in the afternoon had an expected increase in body temperature, but taking acetaminophen before or after the appointment was associated with small increases in sleeping.

Giuliano said she agrees more sleep is needed for these infants, but advises parents to hold off on giving them acetaminophen.

“It’s certainly worth considering if your schedule allows to potentially try to schedule your baby’s vaccines in the afternoon as opposed to the morning,” Giuliano said. “It would be a good idea though, based off of this study and some others to consider holding off on the acetaminophen, in terms of preventing fevers and let the child amount their own response.”

The study was published in the journal Pediatrics.