The goal of this clinical trial is to test the effect of telehealth service provided to pregnant women about childhood vaccines on vaccine attitudes and vaccination.

The main questions it aims to answer are:

• Does telehealth service provided to pregnant women about childhood vaccines decrease the mean scores of the vaccine attitudes scale?
• Does telehealth service provided to pregnant women about childhood vaccines increase the vaccination?

In the intervention group, researchers will send educational materials (video and e-brochures) about childhood vaccinations to the participants' mobile phones at regular intervals, answer their questions over the phone and send reminder messages before the vaccination appointment.

In the control group, there will be no information or intervention about childhood vaccines by the researchers, and standard procedure will be followed.

Researchers will compare the intervention and control groups to see if there is a difference between vaccination attitudes and vaccination rates.

Place and Time of Research; The research will be carried out at primary care clinics in Istanbul Beylikdüzü between August 2022 and March 2023.

Population and Sample of the Research; The research population will consist of individuals who were last trimester of pregnancy in primary care clinics in Istanbul Beylikdüzü. The study sample will consist of at least 156 individuals determined by power analysis. Individuals who met the inclusion criteria were randomly assigned to the experimental and control groups with a table of random numbers.

In this study, the scales will be applied as a pre-post test. It does not pose any problem that will endanger the physical and mental health of the participants. Data collection forms; introductory information form, vaccine attitudes scale, vaccine follow-up form, and follow-up chart. Data collection tools; vaccination information video, e-brochures, reminder messages, answering parent questions via instant message, smartphone.

Before starting the research, ethics committee approval was obtained from Istanbul University-Cerrahpaşa Social and Human Sciences Ethics Committee, and institutional permission was obtained from the Istanbul Provincial Health Directorate. Participants were included in the study voluntarily. Before starting the study, participants were called by phone and informed about the study, and verbal consent was obtained with the "Informed Voluntary Consent Form."

Inclusion Criteria:

• Volunteering to participate in the study
• Having the ability to understand, speak, read and write Turkish.
• The willingness of the primary care clinic staff to be cooperated to work
• Owning and using a smartphone
• Being in the last trimester of pregnancy
• Giving birth to the baby at a birth weight (≥ 2000 g) that will not affect the routine vaccination schedule

Exclusion Criteria:

• Have a miscarriage

Since pregnancy is specific to women, the study will be conducted for women.