The Effectiveness of Online Counseling Methods to Improve the Knowledge of Covid 19 Vaccination in High School Students Maher Syahbani Putra Perwira a , Fatih Nugraha Abdillah a , Nabil Fauzi Barmen a , Maftuchah Rochmanti b* a Medical Study Program, Faculty of Medicine, University of Airlangga 60132, Surabaya, Indonesia b Department of Anatomy, Histology, and Pharmacology, Faculty of Medicine, University of Airlangga 60132, Surabaya, Indonesia * Corresponding Author: maftuchah-r@fk.unair.ac.id Abstract The COVID-19 pandemic, which started in Wuhan, China, has been moving around the world since late 2019. In Indonesia, the first case of a Covid-19 patient was identified on 2 March, 2020, in Depok. For now (30 July, 2021), confirmed cases in Indonesia had reached 3,372,374 cases, and 92,311 of them died. Therefore, preventive measures are needed so that the chain of Covid-19 spread in Indonesia is broken, one of which is vaccination. For now, Indonesia is in the process of accelerating vaccination coverage. It has been given to people in the 12-17 year age group, the majority of which are in high school (SMA). Based on SDGs point 4, namely quality education, especially in the field of basic education. Educational steps were taken for the community, especially high school students in several schools in Indonesia, by making online counseling activities and seeing an increase in students' understanding of knowledge related to Covid-19 vaccination. Before the counseling begins, participants will be given a questionnaire in the form of a pre-test to determine the knowledge of high school students before the counseling. After the counseling is carried out, the counseling participants will also be given a post-test to see if there is an increase in the knowledge of high school students regarding the Covid-19 vaccination. In this study, there were 157 respondents who filled out the pre-test and post-test. The results of this study showed that there was an increase in students understanding of Covid-19 vaccination after online counselling. Keywords: Basic education, Counseling, High school student, Vaccination, COVID-19 Pandemic, SDGs 1. Introduction The COVID-19 pandemic that started in Wuhan, China, has spread around the world since late 2019. COVID-19 has infected individuals of all ages and people of all economic strata. However, people who have a high risk of severe or fatal disease are older people and people with co-morbidities, such as diabetes, cancer, and other chronic diseases. In Indonesia, the first case of a COVID-19 patient was identified on 2 March 2020 in Depok (Nugraha et al., 2020). For now (30 July 2021), confirmed cases in Indonesia had reached 3,372,374 cases, and 92,311 of them have died (Kementrian Komunikasi dan Informatika, 2021)Although the number of recovered cases in Indonesia is not small, reaching 2,730,720 cases. It does not mean that all recovered patients do not have side effects such as fatigue, shortness of breath, joint pain, chest pain, headache, muscle weakness, neurological symptoms, and mental health disorders. Therefore, recovered patients still need treatment, mostly related to rehabilitation (Nugraha et al., 2020). Therefore, preventive measures are needed so that the spread of COVID-19 in Indonesia is broken, one of which is vaccination. Vaccination is the administration of vaccines (antigens) that can stimulate the formation of immunity (antibodies) of the immune system (immune) in the human body (Angel A. Justiz Vaillant; Marc J. Grella., 2021). Vaccination as a primary prevention effort is very good in preventing diseases that can be prevented by vaccination. Vaccination with the correct procedure is expected to provide optimal immunity, safe injection, and minimal Adverse Event Following Immunization (AEFI). The immune system against a disease can form naturally when a person is infected with a virus or germ that causes it (Janeway CA Jr, Travers P, Walport M, 276 www.ijrp.org IJRP 2022, 93(1), 276-283; doi:.10.47119/IJRP100931120222797