This review is aimed at looking at the Covid-19 vaccine, formula and comparison of mRNA (Moderna and Pfizer) and adenovirus vector (AstraZeneca) vaccines that have been circulating in terms of administration, effectiveness, safety, side effects, contraindications, and in terms of price. This review was conducted by taking some literature from a database that focuses on the Covid vaccine, the development of the Covid vaccine, the Moderna vaccine, the Pfizer vaccine, and the AstraZeneca vaccine. Three vaccines, 2 were mRNA-based vaccines (Moderna and Pfizer) and 1, namely AstraZeneca, was based on adenovirus vectors. The results obtained are from international journals with the keyword comparison of mRNA vaccine and adenovirus vector, then the results show that the comparison can be seen through the method carried out. Some vaccines have their own advantages and disadvantages. When viewed from several aspects, such as administration which has different doses. Then seen from the effectiveness of the three vaccines have a sufficient value because they are above 80%. For safety, it has passed clinical trials in humans, but there are still shortcomings in each vaccine of course. Vaccines derived from mRNA (Moderna) are the most expensive vaccines because of the highest safety.