The decision on how soon to give the second dose after receiving the new crown vaccine depends on the type of vaccine the recipient receives. Adenovirus-vectored vaccines do not require a second dose, inactivated vaccines receive a second dose 3 to 8 weeks after the first dose, and recombinant subunit vaccines receive a second dose 4 to 8 weeks after the first dose. If the recipient is vaccinated with adenovirus-vectored vaccine, one dose is usually sufficient and a second dose is not required. If the vaccine received by the recipient is an inactivated vaccine, two doses are usually required, and the second dose can be given 3 to 8 weeks after the first dose. If the vaccine is a recombinant subunit vaccine, three doses are required, and the second dose can be given 4 to 8 weeks after the first dose. It is important to note that if a recipient has an adverse reaction after the first dose, he/she should consult a medical professional to decide whether to continue with the second dose or not, and should not be vaccinated without authorization. The safety of the New Crown vaccine is extremely high. Early vaccination not only protects you, but also helps to establish a population barrier, so you should try to get vaccinated as much as possible.