The New Coronavirus vaccine includes inactivated vaccine, adenovirus vector vaccine and recombinant New Coronavirus vaccine, which require 2, 1 and 3 doses respectively. For those who have received inactivated vaccine and recombinant neo-coronavirus vaccine, it is not recommended to skip the second dose, but to complete the second or even the third dose according to the procedure. If some people do not receive the required vaccination, the vaccine effect may be affected to some extent, such as a decrease in the defensive effect of the vaccine or even a shortening of the maintenance of the effect. Usually, vaccines that require multiple injections are able to produce antibodies in the body for a short period of time after the first dose, but the titer is insufficient to produce better protection and the duration is relatively short. Only by repeatedly stimulating the body to produce a strong immune response through multiple vaccinations can the maintenance time of antibodies be significantly extended. If some people do not complete the second or third dose of the vaccine in accordance with the prescribed time, it usually does not affect the effectiveness and safety of the vaccine and only requires timely replenishment. In principle, all doses of the new coronavirus vaccine must be administered at the original vaccination facility. If there are special circumstances, you can go to a different vaccination site, but you should make sure that you receive the same brand of vaccine to avoid adverse reactions. After receiving the new crown vaccine, some people may experience pain, redness, swelling or itching at the injection site, and transient fever, etc. Sclerosis and severe fever at the vaccination site may also occur, but it is rare for people to have symptoms such as local sterile septicemia and anaphylactic shock. At this time, the vaccinated person should take sufficient rest and eat lightly, and the uncomfortable symptoms will usually disappear gradually. If the symptoms worsen or persist, it is necessary to go to the hospital to avoid adverse consequences.