1. Vaccines delayed without restriction: Hepatitis B vaccine, polio vaccine, DPT vaccine, MMR vaccine, rheumatic brain vaccine, encephalitis B vaccine, varicella vaccine, chickenpox vaccine, Hepatitis A vaccine, influenza vaccine, 23-valent pneumococcal polysaccharide vaccine, and so on. 2.Vaccines that need to be vaccinated according to the vaccine instruction program: 1) 13-valent pneumococcal conjugate vaccine: different regulations around the world; 2) quadruple vaccine: no clear regulations; 3) BCG vaccine: ＜3-month-old infants can be directly replenished; 3-month-old-3-year-old children should first do tuberculin pure protein derivative (TB-PPD) test, the results are negative before the replenishment of the vaccine; ≥4-year-old children will not be replenished. 3.Will delaying vaccination affect the effect? No, it will not affect the final effect, but the time of protection may be delayed accordingly, and delayed vaccination may increase the risk of infection. 4.Do I need to start the vaccination from the beginning after the delay? Except for the oral typhoid vaccine, there is no need to restart from the first dose for the second and subsequent doses of other vaccines, no matter how long they have been delayed, as long as the remaining doses are made up. For oral typhoid vaccine (Ty21a), if it is within 3 weeks from the last dose, you only need to make up the subsequent doses; if it is more than 3 weeks from the last dose, you need to restart the whole immunization program.