The second dose of bivalent HPV is not recommended to be given in advance, but if it is given a day earlier, it will not have a significant impact on the protective effect of the vaccine.
The human papillomavirus (HPV) vaccine requires three injections, and the three injections need to be administered according to the recommended schedule. The HPV vaccines currently available on the market have a recommended vaccination schedule on their product inserts.
For the bivalent HPV vaccine, the vaccination cycle is 0-1-6 months, i.e., the second injection and the first injection need to be at least 1 month apart, and the third injection and the second injection need to be at least 5 months apart.
In general, the timing of the second injection of bivalent HPV needs to be on time in order to increase the level titer of antibodies in the body. After the first dose of HPV vaccine, protective antibodies will start to be produced in 2-3 weeks. Continuing with the second and third doses later on will lead to a higher antibody titer in the body, which will also make the preventive effect of the vaccine more lasting.
There is no need to worry too much if the vaccine has been administered one day earlier, as the titer of the antibody is usually not greatly affected.