General Recommendations for Timing and Spacing of Routinely Recommended Vaccines

1) Simultaneous administration.This recommendation states that there are no contraindications to the simultaneous administration of any of the routinely recommended vaccines included on the current ACIP schedule. The only 2 exceptions to this rule are that PCV and PPSV should be separated by 8 weeks and PCV and MenACWY-D should be separated by 4 weeks

2) No minimum time intervals between the administration of 2 different inactivated vaccines. For example, you could give a DTaP one day and a HIB the next, or 2 weeks later. Again, the two exceptions are for doses of PCV and PPSV and PCV and MenACWY-D.

3) If 2 different live virus vaccines are not administered on the same day, they must be separated by at least 4 weeks. This would apply specifically to doses of MMR and Varicella, if not administered on the same day. 

4) If 2 different live injectable vaccines are given <28 days apart, the one given second should be repeated ≥ 28 days after the second or invalid dose. 

5) This recommendation states that vaccine doses should not be given at intervals less than the minimum intervals or earlier than the minimum age. Table 3-2 of the General Recommendations gives all the minimum intervals and ages for each dose of the recommended childhood vaccines. 

6) The 4 day grace period 

• In 2002 the ACIP instituted what is referred to as the grace period, for use in evaluating immunization records. Basically, doses given ≤4 days before the minimum age or interval may be counted as valid doses.
• The exception to this is in regard to the spacing of doses of MMR and Varicella.
• This rule should be used primarily for evaluating records, NOT for scheduling visits.
• In Georgia, this rule does not conflict with the requirements for school and day care. This is not true in some states.

7) If vaccines are administered later than the recommended schedule: 

• Do not start over. 
• Do not repeat doses. 
• Continue with the rest of the series according to recommended intervals and ages. 

8) The importance of administering vaccines by the recommended routes and sites. It does, however, state that in evaluating records, all doses given by nonstandard routes and sites may be accepted except: 

• Rabies and hepatitis B given in the gluteus. 
• Hepatitis B not given IM. 
• Continue to discard and repeat vaccines given in “divided doses”. 
• Do not mix vaccines unless they are licensed to be mixed. 

9) The use of a combination vaccine generally is preferred over separate injections of its equivalent component vaccines. Considerations should include provider assessment*, patient preference, and the potential for adverse events. 

*Provider assessment should include the number of injections, vaccine availability, likelihood of improved coverage, likelihood of patient return, and storage and cost consideration. 

10) Contraindications and precautions are circumstances that dictate when vaccines should not be administered. 

• A contraindication is a condition in the recipient that increases the risk for a serious adverse reaction. 
• A precaution is a condition in the recipient that might increase the risk for a serious adverse reaction. In some circumstances it may be necessary to weigh benefits vs. risks, as in an outbreak. 

https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/timing.pdf