Can the influenza (flu) vaccine and pneumococcal vaccine be administered on the same day?

Can Flu and Pneumococcal Vaccines Be Given on the Same Day?

Yes, influenza and pneumococcal vaccines can and should be administered on the same day when both are indicated. 1, 2

Primary Recommendation

The CDC/ACIP explicitly recommends simultaneous administration of pneumococcal polysaccharide vaccine and inactivated influenza vaccine for all persons for whom both vaccines are indicated, as this approach elicits satisfactory antibody responses without increasing the incidence or severity of adverse reactions. 1, 2

Administration Guidelines

When giving both vaccines on the same day:

• Administer at separate anatomic sites (different injection locations, preferably different limbs) 1, 2
• Never mix vaccines in the same syringe unless specifically FDA-approved for mixing 2
• If using high-dose or adjuvanted influenza vaccines (HD-IIV3, aIIV3), inject in different limbs when possible to minimize local reactions 1

Evidence Supporting Same-Day Administration

Immunogenicity

• Both inactivated influenza vaccines (IIV) and recombinant influenza vaccines (RIV4) can be administered concomitantly with pneumococcal vaccines without compromising immune responses 1, 2
• One study in adults ≥65 years showed slightly lower seroprotection to one influenza B antigen at 4-6 weeks when IIV4 and PPSV23 were given together, but no significant difference at 6 months 1
• Research in elderly populations demonstrated that simultaneous administration maintained antibody responses comparable to separate administration 3, 4

Safety Profile

• Large-scale studies show mild and acceptable adverse reactions with co-administration 3, 4
• In a Finnish study of 9,336 elderly persons, local reactions increased from 284 per 1,000 (flu alone) to 441 per 1,000 (both vaccines), but reactions were mild and decreased with advancing age 3
• Fever rates increased minimally (10 vs 24 per 1,000 vaccinations) with co-administration 3
• No serious adverse events have been documented with simultaneous administration 3, 4

Special Considerations

Live Attenuated Influenza Vaccine (LAIV)

• LAIV can be administered simultaneously with pneumococcal vaccines 1
• If not given simultaneously with other live vaccines, wait at least 4 weeks before administering another live vaccine 1
• This 4-week rule does NOT apply to inactivated vaccines like pneumococcal vaccines 1

Pediatric Populations

• Co-administration of IIV with PCV13 in children 6-23 months increases fever risk on days 0-1 post-vaccination and slightly increases febrile seizure risk 1
• Despite these concerns, no changes to recommendations were made—benefits outweigh risks, and febrile seizures have good prognosis 1

Adults Previously Vaccinated with PPSV23

• Adults ≥50 years previously immunized with PPSV23 can receive PCV13 and QIV simultaneously with noninferior immune responses, though pneumococcal responses may be slightly lower with co-administration 5

Common Pitfalls to Avoid

• Do not delay vaccination to separate the doses—simultaneous administration increases completion rates and provides timely protection 1, 2
• Do not assume increased reactions are dangerous—mild local reactions and low-grade fever are acceptable trade-offs for timely immunization 3, 4
• Do not use the same injection site—always use separate anatomic locations 1, 2
• Do not withhold vaccines in patients with minor illnesses—mild illness with or without fever is not a contraindication 2

Clinical Algorithm

1. Verify both vaccines are indicated for the patient based on age, risk factors, and vaccination history
2. Prepare both vaccines for administration at the same visit
3. Select separate anatomic sites (different arms preferred, especially if using adjuvanted flu vaccine)
4. Administer both vaccines simultaneously
5. Observe for 15 minutes post-vaccination as standard practice
6. Counsel patients that mild local reactions and fever are more common but not dangerous with co-administration 3