Can a patient receive a vaccine and then have Keytruda (pembrolizumab) the next day?

Administering Capvaxive and Keytruda on Consecutive Days

Yes, a patient can receive Capvaxive (pneumococcal conjugate vaccine) one day and then receive Keytruda (pembrolizumab) the next day, as inactivated vaccines like Capvaxive do not interfere with immunotherapy and can be administered at any time before or after other medications.

Vaccine-Immunotherapy Timing Principles

Inactivated vaccines can be administered at any interval before or after immunotherapy agents like pembrolizumab. The key distinction is that Capvaxive is an inactivated (non-live) vaccine, which fundamentally changes the timing considerations 1.

• Inactivated vaccines do not interfere with immune responses to other medications or treatments 1
• There is no required waiting period between inactivated vaccines and immunotherapy agents 1
• The general principle is that inactivated vaccines may be administered concomitantly with, or at any time before or after, other treatments 2

Specific Guidance for Cancer Patients on Immunotherapy

For patients receiving immune checkpoint inhibitors like pembrolizumab, vaccines should be administered on availability without delay 1.

• Patients on immune checkpoint inhibitors can receive vaccines at any time during their treatment course 1
• The timing recommendation is "on vaccine availability" for patients receiving immunotherapy agents 1
• Unlike some other cancer treatments (such as rituximab or intensive chemotherapy), pembrolizumab does not require specific timing windows around vaccination 1

Safety Considerations

Vaccination does not increase immune-related adverse events (irAEs) from pembrolizumab and may actually be protective 3.

• A retrospective study of 162 cancer patients receiving pembrolizumab found that influenza vaccination was independently associated with fewer irAEs (odds ratio 0.4,95% CI 0.2-0.9) 3
• The vaccinated group had lower incidence of any grade irAEs (25.7% vs 40.2%) compared to non-vaccinated patients 3
• No treatment-related deaths were reported in studies combining vaccines with pembrolizumab 4, 5

Practical Administration Approach

The optimal approach is to administer Capvaxive when available, followed by pembrolizumab on its scheduled day 1.

• Each medication should be administered using proper technique at appropriate anatomic sites 6, 2
• A 15-20 minute observation period following vaccination is recommended, as syncope can occur after vaccination 6, 2
• Minor illnesses without fever are not contraindications for vaccination 6, 2

Important Caveats

The main consideration is distinguishing vaccine-related side effects from pembrolizumab-related immune adverse events 1.

• Document vaccination details (including vaccine name, date, and administration site) to enable accurate assessment of any subsequent adverse events 1
• Common vaccine-related effects (injection site reactions, fever, malaise) should be expected and distinguished from irAEs 7, 4
• If the patient develops fever or systemic symptoms, clinical judgment is needed to determine whether these are vaccine-related (typically resolving within 24-48 hours) or represent pembrolizumab-related toxicity

There is no medical reason to delay pembrolizumab after receiving Capvaxive, and doing so could unnecessarily interrupt cancer treatment.