Concurrent Flu Vaccination and Tamiflu Post-Exposure Prophylaxis
Yes, it is absolutely fine to receive the flu vaccine and take Tamiflu (oseltamivir) for post-exposure prophylaxis simultaneously—oseltamivir use is not a contraindication to vaccination with inactivated influenza vaccine (IIV), and prophylaxis does not interfere with antibody response to the vaccine. 1, 2
Key Compatibility Points
Oseltamivir does not impair vaccine immunogenicity: The American Academy of Pediatrics explicitly states that oseltamivir use is not a contraindication to vaccination with IIV, and prophylaxis does not interfere with antibody response to influenza vaccine. 1, 2
Both can be used together in high-risk scenarios: Guidelines specifically recommend this combination for children at high risk during the 2 weeks after influenza vaccination, before optimal immunity is achieved—this is when both vaccination and antiviral chemoprophylaxis may be considered together. 1
Clinical Scenarios Where Both Are Recommended
The American Academy of Pediatrics recommends concurrent use in these specific situations:
Recently vaccinated high-risk individuals: Any child at high risk for influenza complications who received influenza vaccine in the past 2 weeks (optimal immunity may not yet be achieved). 1
Immunocompromised patients: As a supplement to vaccination among children at high risk, including those who are immunocompromised and may not respond with sufficient protective immune responses after vaccination. 1
Vaccine-strain mismatch: For children at high risk when circulating strains of influenza virus in the community are not well matched with seasonal vaccine strains. 1
Important Caveat with Live Attenuated Vaccine
LAIV (nasal spray) requires different timing: While oseltamivir does not interfere with IIV, LAIV effectiveness will be decreased in children receiving oseltamivir, so timing considerations are needed for the live vaccine formulation. 1
Zanamivir impact on LAIV is unknown: No data are available on the impact of inhaled zanamivir on the effectiveness of LAIV. 1
Post-Exposure Prophylaxis Dosing
For adults and adolescents ≥13 years after exposure:
Standard dosing: Oseltamivir 75 mg once daily for 10 days following close contact with an infected individual. 1, 3
Timing is critical: Initiate as soon as possible after exposure, ideally within 48 hours—prophylaxis should not be initiated if more than 48 hours has elapsed since exposure. 2
Critical Clinical Pearls
Vaccination remains primary prevention: Oseltamivir prophylaxis is not a substitute for annual influenza vaccination, which remains the primary means of influenza prevention. 4, 3
Risk persists during prophylaxis: Patients should be informed that risk of influenza is lowered but not eliminated while taking medication, and susceptibility returns when medication is stopped. 1, 4
Monitor for breakthrough infection: If symptoms develop during prophylaxis, switch to treatment dosing (75 mg twice daily) and consider testing for influenza. 2