EFFICACY & VACCINE EFFECTIVENESS

Two measures determine how well an influenza vaccine works:

Vaccine efficacy1

Percent reduction in disease incidence in a vaccinated group compared with an unvaccinated or comparative vaccine group under optimal conditions

Usually measured in randomized controlled clinical trials

Vaccine effectiveness (VE)1

Ability of vaccine to prevent disease in real world community conditions1

Usually done with little control of who gets vaccinated, setting, and reason for vaccination. These are considered observational studies.1 For methodological reasons, effectiveness estimates are expected to be lower than efficacy estimates2


FLUMIST QUADRIVALENT efficacy and vaccine effectiveness

FLUMIST QUADRIVALENT efficacy

The effectiveness of FLUMIST QUADRIVALENT is based on data demonstrating3

  • Clinical efficacy of trivalent FluMist® (Influenza Vaccine Live, Intranasal) in children and the efficacy of trivalent FluMist in adults
  • A comparison of post-vaccination geometric mean titers (GMTs) of hemagglutination inhibition (HI) antibodies between individuals receiving trivalent FluMist and FLUMIST QUADRIVALENT
  • Clinical experience with trivalent FluMist is relevant to FLUMIST QUADRIVALENT because both vaccines are manufactured using the same process and have overlapping composition

FLUMIST QUADRIVALENT vaccine effectiveness

Public Health England (PHE) 2017/2018 End of Influenza Season Vaccine Effectiveness (VE) Data4*

PHE exists to protect and improve health and well-being and reduce health inequalities within the United Kingdom (UK)5

  • LAIV4 containing the A/Slovenia H1N1 strain was used in the UK for the 2017/2018 season6
  • Adjusted H1N1 VE estimate for LAIV4 in children aged 2-17 years old was 90.3% against A/H1N1pdm094
Adjusted influenza VE estimates for LAIV against medically-attended, laboratory-confirmed influenza by influenza type, UK, 2017/20184,*
Group
2-17 years old
A/H1N1pdm09 Adjusted VE

(95% Cl)

90.3

(16.4, 98.9)

B Adjusted VE

(95% Cl)

60.8

(8.3, 83.3)

A/H3N2 Adjusted VE

(95% Cl)

-75.5

(-283.6, 21.0)

All Adjusted VE

(95% Cl)

26.9

(-32.6, 59.7)

Adjusted influenza VE estimates for LAIV against medically-attended, laboratory-confirmed influenza by influenza type, UK, 2017/20184,*
Group
A/H1N1pdm09 adjusted VE (95% Cl)
B adjusted VE

(95% Cl)

A/H3N2 adjusted VE

(95% Cl)

All adjusted VE

(95% Cl)

2-17 years old
90.3

(16.4, 98.9)

60.8

(8.2, 83.3)

-75.5

(-289.6, 21.0)

26.9

(-32.6, 59.7)

*Adjusted for age group, risk group, sex, month, pilot area, and surveillance scheme. Influenza VE was measured from October 2017 to mid-April 2018 using a test-negative case control design across 5 primary care influenza sentinel swabbing schemes in England (two schemes), Scotland, Wales, and Northern Ireland.4

Most prevalent strain circulating in the UK during the 2017/2018 influenza season.7

CI=Confidence Interval.

  • No significant effectiveness against circulating A/H3N2 strains was demonstrated in the UK by any vaccine formulation or for any age group during the 2017/2018 season4
    • 16.4 (95% CI: -59.3, 14.9) adjusted VE against A/H3N2 (all age groups, any vaccine formulation)
  • There is no United States vaccine effectiveness data since the 2017/2018 season for LAIV4

IMPORTANT SAFETY INFORMATION


  • FLUMIST QUADRIVALENT is contraindicated in persons who have had a severe allergic reaction (eg, anaphylaxis) to any vaccine component, including egg protein, or after a previous dose of any influenza vaccine, and in children and adolescents receiving concomitant aspirin or aspirin-containing therapy
  • In clinical trials, the risks of hospitalization and wheezing were increased in children <24 months of age who received trivalent FluMist
  • Children <5 years of age with recurrent wheezing and persons of any age with asthma may be at increased risk of wheezing following FLUMIST QUADRIVALENT administration. FLUMIST QUADRIVALENT has not been studied in persons with severe asthma or active wheezing
  • If Guillain-Barré syndrome has occurred within 6 weeks of any prior influenza vaccination, the decision to give FLUMIST QUADRIVALENT should be based on careful consideration of the potential benefits and risks
  • FLUMIST QUADRIVALENT has not been studied in immunocompromised persons
  • The safety of FLUMIST QUADRIVALENT in individuals with underlying medical conditions predisposing them to wild-type influenza infection complications has not been established
  • Appropriate medical treatment and supervision must be available to manage possible anaphylactic reactions following administration of the vaccine
  • FLUMIST QUADRIVALENT may not protect all individuals receiving the vaccine
  • The most common solicited adverse reactions (occurring ≥10% in vaccine recipients and at least 5% greater than in placebo) reported were runny nose or nasal congestion in persons 2-49 years, fever >100°F in children 2-6 years, and sore throat in adults 18-49 years. Among children 2-17 years who received FLUMIST QUADRIVALENT, 32% reported runny nose or nasal congestion and 7% reported fever >100°F. Among adults 18-49 years who received FLUMIST QUADRIVALENT, 44% reported runny nose or nasal congestion and 19% reported sore throat

FLUMIST QUADRIVALENT is a vaccine indicated for active immunization of persons 2-49 years of age for the prevention of influenza disease caused by influenza A subtype viruses and type B viruses contained in the vaccine. FLUMIST QUADRIVALENT is for intranasal administration only.

Please see full Prescribing Information for FLUMIST QUADRIVALENT, including Patient Information.

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