A recent article in Open Forum Infectious Diseases examined the effectiveness of Fluad quadrivalent, which is designed to overcome immunosenescence and enhance vaccine responses in older adults.

Industry researchers said they expanded on the CDC modeling method to estimate the number of additional influenza-related outcomes averted with adjuvanted trivalent inactivated influenza vaccine (aIIV3) versus generic quadrivalent inactivated influenza vaccine (IIV4) in adults aged 65 years and older over three influenza seasons (2017-2018 to 2019-2020) in the United States.

The study team developed a static compartmental model based on an existing CDC model with two previously recommended calculation methods that increased the accuracy of the model in providing estimates of burden averted.

Model inputs included vaccine effectiveness, vaccine coverage, population counts, and disease burden estimates. Additional burden-averted measures were based on symptomatic cases, outpatient visits, hospitalizations, ICU admissions, and deaths.

“The model estimated that vaccination with aIIV3 versus IIV4 would avert 2.24 times as many symptomatic cases, outpatient visits, hospitalizations, ICU stays, and deaths during 2017-2018; the burden averted in 2018-2019 and 2019-2020 with aIIV3 would be 3.44 and 1.72 times that averted with IIV4, respectively,” the authors reported. “Disease burden estimates and relative vaccine effectiveness of aIIV3 had the greatest impact on model estimates.”

Looking at three influenza seasons, the model estimated that aIIV3 was more effective than IIV4 in averting influenza-related outcomes. It found that the enhanced vaccine prevented 1.72 to 3.44 times as many influenza illnesses with proportionate decreases in related healthcare use and complications.

MF59 is an oil-in-water emulsion composed of squalene, which is a naturally occurring oil found in many plant and animal cells, as well as in humans, according to the CDC. It added that MF59 has been used in flu vaccines in Europe since 1997 and in the U.S. since 2016 and has an excellent safety record.

Another recent study looked at whether the adjuvanted inactivated influenza vaccine (aIIV) or high-dose inactivated influenza vaccine (HD-IIV) provided better protection. Both are FDA-approved for adults aged older than 65 years. The study, led by Duke University School of Medicine, compared serum hemagglutination inhibition (HAI) antibody titers for the A(H3N2) and A(H1N1)pdm09 and B strains after trivalent aIIV3 and trivalent HD-IIV3 in an older adult population. The results were published in the journal Immunity and Ageing.

The researchers reported no significant differences between the vaccine groups in percent seroconversion to A(H1N1)pdm09 or B vaccine strains, in percent seropositivity for any of the strains, or postvaccination geometric mean titers (GMTs) for the A(H1N1)pdm09 strain, however.

The study noted that the GMTs for the postvaccination A(H3N2) and B strains were higher after HD-IIV than after aIIV3.

“Overall immune responses were similar after aIIV3 and HD-IIV3,” the authors advised. “For the primary outcome, the aIIV3 seroconversion rate for H3N2 did not meet noninferiority criteria compared with HD-IIV3, but the HD-IIV3 seroconversion rate was not statistically superior to the aIIV3 seroconversion rate.”

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.