Adult Immunization 2015: Our Performance Review

Influenza Vaccination: In the Spotlight

Flu Vaccine Coverage for 2013-2014: Well Below HP 2020 Targets

ACIP recommends yearly flu vaccination for everyone aged 6 months or older. Last year's seasonal coverage rates are estimated using data from the National Immunization Survey-Flu (NIS-Flu) and the Behavioral Risk Factor Surveillance System (BRFFS).^[5]

The 2013-2014 flu vaccination coverage rates of 42.2% for adults aged 18 and older and 58.9% for children aged 6 months to 17 years^[1] are higher than the previous season's, but they are still well below the HP target of 90%.^[4]

Pregnant women are especially vulnerable to flu and to flu-related complications and hospitalizations.^[17] An Internet panel survey with 1619 pregnant respondents during last year's flu season reported flu vaccination of 52.2%. Clinician recommendation plays an important role. In this survey, 65.1% of women said their clinician recommended flu vaccination. Of those whose clinician both recommended and offered flu vaccination, 70.5% were vaccinated.^[6] Remember that pregnant women should be given the inactivated flu shot, but not the nasal live attenuated influenza vaccine (LAIV).^[17]

Patients with mild (hives only) egg allergy can be given the inactivated shot, but not LAIV. The recombinant flu vaccine (abbreviated RIV3; FluBlok®) contains no egg protein whatsoever and is an option for adults of all ages with egg allergy of any severity.^[17]

Flu Vaccination Scorecard for Healthcare Professionals: Slightly Better

An opt-in Internet survey of 1882 healthcare professionals found that 75.2% of those participating had received flu vaccination during the 2013-2014 season, up from 72% during the 2012-2013 season. Vaccination coverage for physicians was the highest (92.2%). Nurses were next (90.5%). Nurse practitioners and physician assistants had slightly lower rates of 89.6%. Next were pharmacists with 85.7% coverage. Medical assistants and aides were at the lower end of the coverage spectrum at 57.7%. Flu vaccination coverage was highest among those working in hospitals and was lowest for those working in long–term-care facilities.^[7]

Flu 2014-2015: Mid-Season Checkpoint

This year's flu season so far is not turning out to be as the flu gurus predicted. Two thirds of the circulating strains are a genetically drifted and particularly virulent strain of H3N2 influenza A, not covered in this year's vaccine.^[18] Thus, it is not surprising that the mid-season flu vaccine efficacy estimate is only 23%.^[19]

As a result of this reduced protection from flu vaccination, CDC has put much effort into alerting clinicians and patients about the importance of using flu antiviral drugs this season, especially for those in high-risk groups (those aged 65 and older; children under age 5, especially those under age 2; pregnant women; and those with underlying medical conditions, including asthma, diabetes, heart disease, lung disease, and the immunocompromised).^[20,21]

Although about two thirds of strains circulating so far this flu season are different from what is covered in this year's vaccine, one third of strains are covered. CDC is still recommending flu vaccination for everyone over 6 months of age. We are only mid-way through the flu season; circulating strains could change as the season progresses. But this year, the mid-season vaccine efficacy results reinforce the need to use antiviral drugs even for patients who have been vaccinated.^[20,21] There is some good news. Strains circulating so far do not show resistance to the three currently recommended flu antiviral agents^[22] the neuraminidase inhibitors:

• Oseltamivir (Tamiflu®), available as pill or liquid. Its main adverse effect is nausea and vomiting, so it should be taken with food.^[21]

• Zanamivir (Relenza®), available as a powder that is inhaled. The powder can trigger bronchospasm, so it is not recommended for anyone with asthma or chronic obstructive pulmonary disease.^[21]

• Peramivir (Rapivab™), an intravenous infusion, recently FDA-approved for adults only.^[23] The main adverse effect is diarrhea.^[21]

Antiviral agents work best when given within the first 24-48 hours after symptoms begin. However, even giving them later in the course of illness can benefit those who are ill. CDC is also reinforcing the message that it is not necessary to have lab confirmation of flu before starting antiviral therapy.^[20,21]

Final Thoughts

This flu season is a reminder of how much we depend on vaccines to protect us and save lives, and how vulnerable we are when they are either not administered or not effective. Please use the results of the 2013 NHIS scorecard and the aforementioned Internet surveys as an incentive to improve vaccination rates among your patients.

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