Vaccination: A Key Weapon in the Occupational Health Arsenal

One of the key interventions in occupational health is vaccination, particularly to protect against influenza. Flu among healthcare personnel (HCP) can lead to lost workdays and can spread to other workers and to patients who are at significant risk of serious flu complications. Flu vaccination of HCP has been shown to reduce the risk of flu and absenteeism in vaccinated HCP and reduce the risk of respiratory illness and deaths.

While we won't know what the vaccine coverage for healthcare workers was for 2018 until next year, the Centers for Disease Control and Prevention (CDC) reported that last season, 67.6 percent of HCP received their influenza vaccination. The agency found that during the previous two seasons, flu vaccination coverage increased by 10 to 12 percentage points from early season to the end of the season.

By occupation, early-season flu vaccination coverage for 2017-2018 was highest among pharmacists (86.4 percent), physicians (82.7 percent), nurses (80.9 percent), nurse practitioners/physician assistants (79.7 percent), and other clinical personnel (75.1 percent). Flu vaccination coverage was lowest among administrative and nonclinical support staff (61.0 percent) and assistants and aides (56.2 percent). 
By work setting, early season flu vaccination coverage was highest among HCP working in hospitals (82.6 percent). Of concern, flu vaccination coverage continues to be lower among HCP working in long-term care (LTC) settings (58.5 percent) compared with those working in hospitals and ambulatory-care settings (68.7 percent).

Early-season flu vaccination coverage was higher among HCP whose employers required (88.4 percent) or recommended (65.1 percent) that they be vaccinated compared with HCP whose employer did not have a requirement or a recommendation regarding flu vaccination (29.8 percent). Among unvaccinated HCP who did not intend to get the flu vaccination during this flu season, the most common reason reported for not getting vaccinated was fear of experiencing side effects or getting sick from the vaccine (22.1 percent).

The Advisory Committee on Immunization Practices (ACIP) recommends that all HCP receive an annual flu vaccination. Interventions to promote flu vaccination among HCP each season include employers offering flu vaccination to HCP at the worksite over multiple days and shifts, free of charge, and with active promotion. Educational materials should be provided to address questions and misperceptions about flu vaccination benefits and risks.

Measurement and feedback of vaccination coverage are recommended to increase uptake of recommended vaccinations. Measures such as the requirements by the Centers for Medicare and Medicaid Services (CMS) for acute-care hospitals, ambulatory surgery centers, and outpatient dialysis facilities to report HCP influenza vaccination coverage rates for their facilities may be useful for this purpose.

To help guide best practices for healthcare worker immunization, earlier this year the Association of Occupational Health Professionals in Healthcare (AOHP) released a Position Statement on Best Practices for Healthcare Worker Immunizations. AOHP advises that healthcare employers adopt practices ensuring healthcare workers are assessed for immunization status and properly immunized against vaccine-preventable diseases.
AOHP's position statement is based on a thorough review of the recommendations of the ACIP, which comprises medical and public health experts who develop recommendations on the use of vaccines in the U.S. civilian population. These recommendations stand as public health guidance for safe use of vaccines and related biological products.

"AOHP is committed to promoting recommended immunizations for healthcare workers and the Standards for Adult Immunization Practice in healthcare organizations represented by AOHP members," explains AOHP executive president Mary Bliss, RN, COHN. "These vaccines, which protect both healthcare workers and their patients, should be offered at no charge and must comply with state and federal regulations."

Specific vaccine recommendations included in the AOHP position statement include:

• Hepatitis B

• MMR - Measles, Mumps, Rubella

• Varicella - Chicken Pox

• Tdap/Td - Tetanus, Diphtheria, Pertussis

• Influenza

• Neisseria Meningitidis - Meningococcus (Meningitis)

In many cases, AOHP recommends that healthcare workers who refuse recommended immunizations should be required to provide a declination statement and not be engaged in direct or indirect patient care. Regarding influenza, AOHP advocates that healthcare workers should be vaccinated annually and asks healthcare administrators to consider a policy that makes annual influenza vaccination mandatory (with medical exemptions) or offer alternatives to vaccination such as requiring the use of surgical masks for patient care by healthcare workers who refuse the vaccine.

Recommendations for the composition of Northern Hemisphere influenza vaccines are made by the World Health Organization (WHO), which organizes a consultation, generally in February of each year. Surveillance data are reviewed, and candidate vaccine viruses are discussed. The WHO's Vaccines and Related Biological Products Advisory Committee (VRBPAC) considers the recommendations of WHO, reviews and discusses similar data, and makes a final decision regarding vaccine virus composition for influenza vaccines licensed and marketed in the U.S.

As for the current flu season, Grohskopf, et al. (2018) summarize the 2018-19 recommendations of the ACIP regarding the use of seasonal influenza vaccines in the U.S.: "Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. A licensed, recommended, and age-appropriate vaccine should be used. Inactivated influenza vaccines (IIVs), recombinant influenza vaccine (RIV), and live attenuated influenza vaccine (LAIV) are expected to be available for the 2018–19 season. Standard-dose, unadjuvanted, inactivated influenza vaccines will be available in quadrivalent (IIV4) and trivalent (IIV3) formulations. Recombinant influenza vaccine (RIV4) and live attenuated influenza vaccine (LAIV4) will be available in quadrivalent formulations. High-dose inactivated influenza vaccine (HD-IIV3) and adjuvanted inactivated influenza vaccine (aIIV3) will be available in trivalent formulations."

Grohskopf, et al. (2018) explain the primary changes for this flu season:

• Routine annual influenza vaccination of all persons aged ≥6 months without contraindications continues to be recommended. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. Updated information and guidance in this report includes the following:

• Vaccine viruses included in the 2018-19 U.S. trivalent influenza vaccines will be an A/Michigan/45/2015 (H1N1)pdm09–like virus, an A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus, and a B/Colorado/06/2017–like virus (Victoria lineage). Quadrivalent influenza vaccines will contain these three viruses and an additional influenza B vaccine virus, a B/Phuket/3073/2013–like virus (Yamagata lineage).

• Following two seasons (2016-17 and 2017-18) during which ACIP recommended that LAIV4 not be used, ACIP voted in February 2018 to recommend that for the 2018-19 season, vaccination providers may choose to administer any licensed, age-appropriate influenza vaccine (IIV, RIV4, or LAIV4). LAIV4 is an option for those for whom it is appropriate.

• Persons with a history of egg allergy of any severity may receive any licensed, recommended, and age-appropriate influenza vaccine (IIV, RIV4, or LAIV4). IIV and RIV4 have been previously recommended. Use of LAIV4 for persons with egg allergy was approved by ACIP in February 2016. Additional recommendations concerning vaccination of egg-allergic persons are discussed.

References:
Association of Occupational Health Professionals in Healthcare (AOHP). Position Statement on Best Practices for Healthcare Worker Immunizations. May 2018.
Centers for Disease Control and Prevention (CDC). Health Care Personnel and Flu Vaccination, Internet Panel Survey, United States, November 2017.
Grohskopf LA, Sokolow LZ, Broder KR, Emmanuel B. Walter EB, Fry AM and Jernigan DB. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices-United States, 2018–19 Influenza Season Recommendations and Reports. Aug. 24, 2018; 67(3);1-20.

Vaccine Supply for the 2018-2019 Season

The CDC provides the following Q&A addressing vaccine Supply for 2018-2019 season:

Q: How much influenza vaccine is projected to be available for the 2018-2019 influenza season?
A: Flu vaccine is produced by private manufacturers, so supply depends on manufacturers. Vaccine manufacturers have projected that they will supply as many as 163 million to 168 million doses of flu vaccine for the 2018-2019 season.

Q: How much thimerosal-free influenza vaccine is expected to be available for the 2018-2019 season?
A: For the 2018-2019 season, manufacturers will produce influenza vaccines containing thimerosal and some vaccines that do not contain thimerosal. For the 2018-2019 season, only multidose vial presentations of influenza vaccines contain thimerosal. More than 80 percent of projected vaccine supply produced for the 2018-2019 flu season will be thimerosal-free (i.e., preservative-free).

Q: How much quadrivalent vaccine is expected to be available for the 2018-2019 season?
A: For the 2018-2019 season, manufacturers will produce both trivalent (three-component) and quadrivalent (four-component) influenza vaccines. More than 80 percent of the projected vaccine supply produced for the 2018-2019 flu season will be quadrivalent (4-component) vaccines. The remaining vaccine will be trivalent, including the high-dose and adjuvanted flu vaccines, as well as one brand of standard-dose inactivated vaccine.

Q: How much of the U.S. flu vaccine supply for 2018-2019 will be produced using egg-based manufacturing?
A: Approximately 85 percent of the projected vaccine supply produced for the 2018-2019 flu season will be produced using egg-based manufacturing technology. The remaining vaccine will be produced using cell-based and recombinant technology.

Q: Can I still buy influenza vaccine for the 2018-2019 season?
A: Influenza vaccine pre-booking typically occurs between January and March, though most preparations of vaccine should still be available for purchase. Providers should contact distributors and local vendors about remaining supply. In addition, beginning in early October each year, information about manufacturers and distributors who still have influenza vaccine available for sale can be found at http://www.preventinfluenza.org/ivats/. Updates on the distribution of influenza vaccine doses for the 2018-2019 season will be provided as the season progresses.

Q: What can be anticipated in terms of the timing of vaccine availability for the 2018-2019 season?
A: The timing of vaccine availability depends on when production is completed. Influenza vaccine shipments will continue through October and November until all of the vaccine is distributed.

Q: Are all influenza vaccines the same?
A: All influenza vaccines contain antigen derived from the same influenza viruses, with the one difference being that trivalent vaccines have three different antigens and quadrivalent vaccines have four different antigens (the same three that are in the trivalent vaccines, plus one more). However, aside from the antigen composition, the different influenza vaccine preparations have different indications as licensed by the FDA. Each is licensed for a specific age range. All recipients should receive a vaccine that is appropriate for their age. In addition, LAIV is not recommended for use in some populations