Updates in Pharmacy-Based Immunization Practices

During a virtual session at the American Pharmacists Association (APhA) 2021 Annual Meeting and Exposition, which was held March 12-15, experts provided updates in pharmacy-based immunizations. Stephan L. Foster, PharmD, APhA’s liaison to the CDC’s Advisory Committee on Immunization Practices, and Jeffrey Goad, PharmD, professor and chair of the Department of Pharmacy Practice at Chapman University School of Pharmacy in Irvine, California, discussed the evolving practice of pharmacy-based immunization from COVID-19 vaccines and common routine immunizations to upcoming vaccines in the pipeline.¹ 

Schedule Changes

Foster and Goad presented the recent updates to immunization schedules for children, adolescents, and adults. The 2021 childhood immunization schedule included the following changes:²

• Influenza: Revised to reflect the recommendations for the 2020-21 season. The Special situationssection was updated with language for individuals who have egg allergy with symptoms other than hives. In addition, the circumstances under which the live attenuated influenza vaccine (LAIV4) should not be used were updated to include children younger than 2 years and more detailed information on the use of LAIV4 after the receipt of influenza antiviral medications.
• Meningococcal groups A, C, W, and Y (Men ACWY): MenACWY-TT (MenQuadfi) has been added as an option. In addition, the Special situations section has been updated with information on the recommendations for use of MenACWY-CRM (Menveo) in infants who received dose 1 at age 3 to 6 months.

Additionally, edits were made in the Notes section to improve readability and clarification of the schedule for diphtheria, tetanus, pertussis, haemophilus influenzae type b, hepatitis A, hepatitis B, human papillomavirus (HPV), pneumococcal 13-valent conjugate, and tetanus, diphtheria, and acellular pertussis (Tdap) vaccines.²

In the adult immunization schedule, changes also included edits to tables and notes for hepatitis A, hepatitis B, HPV, influenza, Men ACWY, meningococcal B, pneumococcal, Tdap, and zoster vaccines. The hepatitis B vaccination recommendations were revised to recommend shared clinical decision making (SCDM) for individuals with diabetes 60 years and older. Additionally, SCDM was also included for the HPV vaccine for individuals aged 27 to 45 years.³ 

For both adult and childhood vaccination schedules, ACIP added notes to recommend the use of COVID-19 vaccines within the scope of the emergency use authorization or biologics license application for the particular vaccine.^2,3

COVID-19

Developments around COVID-19 vaccines are constantly changing, making it imperative for pharmacists to stay up to date. Currently authorized vaccines in the United States include Pfizer-BioNTech’s BNT162b2, Moderna’s mRNA-1273, and Johnson & Johnson’s Ad26.COV2.S. AstraZeneca’s viral vector vaccine AZD1222 may be another vaccine on the horizon in the coming weeks. Novavax’s NVX-CoV2373, a protein subunit vaccine, is also in phase 3 trials.¹

Pharmacists must be cognizant of the differences in vaccine doses and storage among all vaccines.

Currently, the CDC has no preference as to which of the COVID-19 vaccines is used, but none of the vaccines should be interchanged for the series. However, if different vaccines are accidentally used for the first and second doses, no extra doses are required. Additionally, COVID-19 vaccines were not studied simultaneously with the administration of other vaccines. Therefore, the CDC recommends avoiding administering other vaccines within 14 days of a COVID-19 vaccine, unless the benefits are deemed to outweigh the potential risks.¹

Influenza

The presenters provided an overview of available influenza vaccines and updated virus selection for the 2021-2022 vaccines. The World Health Organization’s recommendations for the composition of quadrivalent flu virus vaccines for the 2021-2022 season include the following:¹

Egg-based vaccines

1. an A/Victoria/2570/2019 (H1N1)pdm09-like virus,
2. an A/Cambodia/e0826360/2020 (H3N2)-like virus,
3. a B/Washington/02/2019 (B/Victoria lineage)-like virus, and
4. a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

Cell- or recombinant-based vaccines

1. an A/Wisconsin/588/2019 (H1N1)pdm09-like virus,
2. an A/Cambodia/e0826360/2020 (H3N2)-like virus,
3. a B/Washington/02/2019 (B/Victoria lineage)-like virus, and
4. a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

On March 5, 2021, the FDA approved Flucelvax (Seqirus) for an expanded indication for use in individuals 2 years and older.⁴ Flucelvax is the only cell-based influenza vaccine that has been licensed by the FDA for use in the United States. Cell-based flu vaccine production does not use flu viruses grown in eggs, and therefore it allows the vaccine to avoid egg adaptation.^1,5 The vaccine was initially approved in May 2016 for individuals 4 years and older.¹

Other Vaccines Updates

Pneumococcal

Higher-valent pneumococcal conjugate vaccines are anticipated for license in June 2021 and July 2021 for Pfizer’s 20-valent pneumococcal conjugate (PCV20) and PCV15 (Merck), respectively. Additionally, licensure for children is anticipated for Q2 to Q3 2022 for PCV15 or mid-2023 for PCV20. Both PCV15 and PCV20 are well tolerated and have a safety profile similar to PCV13 (Pfizer). Both vaccines are immunogenic, with PCV15 eliciting an immunological response superior for serotype 3 at 30 days post vaccination. A pneumococcal work group was formed by ACIP to review considerations for use of both higher-valent vaccines in the general population of US adults and in adults with certain underlying conditions.¹

Herpes Zoster

The CDC recommends that healthy adults 50 years and older receive 2 doses of the recombinant zoster vaccine (RZV, Shingles; GlaxoSmithKline), separated by 2 to 6 months, to prevent shingles and complications from the disease.⁶

At the October 2020 ACIP meeting, officials presented that RZV post-licensure safety monitoring in the Vaccine Adverse Event Reporting System (VAERS) are generally consistent with the safety profile observed in prelicensure clinical trials, including for the risk of Guillain-Barre syndrome (GBS). Additionally, Vaccine Safety Datalink (VSD) data from postlicensure safety monitoring showed that the previous preliminary safety signal for Bell’s palsy did not persist. There was also no sustained evidence of increased risk of GBS among RZV recipients. An overall increased risk of GBS was identified in a review of GBS cases following herpes zoster infections from 2010 to 2018.¹ A working group is reviewing evidence regarding the use of RZV in immunocompromised adults.¹

References

• Foster SL, Goad J. Your annual immunization update: what’s new and what’s to come. Presented at: American Pharmacists Association 2021 Annual Meeting and Exposition; March 12-15, 2021; virtual. Accessed March 12, 2021. https://apha2021.pharmacist.com/2021/apha2021/agenda.asp?pfp=BrowsebyDay 
• Wodi AP, Ault K, Hunter P, McNally V, Szilagyi PG, Bernstein H. Advisory Committee on Immunization Practices recommended immunization schedule for children and adolescents aged 18 years or younger – United States, 2021. MMWR Morb Mortal Wkly Rep. 2021;70(6):189-192. doi:10.15585/mmwr.mm7006a1
• Freedman MS, Ault K, Bernstein H. Advisory Committee on Immunization Practices recommended immunization schedule for adults aged 19 years or older – United States, 2021. MMWR Morb Mortal Wkly Rep. 2021;70(6):193-196. doi:10.15585/mmwr.mm7006a2
• Seqirus announces U.S. FDA approval of expanded age indication of its cell-based quadrivalent influenza vaccine for people two years of age and older. News release. BioSpace. March 5, 2021. Accessed March 17, 2021. https://www.biospace.com/article/releases/seqirus-announces-u-s-fda-approval-of-expanded-age-indication-of-its-cell-based-quadrivalent-influenza-vaccine-for-people-two-years-of-age-and-older/ 
• Cell-based flu vaccines. CDC. Updated January 25, 2021. Accessed March 17, 2021. https://www.cdc.gov/flu/prevent/cell-based.htm 
• Shingrix recommendations. CDC. Updated October 5, 2020. Accessed March 17, 2021. https://www.cdc.gov/vaccines/vpd/shingles/hcp/shingrix/recommendations.html