Technically Speaking: New Adult Pneumococcal Vaccine Recommendations

On Oct. 20, 2021, ACIP voted unanimously to adopt two adult pneumococcal recommendations to help reduce the burden of disease from Streptococcus pneumoniae. These recommendations have been adopted by the director of the Centers for Disease Control and Prevention (CDC) and will be published in CDC’s Morbidity and Mortality Weekly Report (MMWR).

Pneumococcal disease burden

Invasive pneumococcal disease (IPD) is “an infection confirmed by the isolation of Streptococcus pneumoniae from a normally sterile site (e.g., blood, cerebrospinal fluid, and pleural, joint, or peritoneal fluid but not sputum),” according to UpToDate.com. In 2019 about 30,000 IPD cases and 3,000 IPD deaths occurred. Among adults who experience IPD, about 43% are 65 years of age or older and about 48% are 19- to 64-year-olds who have been diagnosed with a chronic medical condition, immunocompromising condition, cerebral spinal fluid leak, or cochlear implant. Among all people who die from IPD, more than 50% are adults. Antibiotic resistance to penicillin and other antimicrobial agents has spread rapidly in the United States, making disease prevention through vaccination increasingly important and urgent.

New vaccines, new recommendations

In recent years, adult pneumococcal vaccination has included two vaccines, a polysaccharide vaccine that provides protection against 23 pneumococcal serotypes (PPSV23) and a conjugate vaccine that provides protection against 13 serotypes (PCV13). In their article in Vaccine, Grabenstein and Manoff note that pneumococcal immune responses from infants and young children cannot be generalized to older persons, noting, “…antibody responses of adults to PPSV23 and PCV13 are generally similar 6–12 months after vaccination, serotype for serotype, for both single and multidose regimens.” (Grabenstein JD & Manoff SB. Pneumococcal vaccines in adults: assessing the evolving evidence. Vaccine. 2011 Aug 26;29(37):6149-6154)

During 2021, the FDA approved two new conjugate pneumococcal vaccines:

• PCV15 (Merck) protects against 15 serotypes — This new vaccine includes two serotypes beyond those currently included in PCV13, 22F and 33F. Both of these serotypes are included in PPSV23.
• PCV20 (Wyeth) protects against 20 serotypes — In addition to the serotypes in PCV15, this version also includes serotypes 8, 10A, 11A, 12F and 15B, all of which are also included in PPSV23.

Because the current PCV13 vaccine protects against serotypes that cause less than 30% of IPD in adults older than 65 years of age, the newer versions provide an important opportunity to better protect this susceptible age group. The two additional serotypes in PCV15 account for about 15% of cases in this age group, and those in PCV20, including the additional serotypes in PCV15, account for almost 30% of cases in this age group compared with those included in PCV13. Similar serotype profiles are seen in those with chronic medical conditions and those with immune-compromising conditions. To see more details, check the slides presented by Dr. Kobayashi during the October 2021 ACIP meeting.

The new adult pneumococcal recommendations offer an opportunity to use either of these newly approved vaccines, as described:

• Age-based recommendation: Adults 65 years of age and older who have not previously received a pneumococcal conjugate vaccine or whose previous vaccination history is unknown should receive a pneumococcal conjugate vaccine (either PCV20 or PCV15). If PCV15 is used, this should be followed by a dose of PPSV23.
• Risk-based recommendation: Adults 19 years of age and older with certain underlying medical conditions or other risk factors* who have not previously received a pneumococcal conjugate vaccine or whose previous vaccination history is unknown should receive a pneumococcal conjugate vaccine (either PCV20 or PCV15). If PCV15 is used, this should be followed by a dose of PPSV23.
  
  *Providers should refer to the pneumococcal vaccine recommendations for the complete list of relevant risk factors; however, some of the most common risk factors include alcoholism and cigarette smoking; immune-compromising conditions; diabetes mellitus and chronic conditions involving the heart, liver, lungs or kidneys; cochlear implants; cancers and some conditions that impede the spleen’s function. 

Making it real

Between 2010 and 2018, pneumococcal vaccination coverage (≥ 1 dose) increased, but remained low:

• Among adults 19–64 years of age at increased risk, coverage ranged from 18.5% to 24.5%. The average annual increase in coverage was 0.7%
• Among adults 65 years of age or older, coverage ranged from 59.7% to 69.0%. The average annual increase in coverage was 1.3%

To take full advantage of the opportunity to prevent pneumococcal disease, we need to utilize a variety of strategies, such as those recommended by the Community Preventive Services Task Force. Published in The Community Guide, these include:

• Client Reminder and Recall Systems
• Provider Assessment and Feedback
• Provider Reminders
• Standing Orders
• Health Care System-Based Interventions Implemented in Combination

Pharmacies should be a key component of the adult pneumococcal vaccination effort because of their access to and knowledge of patients eligible for pneumococcal vaccination. Their enormous contributions to the COVID-19 vaccination program have further positioned them as trusted providers of adult immunizations.

Licensure for children is anticipated in early 2022 for PCV15 and in early to mid-2023 for PCV20, according to Dr. Kobayashi’s presentation at the October 2021 ACIP meeting. It is hoped that pediatric use of the new pneumococcal conjugate vaccines will have a significant indirect effect on adult disease burden. However, we can realize that improvement sooner if we increase our efforts around directly immunizing adults. Won’t it be marvelous if someday our trainees have to ask what it was like to treat Streptococcus pneumococcus?

Resource alert!

The Immunization Action Coalition’s (IAC) web section called “Ask the Experts” offers a curated list of answers to common and difficult vaccine questions. Once the updated pneumococcal recommendations are published in the MMWR, the pneumococcal vaccine section of questions and answers will be updated. “Ask the Experts” updates, as well as other IAC resources, are announced in the weekly e-newsletter, IAC Express.

Subscribe now!