Study Links 23-Valent Pneumococcal Vaccine to Injection Site Necrosis

Immunization for pneumococcal disease may lead to injection site necrosis, according to the results of a study published in JAMA Internal Medicine.

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The study authors noted that the Vaccine Adverse Event Reporting System (VAERS) system uses passive surveillance to allow patients to report adverse events (AEs) related to vaccines they were administered. Because the general public can self-report these AEs, additional investigations are required to assess and confirm these issues.

VAERS is has been found to be an effective measure for the FDA and CDC to monitor vaccines post-marketing, according to the study. The researchers examined VAERS events related to the 23-valent pneumococcal vaccine (Pneumovax 23; Merck) for this study.

Pneumococcal disease can occur in people of any age but commonly occurs in children and adults over 65 years of age. Vaccination recommendations for the prevention of pneumococcal disease are regularly changing, with all updates posted by the Centers for Disease Control & Prevention (CDC). However, specific situations can warrant vaccination against pneumococcal disease across most ages.

There are currently 4 pneumococcal vaccines approved by the FDA in the United States—3 conjugate and 1 polysaccharide vaccine. Polysaccharide vaccines are composed only of the sugar component, the capsule, of the bacteria they protect against to elicit an immune response. In conjugate vaccines, the sugar component is attached to a carrier protein to elicit a stronger immune response.

In 2020, the FDA reported a safety signal regarding injection site necrosis after administration of the 23-valent vaccine.

The investigators reviewed data from submitted medical records, clinician notes, and pathology reports. They defined cases using adapted criteria for a local reaction at or near the injection site and calculated a reporting rate incorporating vaccine distribution data from the manufacturer.

The researchers examined 104 VAERS complaints regarding skin necrosis. Of these reports, 48 met the case definition.

“Of these cases, most were for skin necrosis (n = 43), 5 of which also included fat necrosis. The remaining cases were necrosis of fascia (n = 2); fat and fascia (n = 1); fat, fascia, and muscle (n = 1); and muscle (n = 1),” the study authors wrote. “One-half of the 48 cases were reported from foreign countries and one-half were from the US. In 23 cases (47.9%), the reactions were serious, including 1 fatality (unrelated to vaccination). Seventeen patients (35.4%) required hospitalization and 26 (54.2%) required surgical intervention, most commonly debridement. Eight patients (16.7%) underwent multiple surgical procedures, and 3 (6.3%) required a skin graft.”

According to the study, the injection site necrosis reporting rate was fewer than 0.2 cases per 1 million vaccine doses administered. The investigators also conducted a search of the literature showing 2 cases of injection site necrosis following administration of the 23-valent pneumococcal vaccine. The study authors noted an update to the vaccine packaging as well as its overall safety profile.

“The Pneumovax 23 US package insert has been updated to include injection site necrosis in section 6.2, Post-Marketing Experience,” the authors wrote. “The overall benefit-risk balance for this vaccine remains favorable.”

Pneumococcal disease, defined as any type of illness caused by Streptococcus pneumoniae bacteria, is one of the leading causes of infectious mortality worldwide.Pneumococcal disease consists of pneumonia, meningitis, bacteremia, sinusitis, and otitis media.

Pneumococcal vaccines aid in protection against 100-plus serotypes of pneumococcal bacteria. Pneumococcal meningitis, bacteremia, and sinusitis, while still under the umbrella term of “pneumococcal disease,” have differing treatment options and are unlikely to be seen in the outpatient setting.

Reference

Day B, Thompson D, Mba-Jonas A, Alimchandani M. Reports of Injection Site Necrosis After 23-Valent Pneumococcal Vaccine Use. JAMA Intern Med. Published online July 03, 2023. doi:10.1001/jamainternmed.2023.2146