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Study Suggests Weakened RSV Vaccine Response in Immunocompromised Individuals
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Key Takeaways
- Immunocompromised individuals show a weakened and variable antibody response to RSV vaccination compared to healthy individuals.
- Adjuvanted vaccines may enhance RSV-neutralizing antibody levels in immunocompromised populations, warranting further investigation.
Immunocompromised older adults developed fewer antibodies against RSV following vaccination compared with immunocompetent individuals.
With findings published in the Journal of the American Medical Association, researchers assessed the antibody response to respiratory syncytial virus (RSV) vaccination in older immunocompromised individuals, finding a weakened reaction compared to individuals with normal immune function.1
“We found that on average, older adults who are immunocompromised developed fewer antibodies against RSV following vaccination as compared with the very strong responses for healthy people over age 60 seen in the clinical trials used to validate the vaccines,” said study lead author Andrew Karaba, MD, PhD, assistant professor of medicine at the Johns Hopkins University School of Medicine, in a news release. “Additionally, antibody levels in people who are immunocompromised were highly variable, with some study participants showing strong increases in immunity because of the vaccines while others barely responded.”1
RSV infection poses a significant health risk to immunocompromised individuals. According to study authors, novel RSV vaccines containing the prefusion F protein demonstrated promising results among immunocompetent populations, indicating a substantial 13- to 14-fold increase in antibody titers within a month of vaccination and a high 82.6% efficacy in preventing confirmed RSV-related lower respiratory tract disease. However, limited data is available on antibody titers following RSV vaccines in immunocompromised individuals, along with the connection with vaccine effectiveness.2
A research team at Johns Hopkins Transplant Research Center conducted a prospective, national cohort study that evaluated viral vaccination and infection among individuals with self-reported immunocompromised conditions. Using research from an ongoing Johns Hopkins Medicine-led national study—the Emerging Pathogens of Concern in Immunocompromised Persons (EPOC)—the researchers followed 38 immunocompromised individuals aged 64 to 72 years who received RSVPreF3-AS01 (Arexvy; GSK) or RSVpreF (Abrysvo; Pfizer) from October 10, 2023, and followed up through July 1, 2024.2
Among the included individuals, 82% were solid organ transplant recipients and 74% taking 2 or more immunosuppressive medications. The individuals were required to have paired baseline and 4-week post-vaccination samples and no receipt of immunoglobulin products after RSV vaccination.1,3
“We suspected that a fundamental difference in the 2 vaccines—the presence or absence of an immune-stimulating chemical called an adjuvant—might play a role in the variance in immunity, so we looked at that,” said study senior author William Werbel, MD, PhD, assistant professor of medicine at the Johns Hopkins University School of Medicine, in a news release.1
The results demonstrated that preF IgG antibody titers rose from 87,292 AU/mL at baseline to 626,280 AU/mL at 2 weeks, 439,086 AU/mL at 4 weeks, and 464,170 AU/mL at 12 weeks. Additionally, the median 4-week NT50 fold rise was 6.97 and 58% achieved high-titer neutralization, according to study authors.1-3
“When we compared the antibody responses between those study participants who received Arexvy with those who got Abrysvo, we found that the group receiving the adjuvanted vaccine tended to have higher levels of RSV-neutralizing, anti-pre-fusion F antibodies,” said Werbel, in a news release. “So, adjuvant-enhanced vaccines as a means of improving immune response in people who are immunocompromised merits further investigation in larger, more comprehensive studies.”1
The findings suggest a heterogeneous antibody response to RSV vaccines in immunocompromised individuals, with a significant proportion failing to achieve adequate neutralization. While RSVA-AS01E showed some promise, low antibody levels suggest the need for optimized vaccination strategies in this vulnerable population.1-3
However, study limitations included a small sample size, a lack of cellular immune response data, and an absence of correlation with vaccine effectiveness. Additionally, the study authors noted that the findings do not suggest that RSV vaccines will not reduce RSV disease in individuals who are immunocompromised.1
