A pioneering study from Johns Hopkins Medicine reveals that immunocompromised individuals produce fewer antibodies after receiving RSV vaccines. This significant finding underscores the need for further research to enhance vaccine efficacy for vulnerable populations.
People over 60 with weakened immune systems produce fewer protective antibodies against respiratory syncytial virus (RSV) following vaccination, according to a new study by Johns Hopkins Medicine researchers. The findings shine a light on the potential need for tailored vaccination strategies for immunocompromised individuals, such as organ transplant recipients and those with immune system disorders.
The study, published in the Journal of the American Medical Association (JAMA), was conducted by a research team at the Johns Hopkins Transplant Research Center. Their work builds on earlier studies exploring the efficacy of COVID-19 vaccines in immunocompromised populations.
RSV, a highly contagious respiratory pathogen, poses severe risks to both young children and the elderly. The study demonstrates that older adults with compromised immune systems do not exhibit the same robust antibody responses to RSV vaccines seen in their healthy counterparts.
“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,” lead author Andrew Karaba, an assistant professor of medicine at the Johns Hopkins University School of Medicine, said 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.”
The researchers tracked 38 individuals aged 64 to 72 who self-reported as immunocompromised and received either the RSVPreF3-AS01 (Arexvy) or RSVpreF (Abrysvo) vaccine. A majority of the participants were solid organ transplant recipients on immunosuppressive medications.
Both RSV vaccines target a critical protein on the virus’s surface, aiming to increase pre-fusion F antibodies, known to neutralize RSV and prevent infection. Despite the general success of these vaccines in generating antibodies in healthy adults, the study queried why responses vary among the immunocompromised.
“We suspected that a fundamental difference in the two 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,” senior author William Werbel, an assistant professor of medicine at the Johns Hopkins University School of Medicine, said in the news release.
Arexvy contains an adjuvant, but Abrysvo does not.
“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,” added Werbel. “So, adjuvant-enhanced vaccines as a means of improving immune response in people who are immunocompromised merits further investigation in larger, more comprehensive studies.”
This study’s findings do not imply that RSV vaccines are ineffective for immunocompromised individuals, noted the researchers. The U.S. Centers for Disease Control and Prevention (CDC) recommends RSV vaccination for everyone older than 75 and for people 60 or older who are at high risk, including those who are immunocompromised.
“As with our previous work with COVID-19 vaccines [which led to recommendation that people who are immunocompromised getting additional vaccine doses to improve protection], we look forward to additional research on RSV vaccine responses that will provide guidance for optimized timing and vaccine selection for people who are immunocompromised,” Karaba added.
The study emphasizes the importance of further investigations to better understand and enhance vaccine efficacy in immunocompromised populations, potentially guiding interventions that could protect some of the world’s most vulnerable individuals.