New guidelines from the Infectious Diseases Society of America (IDSA) recommend that adults and children with weakened immune systems (immunocompromise) receive an age-appropriate COVID-19 vaccine dose as soon as possible for the upcoming respiratory virus season.
The organization also urges household members and those in close contact with immunocompromised people to stay current with COVID-19 vaccinations to provide further protection. It said that patients may receive COVID-19, influenza, and respiratory syncytial virus (RSV) vaccines at the same time.
People may have an impaired immune system due to a disease such as cancer or HIV or to drugs they must take to treat conditions such as organ transplant. Patients with chronic organ dysfunction such as end-stage kidney disease and cirrhosis aren't considered in the guidance.
"Vaccines are one of the most powerful tools to prevent respiratory viral illnesses, and this protection is especially important for individuals in our communities who have impaired immune systems," Lindsey Robert Baden, MD, vice president of clinical research at Mass General Brigham and chair of the IDSA guideline panel, said in a news release.
"IDSA's guideline for COVID vaccination for individuals who are immunocompromised helps protect people who often suffer the most severe associated illnesses," he added.
The society said it will release recommendations on vaccination against flu and RSV in the coming weeks.
Post-vaccination reduction in hospitalization
The guidance is based on a systematic literature review conducted by the Center for Infectious Disease Research and Policy's (CIDRAP's) Vaccine Integrity Project and supplementary searches and evidence reviews from IDSA's guideline panel of experts. The Vaccine Integrity Project aims to safeguard US vaccine use so that it remains grounded in the best science, free from external influence. CIDRAP is the publisher of CIDRAP News.
"We were proud to work with IDSA to help provide the evidence necessary to write COVID vaccination guidelines that people who are immunocompromised can rely on to protect their health," Kevin Griffis, Vaccine Integrity Project spokesperson, told CIDRAP News.
"IDSA, the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists and the American Academy of Family Physicians have all stepped up to fill the vital need for evidence-based immunization recommendations this fall and winter, prioritizing the health of their patients, especially those at greatest risk of severe disease," he added.
IDSA panelists reviewed evidence published in the 18 to 24 months since the evidence base for the last Centers for Disease Control and Prevention (CDC) recommendations were published (the search was started in June 2024). Most of the evidence was on mRNA vaccines.
The panel included scientists who specialize in adult and pediatric infectious diseases, including the treatment of immunocompromised patients; vaccines and vaccine research; and transplant medicine.
"The panel established one clinical question for the use of each vaccine ('should [virus] vaccine vs no vaccine be used in immunocompromised patients?') and identified patient-importance outcomes for both vaccine effectiveness and adverse events (eg, hospitalization, mortality, progression to severe disease; and serious adverse events, or exacerbation of immunocompromising or autoimmune conditions, respectively)," the news release said.
With moderate-certainty evidence, the literature review found a link between COVID-19 vaccination in immunocompromised people and a reduction in related hospitalization. Vaccine effectiveness (VE) estimates, which ranged from 33% to 56% in studies, included one cohort study (VE, 46%) and four test-negative case-control studies (VE, 37%).
Less critical illness, death, healthcare use
Vaccination was tied to reductions in critical COVID-19 illness (VE, 40%) and death (VE, 61%), although the evidence was of low certainty, and COVID-related emergency department/urgent care visits (VE, 34%) and outpatient visits (VE, 40%), with moderate certainty.
Shared clinical decision-making is essential, allowing flexibility in timing and dosing to accommodate immunosuppressive therapy schedules, travel, and individual risk factors.
"For most studies, follow-up time or time since last vaccine dose was relatively short, with a median of less than two months," the guideline authors wrote. "Given that vaccine protection decreases over time, these estimates are likely to represent higher-end values."
Several adverse outcomes of interest, such as heart attack and stroke, were less common among vaccinated people. Although cases of myocarditis (inflammation of the heart muscle) were seen in the vaccinated group, the risk was lower than that in their unvaccinated counterparts, likely due to an increased risk of myocarditis due to COVID-19 infection itself. But the authors warn that this estimate was imprecise because cases were rare and because the evidence it was based on was of low certainty.
"All immunocompromised individuals aged ≥6 months should receive at least one dose of the current season’s COVID-19 vaccine, with additional doses based on prior vaccination history and clinical judgment," the guideline authors wrote. "Shared clinical decision-making is essential, allowing flexibility in timing and dosing to accommodate immunosuppressive therapy schedules, travel, and individual risk factors."
They called for future research into, for example, correlates of protection and immunogenicity (ability to provoke an immune response) thresholds for diverse immunocompromised subgroups and vaccine-protection durability and waning in the context of emerging SARS-CoV-2 variants and evolving immunosuppressive drugs.
