Compared with HIV-negative individuals, HIV-positive adults often have an increased risk of infection or experience more severe morbidity following exposure to vaccine-preventable diseases.
- a lower threshold for extending indications and offering vaccination may be appropriate relative to the general population
- immune responses to vaccination are often sub-optimal in HIV-positive patients, and while these improve with ART, they often remain lower and decline more rapidly than in HIV-negative individuals
- many of these vaccines still afford protection and for some vaccines it is possible to improve immunogenicity by offering modified vaccine schedules, with higher or more frequent doses, without compromising safety
In HIV positive patients:
- non-replicating vaccines - can be used safely e.g. whole inactivated, polysaccharide, conjugated and subunit vaccines, or virus-like particles
- may be used in pregnancy and during breastfeeding if there is a significant risk of infection
- replicating (live) vaccines - traditionally contraindicated
- antiretroviral therapy (ART) induced immunorestoration reduces the risk of adverse events, in many cases shifting the risk–benefit ratio in favour of vaccination
- adults with CD4 cell counts <200 cells/μL
- must not be given replicating vaccines due to a potential risk of vaccine-associated disease
- when indicated, vaccination should be postponed until the CD4 cell count has improved on ART
- adults with a CD4 cell count of 200–350 cells/μL
- clinical judgment should be used to guide the use of replicating vaccines in these patients
- if exposure is likely, natural infection often carries a greater risk of adverse outcomes than vaccination
- a suppressed plasma HIV-1 RNA (viral) load on ART increases the safety and immunogenicity of vaccination in this group
- co-administration of multiple replicating vaccines is not recommended in HIV-positive adults due to uncertainties over safety, immunogenicity and efficacy. An interval of at least 4 weeks between vaccinations is recommended
- replicating vaccines (except yellow fever) should be administered at least 14 days before or 3 months after the administration of antibody-containing blood products, because passively acquired antibodies may interfere with the response to the vaccine
- are contraindicated in pregnancy, although in most cases the theoretical risk to the developing fetus is expected to be low
Travel vaccines:
- when vaccinating travellers, consider destination, itinerary, length of stay and planned activities equally in both HIV-positive and HIV-negative travellers.
- HIV-positive vaccine recipients should be advised that the levels and duration of vaccine-induced protection might be reduced relative to HIV-negative individuals
- importance of additional measures of protection (e.g. hand washing, against insect bites, food hygiene) should be emphasised
Transient, clinically non-significant increases in viral load have been reported in HIV-positive persons after the administration of several vaccines.
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