Home Medizin Impfstoffe sind für schwangere Frauen mit HIV sicher, zeigen jedoch eine verminderte Immunantwort

Impfstoffe sind für schwangere Frauen mit HIV sicher, zeigen jedoch eine verminderte Immunantwort

von NFI Redaktion

In a study recently published in the journal eClinicalMedicine, researchers conducted a meta-analysis on the immunogenicity and safety of vaccines for pregnant women with HIV infections (PWLWH) and compared their immunogenicity with those without HIV infections (PWWH).

Improved access to lifelong combination antiretroviral therapy (cART) has significantly contributed to the global reduction of mother-to-child HIV transmission. HIV-exposed, uninfected (HEU) infants have a higher burden of infectious diseases than HIV-unexposed and uninfected (HUU) infants. Vaccinating PWLWH individuals could potentially decrease the severity of infectious diseases in early infancy. However, previous reports suggest that maternal vaccines administered to PWLWH may be less immunogenic than those administered to PWWH. Most HEU children live in low- and middle-income countries, especially in sub-Saharan Africa (SSA), where the HIV burden is highest. The World Health Organization (WHO) recommends tetanus vaccination during pregnancy, and insights from clinical studies confirm the safety and immunogenicity of other maternal vaccines. However, there is limited data on the safety and immunogenicity in pregnant women.

Study: The safety and immunogenicity of vaccines administered to pregnant women with HIV: a systematic review and meta-analysis. Image credit: Hit Stop Media / Shutterstock








About the Study

In their meta-analysis, researchers examined the immunogenicity and safety of vaccines for pregnant women with HIV exposure.

The team searched the databases Embase, MEDLINE, Web of Science, Cochrane, and Virtual Health Library from the start of the study until January 31, 2022, and re-conducted the search between February 1, 2022, and September 6, 2023, without language restrictions. Additionally, they searched the references of relevant studies to identify additional records. The study included observational studies and randomized clinical trials comparing vaccines administered to pregnant women with HIV infections and groups of non-HIV-infected women. They excluded animal studies, reviews, conference abstracts, and case series. Two researchers independently reviewed titles and abstracts, and a third researcher resolved discrepancies.

For the analysis, the researchers followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. They used the Newcastle-Ottawa Scale (NOS) to assess the methodological quality of non-randomized controlled trials. Three researchers assessed the risk of biases related to random sequence generation, allocation concealment, blinding of personnel and participants, blinding of outcome assessment, selective reporting, and incomplete outcome data. They assessed publication bias using funnel plot asymmetries.

The team performed a random-effects model for the meta-analyses and evaluated geometric mean titers (GMT) to calculate effect sizes using the inverse variance-weighted method and present them as mean differences. They used the I2 statistic to assess study heterogeneity and conducted group-stratified analyses, including HIV status and vaccine subtypes.

Results

The initial data search yielded 96,160 records, of which 75 underwent full-text screening, and 12 were suitable for meta-analysis, including 3,744 pregnant women, of which 1,714 were PWLWH. The study identified three vaccines: those against Group B Streptococcus (GBS), influenza viruses, and pneumococci. They assessed the risk of bias overall as low, though the bias due to blinding of outcome assessment was unclear.

Five studies involving 3,456 PWLWH women reported safety outcomes, with no increase in adverse events reported in PWLWH compared to PWWH. The GMT rise from baseline to week 28-35 post-vaccination ranged in hemagglutination units between 12 and 239. The combined geometric mean difference of hemagglutination inhibition titers (HAI) post-influenza vaccination was 56. The increase was lower in PWLWH compared to PWWH: -142. The team observed the greatest difference in women receiving B strains (-166) and the negligible difference in women receiving A/H3N1 vaccinations (-112).

One study documented one or more severe local reactions in four percent of PWLWH, while 19% experienced one or more severe systemic reactions one week post-vaccination. Compared to PWWH, five percent reported one or more severe local reactions and 15% reported one or more severe systemic reactions. One study documented an increased frequency of injection site adverse events in double-dose influenza vaccinations in pregnant women living with HIV infections. The most common serious adverse event was preterm birth, with the rate higher in pregnant HIV-infected women compared to non-HIV-infected women.

Five studies examined the immunogenicity of pneumococcal, influenza, and GBS vaccines. All reported increased antibody titers four weeks post-vaccination in PWLWH compared to baseline. However, the antibody titers were lower compared to PWWH. Three studies on influenza vaccinations provided sufficient comparison data for meta-analytical investigations, stratified by vaccine subtypes (A/H1N1 virus, A/H3N2 virus, B/Victoria virus, and B/Yamagata virus). The mean differences in antibody titers 28-35 days post-influenza vaccination were significantly higher in PWLWH compared to PWWH.

Overall, the study results indicate limited data on the immunogenicity and safety of vaccines administered to pregnant women living with HIV infections. There was no difference in vaccine safety between PWLWH and PWWH for influenza, pneumococcal, and GBS investigational vaccines, but there was a significant increase in antibody titers four weeks post-vaccination; however, the increase in PWLWH was lower compared to PWWH. The findings underscore the potential challenges for vaccination policies in high HIV burden countries and the need to include PWLWH in maternal vaccine studies to build confidence in vaccination.

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