Effect of Maternal Vaccination of PCV-10, PPV-23 or Placebo on the Immunogenicity of PCV-10 in HIV-exposed Uninfected Infants: A Randomized Clinical Trial

BACKGROUND

The effect of pneumococcal vaccination of mothers with HIV on infant responses to childhood vaccination has not been studied. We compared the immunogenicity of PCV-10 in HIV-exposed uninfected infants born to mothers who received PCV-10, PPV-23 or placebo during pregnancy.

METHODS

Antibody levels against seven serotypes were measured at birth, before the 1 st and 2 nd doses of PCV-10 and after the completion of the 2-dose regimen in 347 infants, including 112 born to mothers who received PPV-23, 112 PCV-10, and 119 placebo during pregnancy. Seroprotection was defined by antibody levels ≥0.35µg/ml.

RESULTS

At birth and 8 weeks of life, antibody levels were similar in infants born to PCV-10- or PPV-23-recipient mothers and higher than infants of placebo-recipient mothers. After the last dose of PCV-10, infants in the maternal PCV-10 group had significantly lower antibody levels against five serotypes compared to infants in the maternal PPV-23 group; against three serotypes compared to infants in the maternal placebo group; and did not have higher antibody levels against any serotype. The seroprotection rate against seven serotypes was 50% in infants in the maternal PCV-10 compared to 71% in each of the maternal PPV-23 and placebo groups (p<0.0001).

CONCLUSIONS

Administration of PCV-10 during pregnancy was associated with decreased antibody responses to PCV-10 and seroprotection rates in infants. Considering that PCV-10 and PPV-23 had similar immunogenicity in pregnant women with HIV and that administration of PPV-23 did not affect the immunogenicity of PCV-10 in infants, PPV-23 in pregnancy may be preferred over PCV-10.

Immunogenicity of conjugated and polysaccharide pneumococcal vaccines administered during pregnancy or postpartum to women with HIV

BACKGROUND

Pneumococcal vaccination is recommended in people with HIV prioritizing PCV. We compared the immunogenicity of PCV-10 and PPV-23 administered antepartum or postpartum.

METHODS

This double-blind study randomized 346 pregnant women with HIV on antiretrovirals to PCV-10, PPV-23, or placebo at 14-34 weeks gestational age. Women who received placebo antepartum were randomized at 24 weeks postpartum to PCV-10 or PPV-23. Antibodies against seven serotypes common to both vaccines and one serotype only in PPV-23 were measured by ELISA/chemiluminescence; B- and T-cell responses to serotype-1 by FLUOROSPOT; and plasma cytokines/chemokines by chemiluminescence.

RESULTS

Antibody responses were higher after postpartum versus antepartum vaccination. PCV-10 generated lower antibody levels than PPV-23 against four and higher against one of seven common serotypes. Additional factors associated with high post-vaccination antibody concentrations were high pre-vaccination antibody concentrations and CD4+ cells; low CD8+ cells and plasma HIV RNA; and several plasma cytokines/chemokines. Serotype-1 B- and T-cell memory did not increase after vaccination.

CONCLUSIONS

Antepartum immunization generated suboptimal antibody responses, suggesting that postpartum booster doses may be beneficial and warrant further studies. Considering that PCV-10 and PPV-23 had similar immunogenicity, but PPV-23 covered more serotypes, the use of PPV-23 may be prioritized in women with HIV on ART.

Safety, immunogenicity, and transplacental antibody transport of conjugated and polysaccharide pneumococcal vaccines administered to pregnant women with HIV: a multicentre randomised controlled trial

BACKGROUND

Pneumococcus remains an important cause of morbidity in pregnant women with HIV and their infants. We compared the safety and immunogenicity of PCV-10 and PPV-23 with placebo administered in pregnancy.

METHODS

This double-blind, multicentre, randomised controlled trial was done at eight outpatient clinics in Brazil. Eligible participants were adult women with HIV who were pregnant at a gestational age between 14 weeks and less than 34 weeks and who were taking antiretroviral therapy at study entry. Participants were randomly assigned (1:1:1) to receive either PCV-10, PPV-23, or placebo. Participants and study teams were unaware of treatment allocation. Antibodies against seven vaccine serotypes in PCV-10 and PPV-23 were measured by ELISA. The primary outcomes were maternal and infant safety assessed by the frequency of adverse events of grade 3 or higher; maternal seroresponse (defined as ≥2-fold increase in antibodies from baseline to 28 days after immunisation) against five or more serotypes; and infant seroprotection (defined as anti-pneumococcus antibody concentration of ≥0·35 μg/mL) against five or more serotypes at 8 weeks of life. The study was powered to detect differences of 20% or higher in the primary immunological outcomes between treatment groups. This trial is registered with ClinicalTrials.gov, NCT02717494.

FINDINGS

Between April 1, 2016, and Nov 30, 2017, we enrolled 347 pregnant women with HIV, of whom 116 were randomly assigned to the PCV-10 group, 115 to the PPV-23 group, and 116 to the placebo group. One participant in the PCV-10 group did not receive the vaccine and was excluded from subsequent analyses. The frequency of adverse events of grade 3 or higher during the first 4 weeks was similar in the vaccine and placebo groups (3% [90% CI 1-7] for the PCV-10 group, 2% [0-5] for the PPV-23 group, and 3% [1-8] for the placebo group). However, injection site and systemic grade 2 adverse reactions were reported more frequently during the first 4 weeks in the vaccine groups than in the placebo group (14% [9-20] for the PCV-10 group, 7% [4-12] for the PPV-23 group, and 3% [1-7] for the placebo group). The frequency of grade 3 or higher adverse effects was similar across maternal treatment groups (20% [14-27] for the PCV-10 group, 21% [14-28] for the PPV-23 group, and 20% [14-27] for the placebo group). Seroresponses against five or more serotypes were present in 74 (65%) of 114 women in the PCV-10 group, 72 (65%) of 110 women in the PPV-23 group, and none of the 113 women in the placebo group at 4 weeks post vaccination (p<0·0001 for PPV-23 group vs placebo and PCV-10 group vs placebo). Seroresponse differences of 20% or higher in vaccine compared with placebo recipients persisted up to 24 weeks post partum. At birth, 76 (67%) of 113 infants in the PCV-10 group, 62 (57%) of 109 infants in the PPV-23 group, and 19 (17%) of 115 infants in the placebo group had seroprotection against five or more serotypes (p<0·0001 for PPV-23 vs placebo and PCV-10 vs placebo). At 8 weeks, the outcome was met by 20 (19%) of 108 infants in the PCV-10 group, 24 (23%) of 104 infants in the PPV-23 group, and one (1%) of 109 infants in the placebo group (p<0·0001). Although a difference of 20% or higher compared with placebo was observed only in the infants who received PPV-23 at 8 weeks of life, the difference between the two vaccine groups was not appreciable.

INTERPRETATION

PCV-10 and PPV-23 were equally safe and immunogenic in pregnant women with HIV and conferred similar levels of seroprotection to their infants. In areas in which childhood PCV administration decreased the circulation of PCV serotypes, PPV-23 administration to pregnant women with HIV might be more advantageous than PCV by virtue of including a broader range of serotypes.

FUNDING

Eunice Kennedy Shriver National Institute of Child Health and Human Development.

TRANSLATION

For the Portuguese translation of the abstract see Supplementary Materials section.