LB-10. Immediate (Pre-Antiretroviral Treatment [ART]) vs. Delayed (≥6 Months after Starting ART) Pneumococcal Vaccination in HIV patients: Results from a Randomized Clinical Trial
Session: Poster Abstract Session: Late Breaker Posters
Saturday, October 22, 2011
Room: Poster Hall B1
Background:  In HIV infected subjects, suppression of viremia with ART leads to improved B cell function; we hypothesize that delaying immunization with pneumococcal vaccine (PV) until after patients have received antiretroviral treatment (ART) will improve the antibody responses to pneumococcal capsular polysaccharides (CPS).

Method:  Prospective, randomized, placebo controlled study.  HIV infected subjects, CD4 >200, not on ART, and no PV within last 3 years were eligible.  109 patients were randomized to receive either Immediate PV, PV prior to starting ART followed by placebo at 12 months (m) or Delayed PV, baseline placebo followed by PV at 12m (after ≥6m of ART).  IgG levels to 5 CPS were measured by ELISA pre- and 1m post- PV or placebo.  Response was defined as 2-fold post-PV IgG increase and post-PV IgG ≥1 μg/ml. Outcomes were: Pre to post-PV IgG increases, % of responders for each CPS, and % of subjects with responses to ≥2 CPS.

Result:  We are presenting results for the 43 subjects that have completed ≥13m.  Baseline characteristics were (Immediate vs. Delayed), age, 43 vs. 44 years, CD4 count, 283 vs. 432, log viral load, 4 vs. 5, and prior PV, 26 vs. 23%; at 12m CD4 was 378 vs.490 and 67% vs. 64% of subjects had viral loads <50 RNA copies/mL (no significant differences between groups at baseline or 12 m). Geometric mean (GM) IgG (μg/ml):

 

Immediate PV N=18

Delayed PV N=25

CPS

        0m            (PV)

1m

12m(Placebo)

13m

0m (Placebo)

1m

       12m         (PV)

13m

1

1.76

2.61*

1.83

1.66

2.04

2.12

2.01

2.63*

3

0.74

0.94

0.6

0.58

0.89

0.91

0.88

1.09

4

0.74

1.03*

0.81

0.77

1.09

1.03

0.85

1.07

6B

3.96

6.38

4.20

4.65

4.61

4.42

4.56

4.79

23F

1.45

2.04*

1.74

1.54

1.82

1.93

1.70

2.13*

*P<0.05 compared to pre-PV level.

There were no significant differences in pre- or post-vaccine GM IgG between groups for any CPS.  The % of responders for each CPS were (Immediate vs. Delayed): CPS 1, 22 vs. 28; CPS 3, 11 vs. 16; CPS 4, 17 vs. 16; CPS 6B, 22 vs. 8; and CPS 23F, 17 vs. 16 (P>0.05 for all CPS); % of responders to 0-1, 2-3, and 4-5 CPS were 78 vs. 76, 17 vs. 20, and 6 vs. 4, respectively (P>0.05 for all categories).

Conclusion: Overall, post-PV IgG responses to the 5 CPS tested were low and similar between the 2 groups.  Results suggest that in HIV-infected subjects with CD4 >200, delaying PV until at least 6 m of ART does not improve antibody responses to PV.


Subject Category: E. Innate and adaptive immunity to infections, including vaccine immunology

Maria C. Rodriguez-Barradas, MD1, Adriana M. Rueda, MD2, Mahwish Mushtaq, M.D3, Eddie Vargas4, Brenda Bellard4 and Jose Serpa, MD5, (1)Medicine- Infectious Disease, Michael E. DeBakey VA Medical Center and Baylor College of Medicine, Houston, TX, (2)Medicine/Infectious Diseases, Michael E. DeBakey VAMD and Baylor College of Medicine, Houston, TX, (3)Michael E. DeBakey VA Medical Center, Houston, TX, (4)Michael E. DeBakey VAMC and Baylor College of Medicine, Houston, TX, (5)Baylor College of Medicine, Houston, TX

Disclosures:

M. C. Rodriguez-Barradas, None

A. M. Rueda, None

M. Mushtaq, None

E. Vargas, None

B. Bellard, None

J. Serpa, None

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