677 
Serologic Responses to Recall and Neoantigens in Severely Immunocompromised HIV-infected Children Initiating HAART
Mona Rigaud*1, W Borkowsky1, P Muressan2, A Weinberg3, P Larussa4, T Fenton2, J Read5, P Jean-Philippe6, E Ferguson7, B Zimmer8, and PACTG 1006 Team
1New York Univ Sch of Med, NY, US; 2Harvard Sch of Publ Hlth, Boston, MA, US; 3Univ of Colorado Hlth Sci Ctr, Denver, US; 4Columbia Univ Mailman Sch of Publ Hlth, New York, NY, US; 5PAMA, NICD, NIH, Bethesda, MD, US; 6DAIDS, NIAID, NIH, DHHS, Bethesda, MD, US; 7PAB, DAIDS, NIAID, Bethesda, MD, US; and 8Frontier Sci & Tech Res Fndn, Amherst, NY, US
Background: Data from P1006 were analyzed to determine if
severely immunocompromised HIV-infected children
initiating HAART can mount serological responses to vaccines.
Methods: Severely immunocompromised
children (CD4% <15%) who demonstrate a reduction of >0.75 log in plasma
HIV RNA within 4 weeks of initiating HAART are randomized to 2 immunization
groups. The first group is vaccinated with a recall antigen tetanus toxoid (TT) at weeks 8, 16, and 24 and receives hepatitis A
vaccine (HepA), a neoantigen,
at weeks 32, 40, and 48. The second group is vaccinated initially with hepatitis
A followed by immunization with TT at same time points. Serological responses
measured by ELISA are evaluated. Children that demonstrate a titer of >0.1
IU/mL and >20 IU/mL are
considered serologic responders for TT and HepA,
respectively.
Results: The median titers (in IU/mL)
and number of evaluated serologic responders (SR) after immunizations are
reported in Tables I and II for TT and HepA,
respectively. TT titers and SR rates after 3 TT vaccines (week 28 in group 1 )
are higher, but not statistically different when compared with week 52 in group
2 (p >0.2 ), and week 76 in group 1
compared with week 100 in group 2 (p >0.4).
Titers after Hep A vaccines were significantly higher
at week 28 (p <0.01) in group 2
children when compared to unvaccinated children as well as when compared to group1
children (week 52) (p = 0.02). Titers
and SR were not statistically significant in group1 at week 100 compared to group2
at week 76.
|
Table 1
|
Group 1
|
Group 2
|
|
Weeks
|
Median Titer
|
SR (N)
|
Median Titer
|
SR (N)
|
|
0
|
0.11
|
10(18)
|
0.11
|
9(16)
|
|
12
|
0.51
|
13(18)
|
0.07
|
9(19)
|
|
28
|
2.98
|
14(14)
|
0.10
|
8(16)
|
|
36
|
1.37
|
15(15)
|
0.37
|
10(14)
|
|
52
|
0.69
|
11(12)
|
1.79
|
11(13)
|
|
76
|
0.43
|
12(12)
|
2.22
|
11(14)
|
|
100
|
0.21
|
6(8)
|
0.80
|
10(12)
|
|
|
|
|
|
|
|
Table 2
|
Group1
|
Group2
|
|
Weeks
|
Median Titer
|
SR(N)
|
Median Titer
|
SR(N)
|
|
0
|
7.71
|
2(18)
|
5.61
|
0(16)
|
|
12
|
7.74
|
0(18)
|
9.00
|
3(19)
|
|
28
|
6.44
|
1(14)
|
26.30
|
9(16)
|
|
36
|
8.15
|
1(15)
|
22.41
|
8(15)
|
|
52
|
146.48
|
10(12)
|
14.39
|
6(14)
|
|
76
|
102.96
|
11(13)
|
13.88
|
6(14)
|
|
100
|
31.98
|
6(8)
|
20.39
|
6(12)
|
Conclusions: Serological
response to a recall antigen is boosted after 3 doses of vaccine independent of
timing of immunization (early or late). Serological response to a neo-antigen, Hep A, seems to develop if immunization is delayed after
initiation of HAART.
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