Research

GBS6 in treated maternal HIV: antibodies transferred, protection untested

NICU360 Evidence Desk·8 min read·00

In 300 Ugandan pregnancies, GBS6 antibody responses and infant transfer looked similar with well-controlled HIV. Protection and uncommon harms remain untested.

THE HOT TAKE

The study was not powered to detect uncommon adverse events with a prevalence of less than 10%.
— Mboizi et al., PREPARE WP4

PREPARE WP4 randomised 300 low-risk pregnant women across five antenatal facilities in Kampala: 150 living with HIV and 150 without HIV. At 27+0 to 35+6 weeks, they received one intramuscular dose of investigational GBS6, containing 20 μg of each of six capsular polysaccharides, or saline placebo. All 300 contributed to the safety analysis; 298 delivery outcomes yielded 293 liveborn infants, with follow-up scheduled through 12 months.

From randomisation to infant follow-up

1
300 women randomised
Double-blind, placebo-controlled phase 2 trial, stratified by maternal HIV status.
2
150 received GBS6; 150 received placebo
GBS6: 76 without HIV and 74 with HIV. Placebo: 74 without HIV and 76 with HIV.
3
298 delivery outcomes
Two participants withdrew before delivery; five stillbirths were recorded.
4
293 liveborn infants
All entered infant safety follow-up, with immunogenicity denominators varying by visit and sample availability.

THE ANTIBODY SIGNAL

Maternal anti-GBS IgG one month after GBS6 (GMC, μg/mL)

Was this worth carrying into your next shift?

Your reaction stays connected to your NICU360 profile.

Comments

Join the conversation

Loading conversation…

Serotype	Well-controlled HIV, μg/mL (95% CI)	Without HIV, μg/mL (95% CI)	P value
Ia	12.02 (6.42–22.50)	9.38 (5.06–17.41)	0.575
Ib	3.71 (2.12–6.48)	2.52 (1.35–4.71)	0.362
II	19.50 (12.93–29.41)	17.92 (11.76–27.31)	0.776
III	4.38 (2.54–7.55)	5.64 (3.66–8.70)	0.469
IV	4.26 (2.78–6.53)	4.53 (2.88–7.13)	0.842
V	0.49 (0.34–0.70)	0.52 (0.31–0.85)	0.870

Outcome	GBS6	Placebo	How to read it
Maternal participants with ≥1 serious adverse event	43/150	43/150	101 events occurred in 86 women overall
Infants with ≥1 serious adverse event	19/147	25/146	55 events occurred in 44 infants overall
Stillbirths among available delivery outcomes	1/148	4/150	Descriptive; the trial was not powered for this outcome
Infant deaths in the safety population	1/147	1/146	One death in each arm; both judged unrelated

GBS6 in treated maternal HIV: antibodies transferred, protection untested

THE HOT TAKE

300 women randomised

150 received GBS6; 150 received placebo

298 delivery outcomes

293 liveborn infants

THE ANTIBODY SIGNAL

Comments

THE SAFETY READ

WHAT THIS DOES—AND DOES NOT—ADD

WHY TREATED HIV MATTERS

LIMITS AND VERSION WARNINGS

PRACTICAL TAKEAWAY