RSV vaccination benefits moms with HIV and their babies

RSV Vaccine Advances: Protecting Vulnerable Infants, Including Those with HIV

Recent data presented at the Conference on Retroviruses and Opportunistic Infections demonstrate the safety and effectiveness of maternal RSV vaccination for mothers living with HIV and their infants. This breakthrough expands the potential benefits of RSVpreF, a vaccine previously shown to protect infants for up to six months after birth, to a historically underrepresented population.

Expanding Vaccine Access to High-Risk Groups

Traditionally, pregnant women with HIV have often been excluded from vaccine trials, limiting the ability to assess vaccine performance and safety within this vulnerable group. The Pfizer-sponsored trial, involving 331 pregnant women with HIV in South Africa and their 314 infants, directly addresses this gap. The study found no contraindications or safety concerns specific to pregnant individuals living with HIV.

Robust Antibody Response and Transfer

The research, led by Emily Wasserman, MD, director of clinical development at Pfizer, revealed that the vaccine elicited robust maternal antibody responses comparable to those observed in earlier trials with HIV-negative mothers. Crucially, these antibodies were effectively transferred to infants, providing early protection against RSV. Geometric mean ratios showed a 7.6-fold increase in RSV-A antibodies and a 6.5-fold increase in RSV-B antibodies in infants’ cord blood compared to the placebo group.

Slightly Lower, Yet Significant, Infant Antibody Levels

While infant RSV neutralizing antibody titers were slightly lower than those seen in previous trials, the levels remained significant, suggesting a protective effect. Researchers are continuing to investigate the long-term effectiveness and clinical outcomes of the maternal RSV vaccine in infants born to mothers with HIV.

Safety Profile Confirmed

The study reinforced the vaccine’s favorable safety profile. Approximately 7% of women receiving the vaccine reported hypertensive disorders of pregnancy and postpartum, compared to 8.8% in the placebo group. Rates of preterm birth were also comparable (8.8% vs. 7.8%).

Future Directions: Universal RSV Protection

These findings pave the way for broader recommendations regarding maternal RSV vaccination, potentially leading to universal protection for all infants. Further research will focus on characterizing vaccine effectiveness and clinical outcomes specifically within the HIV-positive maternal population.

Expert Perspective: A Step Towards Inclusive Vaccine Strategies

Sharon Nachman, MD, Professor of Pediatrics at SUNY Stony Brook, emphasized the importance of these findings, stating, “Routine exclusion of pregnant women with HIV severely limits the ability to employ vaccines around the world. This study demonstrates that women with HIV are excited to participate in studies and that the vaccine demonstrates infant protection. We necessitate these data to help protect all children from illness associated with RSV.”

Frequently Asked Questions

• What is RSV? Respiratory Syncytial Virus (RSV) is a common respiratory virus that usually causes mild, cold-like symptoms, but can be serious for infants and young children.
• How does the maternal RSV vaccine function? The vaccine is given to pregnant individuals, stimulating their immune system to produce antibodies that are then passed on to the baby, providing early protection.
• Is the RSV vaccine safe for pregnant women with HIV? Data from a recent trial indicate the vaccine is safe and well-tolerated in pregnant women with HIV, with no recent safety concerns identified.
• How long does protection from the vaccine last? Previous studies have shown protection for up to six months after birth. Ongoing research is evaluating long-term effectiveness.

For more information:

Emily Wasserman, MD, can be reached at [email protected].

Source:

Myer L, et al. Abstract 826. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 22-25, 2026; Denver.