Assessing the immunogenicity of three different inactivated polio vaccine schedules for use after oral polio vaccine cessation, an open label, phase IV, randomized controlled trial. Issue 40 (24th September 2021)

• Record Type: Journal Article
• Authors: Zaman, Khalequ; Kovacs, Stephanie D.; Vanderende, Kristin; Aziz, Asma; Yunus, Mohammed; Khan, Sara; Snider, Cynthia J.; An, Qian; Estivariz, Concepcion F.; Oberste, M. Steven; Pallansch, Mark A.; Anand, Abhijeet
• Is Part Of: Vaccine. Volume 39:Issue 40(2021)
• Page Start: 5814
• Page End: 5821
• Publication Date: 2021-09-24
• Subjects: Poliovirus -- Inactivated poliovirus vaccine -- Immunization schedule; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2021.08.065
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Poliovirus eradication endgame requires IPV-only immunization schedules. A 14-week/9-month IPV schedule is superior to a 6 and 14-week schedule. A 14-week/9-month and 6-week/9-month schedules achieved a cumulative immune response of >=98%. Findings support current SAGE guidelines for IPV immunization schedules. Abstract: Background: After global oral poliovirus vaccine (OPV) cessation, the Strategic Advisory Group of Experts on Immunization (SAGE) currently recommends a two-dose schedule of inactivated poliovirus vaccine (IPV) beginning ≥14-weeks of age to achieve at least 90% immune response. We aimed to compare the immunogenicity of three different two-dose IPV schedules started before or at 14-weeks of age. Methods: We conducted a randomized, controlled, open-label, inequality trial at two sites in Dhaka, Bangladesh. Healthy infants at 6-weeks of age were randomized into one of five arms to receive two-dose IPV schedules at different ages with and without OPV. The three IPV-only arms are presented: Arm C received IPV at 14-weeks and 9-months; Arm D received IPV at 6-weeks and 9-months; and Arm E received IPV at 6 and 14-weeks. The primary outcome was immune response defined as seroconversion from seronegative (<1:8) to seropositive (≥1:8) after vaccination, or a four-fold rise in antibody titers and median reciprocal antibody titers to all three poliovirus types measured at 10-months of age. Findings: Of the 987 children randomized to Arms C, D, and E, 936 were included in the intention-to-treat analysis. At 10-months, participants in Arm C (IPV at 14-weeks and 9-months) had ≥99% cumulative immune response to all three poliovirus types which was significantly higher than the 77–81% observed in Arm E (IPV at 6 and 14-weeks). Participants in Arm D (IPV at 6-weeks and 9-months) had cumulative immune responses of 98–99% which was significantly higher than that of Arm E (p value < 0.0001) but not different from Arm C. Interpretation: Results support current SAGE recommendations for IPV following OPV cessation and provide evidence that the schedule of two full IPV doses could begin as early as 6-weeks.