Safety and infectivity of two doses of live-attenuated recombinant cold-passaged human parainfluenza type 3 virus vaccine rHPIV3cp45 in HPIV3-seronegative young children.
Vaccine 2013;
31:5706-12. [PMID:
24103895 PMCID:
PMC3889708 DOI:
10.1016/j.vaccine.2013.09.046]
[Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/13/2013] [Accepted: 09/23/2013] [Indexed: 12/25/2022]
Abstract
rHPIV3cp45 vaccine was immunogenic and well-tolerated in seronegative young children.
A second dose of rHPIV3cp45 given 6 months later was restricted in those previously infected.
Antibody responses were boosted after a second dose of rHPIV3cp45.
A second dose of rHPIV3cp45 induced antibody responses in two previously uninfected children.
Background
Human parainfluenza virus type 3 (HPIV3) is a common cause of upper and lower respiratory tract illness in infants and young children. Live-attenuated cold-adapted HPIV3 vaccines have been evaluated in infants but a suitable interval for administration of a second dose of vaccine has not been defined.
Methods
HPIV3-seronegative children between the ages of 6 and 36 months were randomized 2:1 in a blinded study to receive two doses of 105 TCID50 (50% tissue culture infectious dose) of live-attenuated, recombinant cold-passaged human PIV3 vaccine (rHPIV3cp45) or placebo 6 months apart. Serum antibody levels were assessed prior to and approximately 4–6 weeks after each dose. Vaccine virus infectivity, defined as detection of vaccine-HPIV3 in nasal wash and/or a ≥ 4-fold rise in serum antibody titer, and reactogenicity were assessed on days 3, 7, and 14 following immunization.
Results
Forty HPIV3-seronegative children (median age 13 months; range 6–35 months) were enrolled; 27 (68%) received vaccine and 13 (32%) received placebo. Infectivity was detected in 25 (96%) of 26 evaluable vaccinees following doses 1 and 9 of 26 subject (35%) following dose 2. Among those who shed virus, the median duration of viral shedding was 12 days (range 6–15 days) after dose 1 and 6 days (range 3–8 days) after dose 2, with a mean peak log10 viral titer of 3.4 PFU/mL (SD: 1.0) after dose 1 compared to 1.5 PFU/mL (SD: 0.92) after dose 2. Overall, reactogenicity was mild, with no difference in rates of fever and upper respiratory infection symptoms between vaccine and placebo groups.
Conclusion
rHPIV3cp45 was immunogenic and well-tolerated in seronegative young children. A second dose administered 6 months after the initial dose was restricted in those previously infected with vaccine virus; however, the second dose boosted antibody responses and induced antibody responses in two previously uninfected children.
Collapse