scholarly journals Immunogenicity of reduced-dose monovalent type 2 oral poliovirus vaccine in Mocuba, Mozambique

2020 ◽  
Author(s):  
Nilsa de Deus ◽  
Igor Paulo Ubisse Capitine ◽  
Adilson Fernando Loforte Bauhofer ◽  
Selma Marques ◽  
Marta Cassocera ◽  
...  
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Oral Poliovirus Vaccine ◽  
Advisory Group ◽  
Open Label ◽  
Small Loss ◽  
Reduced Dose ◽  
Randomized Controlled ◽  
Potential Strategy

Abstract Background Monovalent type 2 oral poliovirus vaccine (mOPV2) stockpile is low. One potential strategy to stretch the existing mOPV2 supply is to administer a reduced dose: one-drop instead of two-drops. Methods We conducted a randomized, controlled, open-label, non-inferiority trial (10% margin) to compared immunogenicity following administration of one versus two-drops of mOPV2. We enrolled 9-22-months old infants from Mocuba district of Mozambique. Poliovirus neutralizing antibodies were measured in sera collected before and one month after mOPV2 administration. Immune response was defined as seroconversion from seronegative (<1:8) at baseline to seropositive (>1:8) after vaccination or boosting titers by >4-fold for those with titers between 1:8 and 1:362 at baseline. The trial was registered at anzctr.org.au (number ACTRN12619000184178p). Results We enrolled 378 children and 262 (69%) completed per-protocol requirements. Immune response of mOPV2 was 53.6% (95% confidence interval [CI]: 44.9%-62.1%) and 60.6% (95% CI: 52.2%-68.4%) in 1-drop and 2-drops recipients, respectively. The non-inferiority margin of the 10% was not reached (difference=7.0%; 95%CI= -5.0-19.0). Conclusion A small loss of immunogenicity of reduced mOPV2 was observed. Although the non-inferiority target was not achieved, the Strategic Advisory Group of Experts on Immunization, recommended the 1-drop strategy as a dose-sparing measure if mOPV2 supplies deteriorate further.

scholarly journals Randomized Controlled Clinical Trial of bivalent Oral Poliovirus Vaccine and Inactivated Poliovirus Vaccine in Nigerian Children

2020 ◽  
Author(s):  
Beckie N Tagbo ◽  
Harish Verma ◽  
Zubairu M Mahmud ◽  
Kolade Ernest ◽  
Roosevelt O Nnani ◽  
...  
Keyword(s):  
African Country ◽  
Controlled Trial ◽  
Oral Poliovirus Vaccine ◽  
Controlled Clinical Trial ◽  
Randomized Controlled Clinical Trial ◽  
Open Label ◽  
Nigerian Children ◽  
Randomized Controlled ◽  
Sub Saharan

Abstract Background We conducted a trial in Nigeria to assess the immunogenicity of the new bOPV + IPV immunization schedule and gains in type 2 immunity with addition of second dose of IPV. The trial was conducted in August 2016-March 2017 period, well past the tOPV-bOPV switch in April 2016. Methods This was an open-label, two-arm, non-inferiority, multi-center, randomized controlled trial. We enrolled 572 infants of age ≤14 days and randomized them into two arms. Arm A received bOPV at birth, 6 and 10 weeks, bOPV+IPV at week 14 and IPV at week 18. Arm B received IPV each at 6, 10, 14 weeks and bOPV at 18 weeks of age. Results Seroconversion rates for poliovirus types 1 and 3, respectively, were 98.9% (95%CI:96.7-99.8) and 98.1% (95%CI:88.2-94.8) in Arm A, and 89.6% (95%CI:85.4-93.0) and 98.5% (95%CI:96.3-99.6) in Arm B. Type 2 seroconversion with one dose IPV in Arm A was 72.0% (95%CI:66.2-77.3), which increased significantly with addition of second dose to 95.9% (95%CI:92.8-97.9). Conclusion This first trial on the new EPI schedule in a sub-Saharan African country demonstrated excellent immunogenicity against poliovirus types 1 and 3, and substantial/enhanced immunogenicity against poliovirus type 2 after 1 to 2 doses of IPV respectively.

scholarly journals A Randomized Phase 4 Study of Immunogenicity and Safety After Monovalent Oral Type 2 Sabin Poliovirus Vaccine Challenge in Children Vaccinated with Inactivated Poliovirus Vaccine in Lithuania

2020 ◽  
Vol 223 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Ananda S Bandyopadhyay ◽  
Chris Gast ◽  
Elizabeth B Brickley ◽  
Ricardo Rüttimann ◽  
Ralf Clemens ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Oral Poliovirus Vaccine ◽  
Intestinal Immunity ◽  
Open Label ◽  
Seroprotection Rate ◽  
Global Policy ◽  
Viral Shedding ◽  
Viral Excretion ◽  
Open Label Phase

Abstract Background Understanding immunogenicity and safety of monovalent type 2 oral poliovirus vaccine (mOPV2) in inactivated poliovirus vaccine (IPV)–immunized children is of major importance in informing global policy to control circulating vaccine-derived poliovirus outbreaks. Methods In this open-label, phase 4 study (NCT02582255) in 100 IPV-vaccinated Lithuanian 1–5-year-olds, we measured humoral and intestinal type 2 polio neutralizing antibodies before and 28 days after 1 or 2 mOPV2 doses given 28 days apart and measured stool viral shedding after each dose. Parents recorded solicited adverse events (AEs) for 7 days after each dose and unsolicited AEs for 6 weeks after vaccination. Results After 1 mOPV2 challenge, the type 2 seroprotection rate increased from 98% to 100%. Approximately 28 days after mOPV2 challenge 34 of 68 children (50%; 95% confidence interval, 38%–62%) were shedding virus; 9 of 37 (24%; 12%–41%) were shedding 28 days after a second challenge. Before challenge, type 2 intestinal immunity was undetectable in IPV-primed children, but 28 of 87 (32%) had intestinal neutralizing titers ≥32 after 1 mOPV2 dose. No vaccine-related serious or severe AEs were reported. Conclusions High viral excretion after mOPV2 among exclusively IPV-vaccinated children was substantially lower after a subsequent dose, indicating induction of intestinal immunity against type 2 poliovirus.

scholarly journals Case of Poliomyelitis Caused by Significantly Diverged Derivative of the Poliovirus Type 3 Vaccine Sabin Strain Circulating in the Orphanage

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 970
Author(s):  
Ekaterina A. Korotkova ◽  
Maria A. Prostova ◽  
Anatoly P. Gmyl ◽  
Liubov I. Kozlovskaya ◽  
Tatiana P. Eremeeva ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Mucosal Immunity ◽  
Neutralizing Antibodies ◽  
Oral Poliovirus Vaccine ◽  
Paralytic Poliomyelitis ◽  
Epidemiological Investigation ◽  
Poliovirus Type ◽  
Complete Rejection ◽  
Type 3

Significantly divergent polioviruses (VDPV) derived from the oral poliovirus vaccine (OPV) from Sabin strains, like wild polioviruses, are capable of prolonged transmission and neuropathology. This is mainly shown for VDPV type 2. Here we describe a molecular-epidemiological investigation of a case of VDPV type 3 circulation leading to paralytic poliomyelitis in a child in an orphanage, where OPV has not been used. Samples of feces and blood serum from the patient and 52 contacts from the same orphanage were collected twice and investigated. The complete genome sequencing was performed for five polioviruses isolated from the patient and three contact children. The level of divergence of the genomes of the isolates corresponded to approximately 9–10 months of evolution. The presence of 61 common substitutions in all isolates indicated a common intermediate progenitor. The possibility of VDPV3 transmission from the excretor to susceptible recipients (unvaccinated against polio or vaccinated with inactivated poliovirus vaccine, IPV) with subsequent circulation in a closed children’s group was demonstrated. The study of the blood sera of orphanage residents at least twice vaccinated with IPV revealed the absence of neutralizing antibodies against at least two poliovirus serotypes in almost 20% of children. Therefore, a complete rejection of OPV vaccination can lead to a critical decrease in collective immunity level. The development of new poliovirus vaccines that create mucosal immunity for the adequate replacement of OPV from Sabin strains is necessary.

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