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 ◽  
...  

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.

Author(s):  
Nilsa de Deus ◽  
Igor Paulo Ubisse Capitine ◽  
Adilson Fernando Loforte Bauhofer ◽  
Selma Marques ◽  
Marta Cassocera ◽  
...  

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.


Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 970
Author(s):  
Ekaterina A. Korotkova ◽  
Maria A. Prostova ◽  
Anatoly P. Gmyl ◽  
Liubov I. Kozlovskaya ◽  
Tatiana P. Eremeeva ◽  
...  

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.


PEDIATRICS ◽  
1977 ◽  
Vol 60 (1) ◽  
pp. 80-82
Author(s):  
Richard D. Krugman ◽  
George E. Hardy ◽  
Clyde Sellers ◽  
Paul D. Parkman ◽  
John J. Witte ◽  
...  

Five years after primary infant immunization with trivalent oral poliovirus vaccine, employing either a three-dose primary series as recommended by the U.S. Public Health Service Advisory Committee on Immunization Practices (ACIP) or a four-dose series as recommended by the Committee on Infectious Diseases of the American Academy of Pediatrics, 115 children were serologically tested for persistence of neutralizing antibodies by the microneutralization test. Of the 57 individuals immunized according to the ACIP recommendation, antibody persistence was demonstrated in 92% for type 1 poliovirus, 98% for type 2, and 84% for type 3. Of those 58 individuals originally receiving a four-dose primary infant immunization series, the persistence of antibody was 98% to type 1, 98% to type 2, and 87% to type 3. Twenty-one of 24 negative sera showed neutralizing ability when tested by a more sensitive plaque reduction test. Thus, individuals completing either immunization schedule demonstrated satisfactory persistence of neutralizing antibody to all three poliovirus types over a five-year period.


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