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[Poliovirus (Sabin strain) multiplication in human intestinal tract after oral polio vaccination]
N Morimoto1, S Abe, S Hashizume
1Japan Poliomyelitis Research Institute.
Insights
Poliovirus shedding in infants varied by type after primary vaccination, with type 3 showing increased intestinal multiplication. Antibody titers after secondary vaccination were comparable to those in 2-year-old Japanese infants.
Area of Science:
- Virology and Immunology
- Vaccine Research
Context:
- Poliovirus shedding dynamics in infants following vaccination are crucial for understanding transmission and vaccine efficacy.
- Assessing viral replication and host immune response provides insights into vaccine performance in a young population.
Purpose:
- To investigate the duration and characteristics of poliovirus shedding in infants after primary and secondary vaccinations.
- To evaluate the temperature-dependent plaque-forming ability of poliovirus isolates from infant feces.
- To determine neutralizing antibody titers in infants one year after secondary poliovirus vaccination.
Summary:
- Polioviruses were isolated from infant feces for extended periods post-primary vaccination (Type 1: 28 days, Type 2: 39 days, Type 3: 36 days).
- Type 3 poliovirus showed increased intestinal multiplication, while Type 1 and Type 2 showed diminished multiplication after primary vaccination.
- Plaque formation varied by poliovirus type and temperature; Type 1 isolates did not form plaques at 39.0°C or 39.5°C post-primary vaccination.
- Type 2 isolates showed increasing plaque formation at 39.5°C over time, while Type 3 isolates formed plaques readily at both tested temperatures.
- Secondary vaccination primarily yielded Type 1 isolates within 7 days.
- Neutralizing antibody titers one year post-secondary vaccination were Type 1: 320, Type 2: 110, and Type 3: 60, similar to 2-year-old infants in Japan.
Impact:
- This study elucidates differential poliovirus shedding patterns and temperature-dependent replication capacities in infants, informing vaccine development and public health strategies.
- The findings contribute to understanding the immunological response to poliovirus vaccines in infants and provide reference antibody titers for vaccine efficacy assessment.
Abstract:
Fecal specimens from a baby vaccine were collected every day from 1 to 51 days after primary vaccination and from 0 to 15 days after secondary vaccination. Polioviruses were isolated with GMK-2 cell line from 10% emulsion of the feces and titrated the virus contents in the emulsion of the feces. The isolated viruses were tested the reproductive capacity at 39.0 degrees C and 39.5 degrees C by the plaque method with primary cynomologous monkey kidney cells. Viruses were isolated from the feces during 28 days for type 1, 39 days for type 2 and 36 days for type 3 after primary vaccination, however, only type 1 viruses were isolated during 7 days after secondary vaccination. The multiplication of type 3 viruses in the intestine were increased after diminished the multiplication of type 1 and type 2. In plaque formation capacity at 39.0 degrees C and 39.5 degrees C, the isolates had shown to differ clearly among the types of poliovirus. After primary vaccination, type 1 isolates were not produced the plaques at 39.0 degrees C and 39.5 degrees C. Although type 2 isolates were not formed the plaques until the 14th day at 39.5 degrees C, the plaque formation capacity of the these isolates were increased gradually i.e.; on the 20th day (10(0.88) PFU/ml), the 26th day (10(2.00) PFU/ml) and the 39th day (10(2.63) PFU/ml) at 39.5 degrees C, and all of type 2 isolates tested were showed the plaque formation capacity (10(2.88 approximately 10(3.76) PFU/ml) at 39.0 degrees C. Type 3 isolates were formed plaques at 39.0 degrees C and 39.5 degrees C from the 7th day. After the secondary vaccination, type 1 isolates (7th day) was a little changed them. Neutralizing antibody titers were shown that type 1 was 320, type 2 was 110 and type 3 was 60 after 1 year of the second administration. These titers were closely similar the geometric mean titers of 2 year old babies in Japan.