Genotypic stability of cold-adapted influenza virus vaccine in an efficacy clinical trial.
J Clin Microbiol
; 38(2): 839-45, 2000 Feb.
Article
in En
| MEDLINE
| ID: mdl-10655394
ABSTRACT
An investigational live influenza virus vaccine, FluMist, contains three cold-adapted H1N1, H3N2, and B influenza viruses. The vaccine viruses are 6/2 reassortants, in which the hemagglutinin (HA) and neuraminidase (NA) genes are derived from the circulating wild-type viruses and the remaining six genes are derived from the cold-adapted master donor strains. The six genes from the cold-adapted master donor strains ensure the attenuation, and the HA and NA genes from the wild-type viruses confer the ability to induce protective immunity against contemporary influenza strains. The genotypic stability of this vaccine was studied by employing clinical samples collected during an efficacy trial. Viruses present in the nasal and throat swab specimens and in supernatants after culturing the specimens were detected and subtyped by multiplex reverse transcriptase (RT)-PCR. Complete genotypes of these detected viruses were determined by a combination of RT-PCR and restriction fragment length polymorphism, multiplex RT-PCR and fluorescent single-strand conformation polymorphism, and nucleic acid sequencing analysis. The FluMist vaccine appeared to be genotypically stable after replication in the human host. All viruses detected during the 2-week postvaccination period were shed vaccine viruses and had maintained the 6/2 genotype.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Influenza A virus
/
Influenza B virus
/
Influenza Vaccines
/
Vaccination
Type of study:
Clinical_trials
Limits:
Humans
Language:
En
Journal:
J Clin Microbiol
Year:
2000
Document type:
Article
Affiliation country:
Estados Unidos