Influenza Virus and Vaccines

Study Notes

Highly infectious acute disease
First influenza A strain was isolated in 1933
In 1946, different strains appeared
Variant A2 strain was responsible for the pandemic of 1957
Influenza virus for vaccine manufacture is prepared in embryonated hen's eggs
Type A and type B components are standardized by hemagglutination titration before dilution and blending into a vaccine
Living attenuated virus is sprayed into the nose in USSR
Isolated hemagglutinin of the virus is immunogenic and does not give rise to febrile and toxic reactions
ϒ-globulin may help to neutralize the viraemia when administered in the early stages before the virus has infected nerve cells

Preventable disease
Killed vaccine is produced by monkey kidney cell cultures
Immunization: 2 doses given by IM at an interval of 4-6 weeks, followed by a similar dose given 9-12 months later, and a fourth dose 5-6 years later
Killed vaccine can be incorporated with Diphtheria, tetanus, and pertussis prophylactics (quadruple vaccine)
Live vaccine is made by infecting monkey kidney or human embryo lung fibroblast cell cultures with attenuated virus strains
Vaccine is given orally as monovalent virus in the order of Type 1, followed by Type 3, and finally Type 2, with an interval of 6 weeks between each dose

ϒ-globulin Prepared from recently vaccinated donors protects unvaccinated household contacts of smallpox or persons last vaccinated many years previously
Control vaccinia and vaccinial infections of the eye can be controlled by ϒ-globulin (500 mg - 2.0 g) depending on patient age

Acute sporadically or in epidemics, caused by a virus spread by ingesting food or water contaminated with feces
Epidemics of infectious hepatitis (viral hepatitis A) have been successfully controlled by an injection of ϒ globulin prepared from normal adult serum
Prophylactic ϒ globulin is recommended to all contacts of infectious hepatitis, especially pregnant and post-menopausal women, as early as possible after exposure, and confers protection even if given as late as 6 days before the onset of symptoms

Highly infectious acute disease caused by measles virus
The disease can be attenuated or completely prevented by ϒ – globulin prepared from pooled adult serum
Killed vaccine prepared by formalin treatment of virus grown in either monkey kidney or dog kidney cells