Showing papers on "Viral Vaccine published in 1971"

Antibody Response in Serum and Nasopharynx after Naturally Acquired and Vaccine-Induced Infection with Rubella Virus

Abstract: Antibody response to rubella virus was studied in serum and nasopharyngeal secretions after natural infection, intranasal inoculation with RA-27/3 rubella vaccine and subcutaneous administration of HPV-77 DK/12 rubella-virus vaccine. Serum antibody responses after natural infection or immunization were similar and characterized by the sequential appearance of γM, γG and occasionally γA antibody. Secretory antibody response after natural infection or intranasal immunization was characterized by regular appearance of nasopharyngeal γntibody. Little or no nasopharyngeal response was observed after subcutaneous immunization with HPV-77 vaccine. These data may explain the poor nasopharyngeal immunity to reinfection with wild rubella virus in subjects previously immunized with parenterally administered rubella-virus vaccine.

Large-scale purification of rubella virus and preparation of an experimental split rubella virus vaccine.

Abstract: Large-scale purification of rubella virus from tissue culture fluid and preparation of an experimental rubella subunit vaccine are described. The virus, purified isopycnically in sucrose gradients, was Tween 80-ether treated, and the product was filtered sterile. The vaccines were of two types, formalinized and nonformalinized. They were not infectious, had only a slight pyrogenicity, and caused no harmful symptoms in animals. The immune response in guinea pigs was better when the nonformalinized vaccine was used and the dosage was 2,500 hemagglutinating units per injection (0.5 ml).

Vaccination of adults with Wistar RA 27/3 rubella vaccine.

Abstract: Thirty-three adults were vaccinated subcutaneously with Wistar RA. 27/3 (live attenuated) rubella vaccine at the Wellcome Research Laboratories, Beckenham. All subjects with pre-vaccination haemagglutinating-inhibiting antibody titres of 1/20 or less and three of seven subjects with pre-vaccination titres of 1/40 showed at least fourfold rises of titre. Reactions encountered were mild and of short duration.

Correlated Studies of a Recombinant Influenza-Virus Vaccine. II. Definition of Antigenicity in Experimental Animals

Abstract: The present experiments were designed to assess the immunogenic properties of an inactivated influenza-virus vaccine made from a recombinant virus (X-31) that possesses the surface antigens of Aichi virus and the growth capacity in eggs of A0/PR8 virus. Antibody response in mice and rabbits was tested by assay for titers of hemagglutination inhibition, plaque inhibition, plaque-size reduction, and neuraminidase inhibition following immunization with graded doses of the recombinant vaccine and a standard Aichi virus vaccine of equivalent antigenic content, as determined by the chick-cell-agglutination test. The X-31 vaccine was slightly more effective in eliciting antibody to hemagglutinin in both rabbits and mice and was also more effective than Aichi vaccine in increasing the resistance of mice to the initiation of infection with Aichi virus. Similar titers of antibody to neuraminidase were elicited by the two vaccines, and both were more potent in stimulating antibody to hemagglutinin than to neuraminidase. The results indicate that the recombinant vaccine was at least as effective as a standard vaccine in its immunogenic properties. In addition, the results of these experiments raise questions regarding the accuracy of the chick-cell-agglutination test as a method for assaying immunogenic potency.

Inactivated Eastern Equine Encephalomyelitis Vaccines Prepared in Monolayer and Concentrated Suspension Chick Embryo Cultures

Abstract: Eastern equine encephalomyelitis vaccines were prepared with virus propagated in stationary monolayer cultures and in concentrated suspension cultures of primary chick embryo cells. Virus pools for vaccine preparation were inactivated by three different methods: 0.05% formalin, 41 C heat, and 0.16% beta-propiolactone. Heat-and beta-propiolactone-inactivated vaccines maintained high hemagglutinating titers in the fluid state for at least 10 months, whereas formalin-inactivated vaccines lost their hemagglutinating activity within a few hours after treatment. The hemagglutinin of beta-propiolactone-inactivated virus particles was more dense than the hemagglutinin of the parent virus particles, as determined by sucrose density gradient centrifugation. The increase in density may be due to the degradation or removal of the lipid from the virus envelope. When administered to guinea pigs, all three vaccines stimulated hemagglutination-inhibiting, complement-fixing, and neutralizing antibodies and afforded protection against a live virus challenge. Test results showed that vaccines prepared with virus propagated in concentrated suspension cultures were more immunogenic and stimulated greater serologic responses in guinea pigs than vaccines derived from monolayer-propagated virus. The beta-propiolactone-inactivated vaccine was most protective, the heat-inactivated (41 C) vaccine next, and the formalin-inactivated vaccine least potent.

Absence of an All‐or‐None Type of Complement Requirement in Early Neutralizing Antibody against Western Equine Encephalitis Virus

Abstract: Rabbits were immunized by 2 weekly intravenous inoculations of beta-propiolactone-inactivated Western equine encephalitis virus vaccine followed 1 week later by a subcutaneous inoculation of live virus, and complement requirements of early and late neutralizing antibodies were compared. There was no difference between these antibodies, both showing about a 4-fold enhancement of the virus-neutralizing activity in the presence of complement. This was also the case when guinea pigs were given the vaccine by the intraperitoneal route. It is unlikely that previous exposure of the animals to an antigenically related virus caused a booster effect upon the antibody development, because the rabbit antibody could not even neutralize the closely related Sindbis virus either in the presence or in the absence of complement. The reason for the existence of 2 different types of primary responses with respect to the complement requirement of early neutralizing antibody is discussed.

Trials of intranasally administered rubella vaccine

Abstract: No evidence of vaccine virus transmission was found in two studies where Wistar RA 27/3 rubella vaccine was administered intranasally. Vaccine was immunogenic in all of 23 vaccinated children in one study, while in the other only 5 of the 11 vaccinees developed antibody. The reduced seroconversion rate in the latter study appears to have been caused by one or a combination of factors, including the vaccination technique, the presence of infective nasal conditions in vaccinees and the titre of vaccine used.

Inactivated Eastern Equine Encephalomyelitis Vaccine Propagated in Rolling-Bottle Cultures of Chick Embryo Cells

Abstract: A method was developed for the production of Eastern equine encephalomyelitis vaccine from virus grown in rolling-bottle cultures (840 cm(2) growth area) of chick embryo cells. The PE-6 strain of virus was propagated in chick embryo cell roller cultures maintained on serum-free medium 199 containing 0.25% human serum albumin and antibiotics (MM). A multiplicity of inoculum of 0.005 yielded acceptable titers of virus at a convenient harvest time of 18 to 24 hr and reduced the carry-over of extraneous material from the virus seed. Growth studies in which 100, 200, or 300 ml of MM was used showed that use of 300 ml of MM offered two advantages: (i) cytopathic effects were less at the 18- to 24-hr harvest time, thereby decreasing cellular material in the final product, and (ii) total virus yield was not substantially reduced, thus permitting large-scale production of virus for further processing. Studies on formalin inactivation at 37 C indicated that the virus was inactivated by 0.05% formalin within 12 to 16 hr and with 0.1% formalin within 6 to 8 hr. Antigen extinction tests in hamsters revealed excellent potency (e.g., median-effective-dose values of 0.069 to 0.012 ml) for both fluid and freeze-dried products. The advantages of the roller-bottle technique in vaccine production are discussed.

Field trials of an inactivated oil-adjuvant vaccine against louping-ill (Arbovirus group B)

Abstract: A single dose of inactivated louping-ill oil-adjuvant vaccine elicited a sero-logically detectable immune response in sheep lasting for at least 1 year. These sheep when exposed to a natural focus of louping-ill virus were completely protected from clinical disease and 1 year after vaccination were able to pass on a substantial maternal immunity to their lambs.Twenty-nine per cent of unvaccinated sheep, exposed at the same time, died from clinical louping-ill; half of the survivors showed positive sero-conversion and became immune, while the other half remained susceptible. The incidence of fatal encephalomyelitis in sheep which were known to have circulated virus exceeded 50% in 2 out of 3 trials conducted simultaneously in different locations in Scotland in 1969.

Transmission of rubella vaccine virus from vaccinees to contacts.

Abstract: The report presents evidence of the transmission of hpv-77 derived rubella vaccine virus from vaccinees to two susceptible contacts. The first instance of transmission was to a child who served as a transmission control on a "closed" study ward, and the second was to an antibody-negative mother in an "open" family study. Neither of these persons had any clinical evidence of rubella. Both had significant increases in rubella hemagglutination inhibiting (hai) antibody titers, but detectable complement fixing (cf) antibodies did not develop in either. With the kind of antigen used in our rubella cf test, this pattern of serologic response is characteristic of, but not diagnostic of, infection with the rubella vaccine virus. The serological evidence which was compatible with rubella vaccine virus infection, the complete absence of serologic or clinical evidence of "wild" rubella virus infections among the other four rubella susceptible transmission control children and the security precautions employed to ensure isolation on the "closed" ward, make "wild" rubella virus infection extremely unlikely. The evidence for rubella vaccine virus infection in the other susceptible contact is not as conclusive, because "wild" rubella virus infection is difficult to rule out in any person living in an "open" family situation. Nevertheless the need for more data is emphasized by the virtual certainty that rubella vaccine virus transmission did occur in the subject on the isolation ward, plus the high probability that the infection observed in the family group setting also represented transmission of rubella vaccine virus. Such data can only come from close surveillance of recipients of live rubella virus vaccines and their contacts in the future.

Persistence of antibody after subcutaneous vaccination with Wistar RA 27/3 rubella vaccine

Abstract: After subcutaneous vaccination of rubella sero-negative children with Wistar RA 27/3 rubella vaccine, haemagglutination-inhibiting antibody titres were compared in sera taken 46 days and 2 years after vaccination. Antibody titres were well maintained in the absence of any known exposure to natural infection.

Study of an attenuated strain of feline infectious enteritis (panleucopaenia) virus. I. Spread of vaccine virus from cats affected with feline respiratory disease.

Abstract: In the course of developing a living attenuated feline infectious enteritis (panleucopaenia) vaccine, it was found that respiratory disease-infected cats newly inoculated with this vaccine spread vaccine virus to respiratory disease-infected in-contact controls. These in-contact controls were able to infect other cats with which they were placed in contact so that after five natural transmissions in this way and two oral administrations and subsequent re-isolations, reversion to virulence became evident. It is clear that before general release of a new living feline infectious enteritis vaccine, there must be satisfactory evidence that concurrent infection will not affect the safety of the modified antigen. In cats infected with feline infectious enteritis there appears to be a short period, coinciding with the onset of leucopaenia, during which they are highly infectious. It seems possible that some infected animals may become immune carriers because virus has been recovered from the small intestine of two of four cats with significant antibody titres 22-24 days after exposure to infection.

Live trachoma vaccine and topical therapy.

Abstract: It was stated (Scott, I964) that a live trachoma vaccine had no clear-cut effect in cases of severe trachoma although there were encouraging results in patients with mild trachoma and in a volunteer. This paper, which describes a further study supported by statistical analysis carried out on 553 children over a period of 5 years, confirms that no clear-cut benefit was obtained from the use of a live trachoma vaccine in cases of severe trachoma.