Showing papers on "Viral Vaccine published in 1980"

Hepatitis B vaccine: demonstration of efficacy in a controlled clinical trial in a high-risk population in the United States.

Abstract: We assessed the efficacy of an inactivated hepatitis B vaccine in a placebo-controlled, randomized, double-blind trial in 1083 homosexual men known to be at high risk for hepatitis B virus infection. The vaccine was found to be safe and the incidence of side effects was low. Within two months, 77% of the vaccinated persons had high levels of antibody against the hepatitis B surface antigen. This rate increased to 96% after the booster dose and remained essentially unchanged for the duration of the trial. For the first 18 months of follow-up, hepatitis B or subclinical infection developed in only 1.4 to 3.4% of the vaccine recipients as compared with 18 to 27% of placebo recipients (P < 0.0001). The reduction of incidence in the vaccinees was as high as 92.3%; none of the vaccinees with a detectable immune response to the vaccine had clinical hepatitis B or asymptomatic antigenemia. A significant reduction of incidence was already seen within 75 days after randomization; this observation suggests that the vaccine may be efficacious even when given after exposure.

Approaches to Immunization of Infants and Young Children Against Gastroenteritis Due to Rotaviruses

Abstract: Recent studies have shown that in developed countries rotaviruses are the single most important etiologic agents of acute gastroenteritis that requires hospitalization of infants and young children. Although deaths from gastroenteritis are, in general, infrequent in the developed countries, an effective rotavirus vaccine would clearly be of benefit to reduce the heavy toll of morbidity from gastroenteritis due to rotavirus. In the developing countries the impact of diarrheal diseases is staggering. It was recently estimated that in Asia, Africa, and Latin-America during a one-year period there would be 3.5 billion cases of diarrhea and 5-10 million deaths associated with diarrhea; in addition, diarrhea was ranked first in freqency in the categories of disease and mortality. In the developing countries rotaviruses are known to cause diarrhea, but their relative role in this high mortality rate is not yet known. epidemiologic data indicate that development of an effective rotavirus vaccine would reduce morbidity, and they suggest that a vaccine would also reduce a portion of the mortality from diarrheal disease. The prospects and approaches for the development of an effective rotavirus vaccine are presented. The recent successful propagation of rotavirus type 2 in cell culture represents an important step in this regard. In addition, the antigenic relation between human and animal strains offers another possible approach. The need for a live attenuated vaccine is indicated by the prime role played by local intestinal immunity in resistance to rotavirus disease.

Reactivation of temperature-sensitive and non-temperature-sensitive infectious bovine rhinotracheitis vaccine virus with dexamethasone.

Abstract: Latent infections by a temperature-sensitive (ts) infectious bovine rhinotracheitis virus vaccines was produced as frequently as by non-ts vaccine virus. Thus virus could be reactivated in seven of eight ts vaccinates and six of eight non-ts vaccinates after dexamethasone treatment. Virus excretion could be detectable for 1 to 8 days at a level of 2 x 10(6) to 3 x 10(8) plaque-forming units per ml of nasal secretions. The reactivated virus was shown to be the same as the original virus used for vaccination by its inability to grow at the restrictive temperature (39 degrees C) as well as by its restriction endonuclease cleavage pattern.

Viral Vaccination Via the Mucosal Routes

Abstract: Viral vaccines have been successfully administered by the mucosal route for two decades now. However, only in the last 10 years have the concepts involved in mucosal immunocompetence been well characterized. It is apparent that the bronchus-associated lymphoid tissue, the gut-associated lymphoid tissue, and the immunocompetent cells present in ocular tissue, conjunctiva, nasopharynx, genital tract, and secretions of the mammary glands represent the components of the common mucosal immune system. The predominant immunologic activity in the external mucosal surfaces is associated with secretory IgA and T lymphocytes, with variable contributions from other immunoglobulins and macrophages. Evidence presented in this review suggests that immunization via the mucosal routes of the respiratory and gastrointestinal tracts is the most effective means of inducing effective immunity in the mucosal surfaces as well as in the systemic tissues. Available experience with mucosal immunization with poliovirus, rubella virus, measles virus, and adenovirus vaccines in humans and with other viral vaccines in animals is briefly reviewed. The foundations of the modern practice of immunization against infectious diseases were laid down by Jenner almost 200 years ago with the development of the vaccine against smallpox. The usefulness of immunoprophylaxis against other infections was clearly demonstrated by Pasteur in the later part of the nineteenth century with the development of vaccines against rabies, anthrax, and chicken cholera. The implementation of subsequent mass vaccination programs and the effective worldwide control of such infections as smallpox and poliomyelitis during the past three decades are fitting tributes to this early work on immunization. The development of inactivated (Salk) poliovaccine and the widespread successful use of diphtheria, pertussis, and tetanus vaccines in the early 1950s led to the belief that all infectious diseases could be prevented or cured simply by the administration of vaccine prepared against the identified microorganism. Over the years, the attitudes of the general public and the biomedical community toward vaccination programs in general have ranged from intense optimism to extreme skepti

Dengue-2 vaccine: preparation from a small-plaque virus clone.

Abstract: The S-1 clone of dengue type 2 virus was used for the preparation of a live-attenuated vaccine after passage in DBS-FRhL-2 cell culture. The vaccine virus had a relatively higher replicative capacity at superoptimal temperatures than its precursor virus, S-1, passaged in primary green monkey kidney cells (S-1 PGMK). There was also a tendency for the S-1 vaccine virus to exhibit leakiness at increased temperatures. Another in vitro marker, replication in monkey peripheral blood leukocytes, indicated less host restriction for the S-1 vaccine in comparative assays with S-1 PGMK virus. Mouse virulence appeared to remain stable on passage in DBS-FRhL-2 cells, whereas monkey immunogenicity decreased. Cautious trials of the dengue type 2 S-1 vaccine in humans are indicated.

Protection of laying hens against infectious bronchitis with inactivated emulsion vaccines.

Abstract: Commercially-reared laying chickens were challenged at 31 weeks of age with a virulent infectious bronchitis (IB) virus. They showed a sharp drop in egg production, despite having been vaccinated at four and eight weeks old with live attenuated IB vaccines to a recommended schedule. In contrast, similar birds that had been further immunised at point-of-lay with inactivated oil emulsion IB vaccine, or with a combined IB/Newcastle disease (ND) emulsion vaccine, showed no detectable fall in egg production after the same challenge. Unvaccinated susceptible specific pathogen-free birds challenged at the same time stopped laying almost completely. In the birds revaccinated with emulsion vaccine, measurement of haemagglutination inhibition antibody levels to IB showed their geometric mean titres to be raised from less than 5 log2 at the time of vaccination to over 10 log2 four weeks later. Their antibody levels did not rise further followining the IB challenge whereas in the birds that had not been revaccinated antibody rises to nearly 10 log2 were detected after the same challenge. For pullets vaccinated earlier with live IB vaccine, revaccination with inactivated IB or IB/ND oil emulsion vaccine at point-of-lay provides a safe and effective way of protecting their egg production against IB infection.

Dengue-2 Vaccine: Viremia and Immune Responses in Rhesus Monkeys

Abstract: Studies were undertaken in Indian rhesus monkeys (Macaca mulatta) to determine the safety, potency, immunogenicity, and mosquito infectivity of a small-plaque, temperature-sensitive variant of dengue type 2 (DEN-2) virus, a vaccine candidate. Fifteen monkeys were inoculated subcutaneously with the vaccine virus, ten receiving 10(3.1) plaque-forming units (PFU) and five receiving 10(4.5) PFU. After primary immunization, viremia was detected in only one monkey, a recipient of the higher dose of vaccine. The recovered virus had the same growth characteristics as the vaccine strain. Aedes aegypti mosquitoes did not become infected when they were allowed to feed on monkeys that received the lower dose of vaccine. As expected, the immunization produced no evidence of illness in any of the animals. A dose response to vaccine was detected; all five of the high-dose recipients developed neutralizing antibodies, whereas only five of ten low-dose recipients did so. In both groups, neutralizing antibody was often transient. Its presence at 30 days did not always correlate with protection from viremia in those animals challenged 4 to 6 months after vaccination with wild-type DEN-2 virus. However, immunized animals developed anamnestic antibody responses after challenge, and none demonstrated adverse effects to infection. Reimmunization of monkeys 4 months after primary immunization led to the production of low-titered but persistent neutralizing antibody which protected the animals from a wild-type virus challenge.

Stabilizer for liquid vaccines and liquid vaccine containing said stabilizer

Abstract: An improved stabilized liquid live viral vaccine contains a live virus, partially hydrolyzed gelatin, a monosaccharide or disaccharide, a cell culture medium, L-glutamic acid, L-arginine and sufficient physiologically acceptable acidic buffer to maintain the pH at from about 6.0 to about 6.5

Adjuvant activity of a novel metabolizable lipid emulsion with inactivated viral vaccines.

Abstract: Studies were conducted in mice, hamsters, sheep, and two species of nonhuman primates which demonstrate the adjuvant activity of a new metabolizable lipid emulsion with marginally immunogenic doses of Formalin-inactivated viral vaccines. The lipid base consists of highly refined peanut oil emulsified in aqueous vaccines with glycerol and lecithin. Hamsters and mice inoculated with lipid emulsion plus western or Venezuelan equine encephalitis vaccine were significantly more resistant than vaccinated controls to lethal homologous virus challenge. Sheep given one dose of lipid emulsion plus Rift Valley fever vaccine developed significantly higher antibody titers than control sheep receiving only vaccine. Cynomolgous monkeys inoculated with lipid emulsion plus Rift Valley fever vaccine developed 16-fold greater peak primary and 20-fold greater secondary antibody titers than those of vaccine controls. Similar lipid emulsion-Rift Valley fever studies in rhesus monkeys resulted in 37- and 300-fold increases in primary and secondary titers, respectively, compared with monkeys given vaccine alone. Neither the sequence of combining antigen with lipid nor the exact ratio of aqueous phase to lipid phase affected the survival of Venezuelan equine encephalitis-vaccinated mice challenged with homologous lethal virus. This lipid formulation has several advantages over other water-in-oil adjuvants for potential use in humans. The components are metabolizable or normal host constituents, it is easily emulsified with aqueous vaccines by gentle agitation, and it is relatively nonreactogenic in recipients.

Studies on canine parvovirus infections: development of an inactivated vaccine.

Abstract: parvoviruses isolated from the intestines of dogs that died of an enteric infection were propagated in various parasynchronized canine and feline cell cultures. Viral antigen could be visualized in infected cell cultures with the aid of fluorescein-labeled feline, as well as porcine, parvovirus antisera, and in an indirect test with sera from dogs that had recovered from a parvovirus infection. The virus hemagglutinated porcine RBC at 4 C and 25 C but not at 37 C. An inactivated canine parvovirus vaccine elicited an immune response, but no adverse reactions, when inoculated into dogs. Vaccinated dogs were immune and did not show any clinical signs when challenge exposed with virulent virus, whereas nonvaccinated, nonimmune dogs became clinically ill when inoculated with the same virus. Humoral hemagglutination-inhibiting parvovirus antibody values corresponded well with susceptibility and resistance to experimental inoculation of dogs with canine parvoviruses.

The immune response of chickens vaccinated against Newcastle disease with live Newcastle disease V4 vaccine.

Abstract: Vaccination of chickens with the commercial Newcastle Disease (ND) V4 vaccine at 21 days old or at 21 and 35 days old, stimulated satisfactory and persistent HI antibody levels. The vaccinated chickens were immune when challenged at 49 days old or 77 days old with the virulent strain of NDV administered intramuscularly, intranasally or by contact. Postmortem findings of the non-vaccinated and vaccinated chickens that died from the challenge were recorded.

Large-scale purification of Japanese encephalitis virus from infected mouse brain for preparation of vaccine.

Abstract: Large volumes of Japanese encephalitis (JE) virus propagated in mouse brain can be easily purified by polyethylene glycol 6,000. By using the polyethylene glycol precipitation method, mouse hemoglobin was almost all separated from the viral suspension, and consequently the total amount of nonviral protein in the viral suspension decreased. The recovery of infectivity was about 100%. The removal of residual polyethylene glycol in the viral suspension was possible without difficulty by means of ethanol precipitation. This method is recommended as an initial step in large-scale purification of Japanese encephalitis virus propagated in mouse brain because it is simple, rapid, and inexpensive.

Inactivated Mouse Cytomegalovirus Vaccine: Preparation, Immunogenicity, and Protective Effect

Abstract: Mouse cytomegalovirus (CMV) was rapidly and completely inactivated at 37 C by formalin diluted 1:4,000. Of 18 mice that received two doses of inactivated mouse CMV, 16 survived challenge with 250% lethal doses of mouse CMV; one of 11 mice receiving two doses of a control preparation survived the challenge (P < 0.005). After challenge with live virus, recognizable morbidity occurred in only four of 16 recipients of inactivated mouse CMV, but the virus was recovered from the salivary glands of 15 animals. Mice with reciprocal prechallenge titers of neutralizing antibody of < 4 demonstrated significantly higher morbidity and mortality than mice with higher antibody titers. Administration of inactivated mouse CMV did not depress responsiveness of spleen cells to phytohemagglutinin. Most mice immunized with inactivated virus developed only mild or subclinical infections after challenge with lethal doses of mouse CMV.

Use of captive-bred monkeys for vaccine production.

Abstract: Cynomolgus monkeys (Macaca fasicularis) were bred in captivity for the production and control of inactivated poliomyelitis vaccine. Compared to imported wild-caught animals the captive-bred monkeys contracted fewer virus infections, as evidenced by results of serological examination, and yielded remarkably clean cell cultures. These cultures could be grown in series and appear very suitable for the production of viral vaccines.

Antibody Response to Influenza A/New Jersey and A/Victoria Virus Vaccines in 1976 and Subsequent Antibody Levels after Influenza A Epidemics, 1977–1979

Abstract: Antibody levels before and after vaccination were studied among schoolchildren and young adults given commercial A/New Jersey/76 (HswN1), A/Victoria/75 (H3N2), and B/Hong Kong/72 vaccines in the fall of 1976. Children responded better to a single dose of the A/New Jersey subvirion vaccine than had previously been observed, particularly to a new subvirion vaccine. Hemagglutination-inhibiting antibody titers decreased during the first six months after vaccination but appeared stable thereafter. Persistence seemed to depend on the antigenic mass in the first dose, since persons given one or two doses of the most potent whole-virus vaccine had by far the highest levels of antibody to A/New Jersey virus after 2 1/2 years, higher than for those given two doses of any of the other vaccines. Natural infection with A/USSR (H1N1) influenza virus boostered the titers of antibody to A/New Jersey virus, particularly in children. Persons given a bivalent subvirion vaccine had the best response to A/Victoria antigen. Subvirion vaccines induced complement-fixing antibodies in half of the children.

Humoral and cellular immune response to varicella-zoster virus in children inoculated with live attenuated varicella vaccine.

Abstract: Twenty-seven hospitalized children without a history of varicella were vaccinated with 500 plaque forming units of live attenuated varicella vaccine (Oka strain) and followed for four to five weeks at weekly intervals for the development of virus-specific cell-mediated immunity (CMI) and neutralizing (NT) antibody activity. These children had suffered from heterogeneous underlying diseases, such as acute leukemia, lymphoma, the nephrotic syndrome, and other chronic illnesses and were in various immunological states. Development of specific CMI, detected by lymphocyte transformation (LTF), was observed in 23 of the 27 children. The appearance of LTF activity in immunologically handicapped patients was delayed and/or rather suppressed compared with that of immunologically normal patients. An antibody response was detected in 26 of the 27 children. All of the vaccinated patients were protected effectively against a subsequent outbreak of varicella in the ward.

[Concentrated purified vaccine against tick-borne encephalitis prepared by means of zonal ultracentrifugation. Development of the preparation].

Abstract: A concentrated and purified (lyophilized) preparation with a high immunological activity was obtained from formalin-inactivated tissue culture suspensions of tick-borne encephalitis (TBE) virus. Its high immunogenicity was demonstrated in mouse protection tests against fatal challenge with TBE and in the studies of antibody production in monkeys of two species. The preparation was shown to contain no infectious TBE virus, to be safe for small laboratory animals and monkeys. Trials of the preparation in 19 volunteers demonstrated it to be well tolerated and to induce virus-neutralizing antibody production in man. It also sensitized lymphoid cells when inoculated subcutaneously with Al2O3. These experimental materials indicate the possibility of developing a highly potent vaccine against tick-borne encephalitis by concentration and purification of TBE particle suspensions.

Prospects for new viral vaccines

Abstract: Animal virology has made outstanding contributions to preventive medicine by the development of vaccines for the control of infectious disease in man and animals. Cost-benefit analysis indicates substantial savings in health care costs from the control of diseases such as smallpox, poliomyelitis, yellow fever and measles. Areas for further development include vaccines for influenza (living, attenuated virus), the herpes group (varicella: cytomegalovirus), respiratory syncytial virus, rotavirus and hepatitis A, B, and non A/non B. The general options for vaccine formulation are discussed with particular emphasis on approaches with the use of viral genetics to `tailor make' vaccine viruses with defined growth potential in laboratory systems, low pathogenicity, and defined antigens. Current progress with the development of an inactivated hepatitis B vaccine is reviewed as a case study in vaccine development. The impact of recent experiments in cloning hepatitis B virus DNA in E. coli on the production of a purified viral polypeptide vaccine is assessed.

Quantitation of cell DNA in the evaluation of heteroploid cells as substrate for the preparation of killed viral vaccines.

Abstract: To evaluate the risk of using heteroploid cell lines as substrates for viral vaccine production, the presence of cell DNA in poliovirus suspensions was examined. The time course of [3H]-thy

[Requirements of rabbit-adapted swine fever vaccine]

Abstract: Studies were conducted into the demands made on both harmlessness and effectiveness of SUVAC, a swine fever vaccine prepared from strain "C", a rabbit-adapted Chinese virus strain. The following findings were obtained: --The vaccine strain was attenuated to an extent by which it could be used without serum. --The vaccine was harmless even with immunodepressor action. Its immunogenicity was good, and live weight growth of the animals was not impaired. --The vaccine was harmless to the foetuses. --Very little virus was excreted by immunised pigs. --Vaccine attenuation was of high stability, and virulence was not even increased after six passages in pigs. --Between 50 and 100 immunising units were contained in one vaccine dose, and piglets immunised at the age of six weeks were protected after three months against an experimental infectino which was fatal to susceptible pigs. --Virus inoculated into PK 15-cell line proved negative in the first passage in response to immunofluorescence testing.

Active immunizations for adults.

Abstract: Lack of effective antiviral drugs has led to dependence on vaccines for control of many viral diseases. These diseases are primarily "childhood diseases," so immunization activities have largely been directed toward children. Notable exceptions to this emphasis on children are influenza immunizations. Even with effective viral vaccines, significant efforts to im­ munize children, and generous financial support to purchase vaccines, it is becoming evident that a portion of the adult population remains susceptible to one or more of these common childhood diseases. These adults are "victims" of one or more of the following circumstances: (a) the widespread use of vaccines creates a herd immunity that reduces the usual exposure to these viruses; (b) not all persons are immunized in childhood; or (c) some persons receive ineffective or mishandled vaccines (vaccine failure). The bottom line is that an increasing proportion of adults could greatly benefit from "childhood" vaccinations. The situation is somewhat complicated by the relative lack of knowledge of these vaccines among nonpediatricians, as well as indications that these vaccines are less antigenic (1) and at times more reactive (2) in adults. Adults are the primary target for influenza and rabies vaccines, although children frequently receive the latter. Influenza immunization creates con­ fusion, frustration, and/or fright because of the many influenza strains that have been isolated, the phenomena of antigen drift and shift, the unpredicta­ bility of influenza outbreaks, the varying manufacturing processes, the cre­ ation of "priority" categories to receive the vaccines, frequent reactions, and the unexplained relation between "Swine" influenza vaccine and the Guil­ lain-Barre syndrome. Decisions on administration of rabies vaccination may be delayed and the vaccine may cause serious side effects. Several viral vaccines are required only by the traveler, and at times are unavailable at the family practitioner's or internist's office. Finally, in the