Showing papers on "Vaccination published in 1982"

Directly transmitted infections diseases: control by vaccination

Abstract: Mathematical models for the dynamics of directly transmitted viral and bacterial infections are guides to the understanding of observed patterns in the age specific incidence of some common childhood diseases of humans, before and after the advent of vaccination programs. For those infections that show recurrent epidemic behavior, the interepidemic period can be related to parameters characterizing the infection (such as latent and infectious periods and the average age of first infection); this relation agrees with the data of a variety of childhood diseases. Criteria for the eradication of a disease are given, in terms of the proportion of the population to be vaccinated and the age-specific vaccination schedule. These criteria are compared with a detailed analysis of the vaccination programs against measles and whooping cough in Britain, and estimates are made of the levels of protection that would be needed to eradicate these diseases.

The prevention of hepatitis B with vaccine. Report of the centers for disease control multi-center efficacy trial among homosexual men.

Abstract: A randomized, double-blind, vaccine/placebo trial of the Merck 20-micrograms hepatitis B virus (HBV) vaccine was done among 1402 homosexual men attending venereal disease clinics in five American cities. Vaccination was followed by only minimal side effects. Two doses of vaccine induced antibody in 80% of vaccine recipients. A booster dose 6 months after the first dose induced antibody in 85% of recipients and markedly increased the proportion of recipients who produced high antibody titers. The incidence of HBV events was markedly less in the vaccine recipients compared to that in the placebo recipients (p = 0.0004). Between month 3 and 15 after the first dose, 56 more significant HBV events (hepatitis, or hepatitis B surface antigen positive, or both) occurred in the placebo group while only 11 occurred in the vaccine group. Ten of the 11 HBV events in the vaccine recipients occurred in hypo- or nonresponders to the vaccine. This vaccine appears to be safe, immunogenic, and efficacious in preventing infection with hepatitis B virus.

Indications for use of hepatitis B vaccine, based on cost-effectiveness analysis.

Abstract: To formulate indications for the use of hepatitis B vaccine, we examined the cost effectiveness of three strategies: vaccinating everyone; screening everyone and vaccinating those without evidence of immunity; and neither vaccinating nor screening, but passively immunizing those with known exposure. Estimates of the hepatitis attack rate, prevalence of immunity, and frequency of known exposure were made for three representative populations: homosexual men, surgical residents, and the general population of the United States. Screening followed by vaccination of homosexual men and vaccination without prior screening of surgical residents would result in savings of medical costs. Neither screening nor vaccination is the lowest-cost strategy for the general population. Vaccination of susceptible persons will save medical costs for populations with annual attack rates above 5 per cent. Vaccination may be considered cost effective (or cost saving when indirect costs are included) for populations with attack rates as low as 1 to 2 per cent.

Guillain-Barré syndrome in the United States, 1979-1980 and 1980-1981. Lack of an association with influenza vaccination.

Abstract: An ongoing surveillance program was intensified during the 1979-1980 and the 1980-1981 influenza seasons to determine whether an increased risk of acquiring Guillain-Barre syndrome (GBS) within eight weeks after influenza vaccination existed for adults in the United States who received influenza vaccine, when compared with adults who had not been vaccinated recently. Five hundred twenty-eight cases of GBS with onset between Sept 1 and March 31, including seven following recent vaccination, were reported by participating neurologists in 1979-1980; 459 cases, including 12 following recent vaccination, were reported in 1980-1981. The relative risk of acquiring GBS following influenza vaccination—0.6 in 1979-1980 and 1.4 in 1980-1981—was not significantly different from 1.0 in either season. These results suggest that there was no increased risk of acquiring GBS associated with the influenza vaccines administered during these seasons and that the causative "trigger agent" in the A/New Jersey (swine) influenza vaccine administered in 1976 has not been present in subsequent influenza vaccine preparations. ( JAMA 1982;248:698-700)

A successful eradication campaign. Global eradication of smallpox.

Abstract: Smallpox was the first important disease to be eradicated; it was the success of the Smallpox Eradication Programme that inspired this conference. Several biological reasons favored the eradication of smallpox, the most important of which were probably that recurrent infectivity did not occur, that there was no animal reservoir, and that an effective stable vaccine was available. The importance of smallpox as a disease that travelers might import into countries free of smallpox provided a powerful stimulus for its global eradication. This paper highlights some of the problems associated with the eradication of smallpox in two countries where eradication was difficult, India and Ethiopia, and the measures adopted to overcome the problems. The paper also stresses the importance of the development of methods for the certification of smallpox eradication from countries, from regions, and finally from the whole world. It is noted that close links between field work and research were important throughout the eradication campaign.

Administration of a highly attenuated, live respiratory syncytial virus vaccine to adults and children.

Abstract: A highly attenuated respiratory syncytial virus (RSV) experimental vaccine, RSV ts-2, was sequentially evaluated in adults, seropositive children, and finally, fully susceptible seronegative children. The vaccine was administered intranasally in doses ranging from 10(5.2) to 10(6.3) PFU/ml. In both adults and children, the vaccine proved to be poorly infectious. Although poor infectivity would not have been predicted from tissue culture studies of RSV ts-2 growth, the human experience closely parallels the experience in a series of animal models, including the chimpanzee. The poor infectivity of this RSV vaccine virus preparation suggests that the postulated defect in the RSV ts-2 fusion protein may be important in determining in vivo infectivity of RSV.

Whooping cough and whooping cough vaccine: the risks and benefits debate

Abstract: There has been extensive debate in Great Britain regarding the risks and benefits of routine infant immunization against whooping cough. As a result of highly publicized cases of brain damage alleged to have been caused by the vaccine immunization acceptance rates have dropped dramatically and epidemics of the disease have recurred. On the basis of a review of the current state of knowledge on whooping cough the vaccine and vaccine safety the authors conclude that the dangers of the disease outweigh any known hazards of the vaccine. Although whooping cough is less important a cause of death and disability at present it remains a potentially lethal disease that should be controlled. The safety of the vaccine is an especially critical question however since it is being advocated for use on a mass scale in previously healthy children. The results of studies such as the National Childhood Encephalopathy Study suggest DPT vaccination is associated with a greater frequency of acute neurological illnesses than would be expected by chance. On the other hand most cases of such complications were not time-associated with DPT vaccination and may have resulted from the less purified vaccines used in the past. The most critical element in decision making is the readiness of parents and doctors to accept the fact that active preventive measures such as pertussis immunization sometimes carry unavoidable risks that have to be weighed against the risk of nonintervention.

Pneumococcal Vaccine: Clinical Efficacy and Effectiveness

Abstract: Streptococcus pneumoniae causes substantial morbidity and mortality. Incidence and severity are increased among populations with some chronic diseases. The currently available polyvalent polysaccharide vaccine induces antibody production among immunologically competent recipients against the 14 serotypes responsible for 80% of pneumococcal bacteremia in the efficacious in clinical trials with healthy young men in epidemic conditions and in patient with sickle cell anemia. Similar trials in two other high-risk populations had inconclusive results. Decisions on vaccine use now largely rest on indirect evidence of efficacy derived from knowledge of disease incidence, severity, and antibody response to vaccination among patient groups. Findings of a literature review suggest vaccinating high-risk patients immunologically competent to produce homotypic antibodies in response to vaccination with polysaccharide antigen, while continuing investigation of disease incidence, severity, serotype distribution, and immunologic response among high-risk groups and postmarketing surveillance efforts among all vaccinated patients.

Cold-Adapted Recombinant Influenza A Virus Vaccines in Seronegative Young Children

Abstract: Two live, attenuated, intranasally administered influenza virus vaccines were evaluated in 21 seronegative young children at Vanderbilt Children's Hospital (Nashville, Tennessee). The vaccines were derivatives of a cold-adapted master strain, influenza A/Ann Arbor/6/60 virus, containing the hemagglutinin and neuraminidase of one of two contemporary strains, influenza A/Hong Kong/123/77 (H1N1) or A/Alaska/6/77 (H3N2) virus. Both vaccine strains replicated in seronegative young children without evidence of genetic instability. In addition, both vaccine strains caused no identifiable clinical reactions, were not transmitted to other seronegative children, and gave long-lasting immunity. In a subsequent naturally occurring epidemic of influenza A/Bangkok (H3N2) virus, children previously vaccinated with the related strain, influenza A/Alaska (H3N2) virus, were significantly protected as judged by serologic evidence of reinfection.

Measles in England and Wales—II: The Impact of the Measles Vaccination Programme on the Distribution of Immunity in the Population

Abstract: Measles notification and vaccination data for England and Wales are analysed to reveal trends in age-specific incidence and immunity levels in successive cohorts born since 1950. A method for cumulating infection and vaccination experience is described in detail. The analysis reveals that there was a trend towards lower incidence rates of measles, and towards younger average age of cases, for the 10 years prior to commencement of the national immunization programme in 1968. Since the immunization programme began, there has been a dramatic and complicated shift in the age pattern of measles immunity in the population, such that some young age groups are now better protected, but some older age groups less well protected, than they were before the programme. These trends are discussed with critical attention to the possibility that they may reflect biases in the available data. It is concluded that the number of susceptibles over 10 years of age is increasing, and that this could have appreciable public health implications in the years to come. It appears that the total number of individuals susceptible to measles has remained relatively constant, between 4 and 4.5 million, before and after the immunization programme. Though consistent with basic theory, this maintenance of constant overall number of susceptibles has not been demonstrated before. Because the implications of these analyses are important for the strategy of measles control, it is important that appropriate serological surveys be carried out in order to assess the validity of the findings.

Hepatitis B Vaccine Administered to Chronic Carriers of Hepatitis B Surface Antigen

Abstract: We administered up to 6 monthly doses of hepatitis B vaccine to 16 chronic carriers of hepatitis B surface antigen (HBsAg) in an attempt to eliminate the antigen. The HBsAg in this vaccine differs from native antigen. No patients had elimination of HBsAg, but one of 10 no longer carried hepatitis B e antigen (HBeAg), Of 13 patients without preexisting antibody to HBsAg (anti-HBs), none acquired the antibody; two of three patients with preexisting heterotypic anti-HBs had transient, low-level increases in anti-HBs titers. Serum alanine aminotransaminase (ALT) levels fell in eight patients, remained unchanged in six, and increased transiently in two. Decreased ALT and HBeAg clearance, however, did not seem to be related to vaccination, and the transient ALT elevations appeared to represent sporadic, acute non-A, non-B hepatitis. No adverse effects other than sore arm and joint pain were seen. Immunization of chronic HBsAg carriers with hepatitis B vaccine, although ineffective in eliminating HBsAg, appeared to be safe. Such safety, if confirmed, would simplify the design of hepatitis B vaccination programs.

Antibody Response to Varicella-Zoster Virus after Natural or Vaccine-Induced Infection

Abstract: The development of serum and nasopharyngeal antibody responses to varicella-zoster virus (VZV) was studied in groups of children after naturally acquired varicella or after immunization with the Oka strain of live attenuated VZV vaccine administered in varying doses via respiratory inhalation or subcutaneous injection. Natural infection, subcutaneous immunization, and respiratory inhalation of large doses of VZV vaccine consistently resulted in the development of VZV-specific IgG antibody responses in serum. Although the serum IgG antibody responses persisted for at least eight to 12 months (to date) after either form of infection, the antibody activity appeared to be four- to eight-fold higher after natural infection than after immunization. Transient IgG antibody responses were observed in serum after respiratory inhalation of smaller doses of VZV vaccine. Natural infection, but not VZV vaccine, was associated with the development of serum and nasopharyngeal IgA responses to VZV in most subjects.

Safety and efficacy of live and inactivated infectious bovine rhinotracheitis vaccines.

Abstract: Two commercial live virus infectious bovine rhinotracheitis (IBR) vaccines for intranasal administration and an inactivated polyvalent calf pneumonia vaccine were compared for safety and efficacy in calves against experimental IBR infections. All three products were clinically safe for use in young calves; a mild, transient, febrile response was induced by one of the live vaccines. Vaccinal virus was recovered for up to 16 days after vaccination from nasal secretions of all calves given live vaccine. Both live vaccines stimulated a serum neutralising antibody response, but the inactivated vaccine failed to elicit any serological response. Following intranasal challenge four months after the first dose of vaccine, all live virus vaccinates remained systemically healthy. A slight nasal discharge and a few rapidly healing ulcers of the nasal mucosa were the only abnormalities observed. Both the group given the inactivated vaccine and the unvaccinated controls developed clinical IBR with pyrexia, ocular and nasal discharges, severe ulceration of the nasal mucosa and tracheitis and tachypnoea to varying degrees of severity. Parenteral administration of dexamethasone six months after challenge induced reactivation of virus shedding followed by a rise in humoral antibody titre irrespective of the original vaccination history.

Human Diploid Cell Rabies Vaccine: Effectiveness of Immunization With Small Intradermal or Subcutaneous Doses

Abstract: To determine antibody responses to small doses of human diploid cell rabies vaccine (HDCV), we determined rabies antibody titers in 124 volunteers who had been vaccinated with one of five primary preexposure regimens. In a sixth group of 47 persons previously vaccinated with duck embryo rabies vaccine (DEV), we evaluated the booster response after a 0.1-mL dose of intradermal (ID) HDCV. Persons in all five groups undergoing primary immunization received three doses of vaccine, one each on days 0, 7, and 28. The dose and route of vaccination for the five groups included 1 mL intramuscular (IM), 0.1 mL ID (two subgroups), 0.1 mL subcutaneous (SC), and 0.25 mL SC. Adequate titers developed in all persons, irrespective of the route or quantity of vaccine. The geometric mean titers (IU/mL) on day 49 in those receiving primary regimens were 12.87 (1.0 mL IM), 7.44 (0.1 mL ID by syringe), 3.05 (0.1 mL by jet injector), 3.17 (0.1 mL SC), and 6.47 (0.25 mL SC). Titers on day 90, while lower, were still acceptable. Adequate antibody titers developed in all persons previously vaccinated with DEV after a single 0.1-mL ID dose of HDCV; however, higher titers developed at day 7 in those who had shown an adequate response to DEV in the past. Results of this study suggest that HDCV may be used ID or SC for primary preexposure rabies prophylaxis and ID for booster immunization. (JAMA1982;247:1138-1142)

Use of tetanus toxoid for the prevention of neonatal tetanus. 1. Reduction of neonatal mortality by immunization of non-pregnant and pregnant women in rural Bangladesh.

Abstract: PIP: 1 approach to the prevention of tetanus neonatorum (a leading cause of infant death throughout the world) is improving the quality of prenatal, obstetric, and postnatal maternal and child health services. Another complementary approach is the active immunization of women before or during pregnancy with tetanus toxoid. Work in progress at the Matlab field station of the International Center for Diarrheal Disease Research in Bangladesh (ICDDR,B) provided a unique opportunity to study the effectiveness of certain aspects of these 2 strategies. In 1974, during a field trial of cholera toxoid vaccine, 2 injections of an aluminum phosphate tetanus-diphtheria toxoid were provided as a control to a randomly assigned group of nonpregnant women. Beginning in June 1978, a program of immunizing women during pregnancy with aluminum phosphate-absorbed tetanus toxoid was initiated in conjunction with the implementation of a village based maternal and child health and family planning program in half of the same Matlab surveillance area. Throughout the period of these 2 programs, the ICDDR,B maintained an independent, longitudinal, vital registration system, identifying all births and deaths in the study area. In this analysis, all live births registered in the Maternal and Child Health-Family Planning and comparison areas during the September 1, 1978 until December 31, 1979 period were identified. These records were linked with any deaths recorded within 28 days of birth. The acceptance of tetanus vaccination during the 1974 cholera vaccine trial, by the mothers of these live births, was ascertained from the 1974 vaccine registers. The acceptance of vaccination during the 1978-1979 program was obtained from the field registers. For infants whose mothers had received 2 tetanus injections 48-64 months prior to delivery, the neonatal mortality rate was 63.8/l000 live births compared with 78.3/1000 for infants whose mothers did not receive tetanus immunization. Immunization of women with 2 tetanus injections during pregnancy reduced neonatal mortality rates to 42.8/1000, a reduction of 35.5/1000. Mortality on days 4-14 was reduced by about 70%. 1 injection during pregnancy did not appear to provide protection against tetanus neonatorum.

Canine parvovirus infection potentiates canine distemper encephalitis attributable to modified live-virus vaccine.

Abstract: Twelve gnotobiotic dogs from 2 litters were allotted to 3 groups. Group A dogs received a modified-live polyvalent (canine distemper, adenovirus type 2, and parainfluenza virus and Leptospira -canicola-icterohemorrhagiae bacterin) vaccine 3 days prior to oral inoculation with canine parvovirus (CPV). Group B dogs received CPV alone. Group C dogs received 1 dose of vaccine only. In none of the 9 CPV-inoculated dogs did clinical signs of CPV infection develop, although high serum antibody titers for CPV developed in all of them. However, in 2 of the 5 CPV-inoculated vaccinates, canine distemper virus encephalomyelitis subsequently developed. The results suggested that CPV exerts an immunomodulating effect on canine immune responses and may be responsible for vaccination failures in dogs.

Serum antibody response to pneumococcal vaccine in children with nephrotic syndrome

Abstract: Children with nephrotic syndrome are susceptible to serious pneumococcal disease and may be immunodeficient on the basis of abnormal humoral immune responses to natural antigens or immunoglobulin loss during relapse. As part of an ongoing study to evaluate pneumococcal anticapsular antibody concentration and immunologic competence, 27 steroid-responsive and six steroid-resistant patients with nephrotic syndrome, and 12 age-matched control subjects, were vaccinated with polyvalent pneumococcal vaccine. Antibody responders were defined as patients with at least a twofold increase in antibody after vaccination as well as an antibody concentration greater than 200 ng of anticapsular antibody nitrogen per milliliter (ngN/ml) after vaccination. Pneumococcal antibody concentrations before and after vaccination were significantly depressed in steroid-resistant patients when compared with control subjects (P less than .002) and with the steroid-responsive nephrotic syndrome group (P less then .001). Steroid-responsive nephrotic children who were not receiving corticosteroid therapy at the time of vaccination had significantly higher antibody concentrations to five pneumococcal types before vaccination and to seven types after vaccination compared with control subjects (P less than .05). Fewer steroid-responsive patients receiving corticosteroids achieved antibody concentrations greater than or equal to 200 ngN/ml against type 19F compared with patients not receiving steroids or with control subjects (P less than .05). These results suggest that pneumococcal vaccine is immunogenic in children with steroid-responsive nephrotic syndrome and may protect these patients from disease due to pneumococcal types contained in the vaccine.

Eradication of Poliomyelitis in the United States

Abstract: Mass immunization with oral poliovirus vaccine (OPV) was begun in the United States in 1963, and the least natural outbreak of poliomyelitis occurred in 1972. Since immunization programs fail to reach the total population, eradication has been achieved in the presence of a residual susceptible population of at least 5% (2-5 million children under the age of 15 years). It is proposed that the fade-out of wild polioviruses is explained by their disappearance during the winter, a low point in the yearly cycle of the virus. In the post-eradication era, the continued presence of millions of susceptible children and adults presents a constant potential hazard. Every effort should be made to maintain maximal levels of immunization with oral poliovirus vaccine and to prevent the reintroduction of wild polioviruses into the United States.

Atypical Measles Syndrome: Pathologic and Serologic Findings

Abstract: The clinical course of measles occurring in 17 adolescents who had previously received killed measles vaccine is described. All adolescents had a peripheral dermatitis. Fifteen had characteristic pulmonary infiltrates. Serologic study in six adolescents using immunoprecipitation of 35S-methionine-labeled measles virus antigens revealed that 5/6 acute sera lacked antibody to the hemolysin antigen whereas 5/6 sera contained antibody to hemagglutinin antigen. Skin biopsies, obtained from three patients, demonstrate a combination of an Arthus reaction and delayed hypersensitivity. The typical measles histologic complex was absent. Measles virions were seen in the deep dermal blood vessels. The serologic and histopathologic presentation of this disease indicates that killed vaccine does not adequately induce antibody to the hemolysin (F) which is necessary to prevent cell-to-cell spread of paramyxoviruses. Killed vaccine does, however, produce hemagglutinin antibody and simultaneously incites later hypersensitivity to wild virus infection, producing the unusual dermatopathologic reaction seen.

Measles immunity after revaccination: results in children vaccinated before 10 months of age.

Abstract: Measles immunity was studied in children in a private pediatric practice who had been revaccinated because they had received their primary measles vaccination before 1 year of age. Antibody was measured in 72 of these children who had received the first injection of live measles virus vaccine at less than 10 months of age, and the second at greater than 1 year of age. Of the 72 children, 29 (40%) had no detectable antibody and the geometric mean titer for the group was approximately 1:4. Of the children with low antibody titers, 15 were given a third injection of measles vaccine and five (33%) still did not respond. Cell-mediated immunity as indicated by lymphocyte transformation to measles antigen was measured in 11 of the children. Five (45%) had responses to measles antigen, but the responses did not correlate with the presence or absence of antibody. This study confirms the observation that revaccination is unsuccessful in many children who received measles vaccine in the first year of life, and shows that even a third injection of vaccine may fail to produce a significant antibody response.

Effect of Immunization Against Rubella on Lactation Products. I. Development and Characterization of Specific Immunologic Reactivity in Breast Milk

Abstract: The development of an immune response to rubella virus in milk, serum, and nasopharyngeal secretions was studied in lactating postpartum women after immunization with HPV-77 De5 or RA 27/3 live, attenuated rubella virus vaccine administered subcutaneously or intranasally. Over 69% of the women shed virus in milk after immunization. A predictable nasopharyngeal IgA and serum IgG antibody response to rubella virus was observed after subcutaneous or intranasal immunization with RA 27/3 vaccine. Little or no nasopharyngeal antibody response was seen after subcutaneous immunization with HPV-77 DE5 vaccine. A virus-specific IgA antibody response in milk was seen in all women. The presence of rubella virus in breast milk seemed to potentiate the peak levels of virus-specific antibody in the milk. Cellular immune reactivity to rubella virus in milk was observed in all vaccine groups. Thus, the virus-specific immune response induced in human milk after immunization with rubella virus vaccine may be intimately linked with the reactivity in bronchial lymphoid tissue.

Clinical Reactions and Serologic Responses After Vaccination with Whole-Virus or Split-Virus Influenza Vaccines in Children Aged 6 to 36 Months

Abstract: The reactogenicity and immunogenicity of whole-virus and split-product influenza vaccines were studied in 77 children between the ages of 6 and 36 months. Subjects initially received monovalent vaccine containing either A/USSR/77 (H1N1) antigen in 1978 or A/Brazil/78 (H1N1) antigen in 1979. One month later a trivalent preparation was given which contained the respective H1N1 antigen plus A/Texas/77 (H3N2) and B/Hong Kong/72 antigens. Temperatures of greater than or equal to 37.8 C (greater than or equal to 100 F) were observed more commonly after initial vaccination with whole-virus vaccine (35%) than after split-product vaccine (14%). No child had a temperature of greater than or equal to 39.4 C (103 F) or a febrile convulsion. The trivalent vaccines were more reactogenic than the monovalent vaccines although none of the reaction indices exceeded 0.9. The whole-virus vaccine appeared to be more immunogenic, especially in those children who were initially seronegative (preimmunization hemagglutination-inhibiting antibody titer (less than 5). Only 50% of children vaccinated with split-product vaccines with initial hemagglutination-inhibiting titers of less than 5 achieved titers of greater than or equal to 20 to the H1N1 antigen after two doses of vaccine compared with 97% in similar whole-virus vaccine recipients. The degree of antibody response to the A/Texas/77 component of the vaccines was greater than the response to the A/Brazil/78 or A/USSR/77 antigens.

Cell-mediated and humoral immunity induced by a live Francisella tularensis vaccine.

Abstract: Live attenuated Francisella tularensis vaccine induced long-lasting humoral and cell-mediated immune responses in all 13 subjects studied. Lymphocyte blast transformation reactivity to F. tularensis appeared 2 weeks after vaccination in most subjects and remained unchanged for up to 1.5 years. Similarly, in most recipients, antibodies against F. tularensis were detectable by both the enzyme-linked immunosorbent assay (ELISA) and the agglutination method from 2 weeks after vaccination, although diagnostically significant agglutination titers (greater than or equal to 80) were not detectable until 4 weeks after vaccination. Maximal agglutination titers of 80 to 2,560 appeared at 4 to 8 weeks, and in spite of decreasing tendency, titers as high as 320 were still present 1.5 years after vaccination. ELISA showed the simultaneous, but not parallel, appearance of different immunoglobulin classes, immunoglobulin M (IgM) reaching individual maximal values 1.8 months after vaccination on average, at the same time as agglutinating antibodies, 1 week earlier than IgA, and about 1 month earlier than IgG. All of these immunoglobulin classes persisted in significant amounts up to 1.5 years, with IgG generally dominant. Long-lasting IgA and IgM responses after vaccination, as also after infection, suggested that the serodiagnosis of tularemia generally requires two consecutive serum samples with a significant increase in the titer.

Effect of Immunization Against Rubella on Lactation Products. II. Maternal-Neonatal Interactions

Abstract: The transmission of rubella virus to newborn infants via the process of breast-feeding was studied after immunization of 16 breast-feeding and 10 non-breast-feeding mothers with HPV-77 DE5 live, attenuated rubella virus vaccine administered subcutaneously or RA 27/3 live, attenuated rubella virus vaccine administered intranasally or subcutaneously in the immediate postpartum period. Infectious rubella virus or virus antigen was observed in the breast milk of 11 (68%) of the 16 vaccinated, breast-feeding women studied. After maternal immunization, infectious rubella virus or virus antigen was recovered from the nasopharynx and throat of 56% of the breast-fed infants and from none of the non-breast-fed infants. Of the breast-fed infants, 25% showed transient seroconversion to rubella virus but without any clinical disease. No rubella virus-specific seroconversion was observed in the non-breast-fed infants. These observations provide strong support for the communicability of rubella virus to neonates via the process of breast-feeding.

Passive immunity in calf diarrhea: vaccination with K99 antigen of enterotoxigenic Escherichia coli and rotavirus.

Abstract: Twenty-four pregnant cows were vaccinated intramuscularly with K99 extract from enterotoxigenic Escherichia coli and inactivated rotavirus as follows: six cows were injected with 2 ml of oil-adjuvanted vaccine; six cows were injected with 0.5 ml of oil-adjuvanted vaccine; six cows were injected with 4 ml of aluminum hydroxide-adjuvanted vaccine twice with a four-week interval; and six cows were unvaccinated as controls. Calves born to these cows were challenged with enterotoxigenic E. coli at 6 to 18 h after birth. Serum and milk antibodies to K99 and rotavirus in cows vaccinated with either dose of oil vaccine were significantly increased until at least 28 days after calving. In cows vaccinated with alhydrogel vaccine, there was a significant K99 antibody increase in serum and in colostrum but not in milk and a significant rotavirus antibody increase only in colostrum. Five of six calves born to unvaccinated cows developed enterotoxic colibacillosis after challenge, and all excreted the challenge strain of enterotoxigenic E. coli. None of the 18 calves in the three vaccinated groups developed clinical colibacillosis, and fecal excretion of the challenge organism was reduced. A combined enterotoxigenic E. coli-rotavirus vaccine may prove useful in preventing some outbreaks of calf diarrhea.

Immunodepressive effects of trypanosomal infection in cattle immunized against contagious bovine pleuropneumonia.

Abstract: Groups of cattle infected singly with Trypanosoma vivax and T. congolense and, with a combination of T. vivax and T. congolense, were vaccinated against contagious bovine pleuropneumonia (CBPP) 6 weeks before or after infection. All animals were revaccinated 12 weeks after primary vaccination. The primary antibody responses in cattle vaccinated 6 weeks after infection with T. vivax and a combination of T. vivax plus T. congolense were slightly depressed in contrast to other groups which were similar in their response to the control group. Although secondary antibody responses developed in all infected groups, with a delay in those infected with T. congolense, they did not reach the levels of the controls. In spite of the slight depression in antibody responses, however, 50% of the vaccinated trypanosomal animals contracted CBPP on exposure to experimental infection while the vaccinated controls were immune. It is suggested that the protective immunity to CBPP engendered by vaccination is impaired during infection with African trypanosomes and that the level of antibody response to CBPP vaccination in trypanosomal animals does not reflect the degree of immunodepression. The importance of trypanosomiasis control in ensuring success of vaccination campaigns against CBPP is discussed.