Showing papers on "Vaccination published in 1989"

Nature of Protective Immunity to Francisella tularensis

Abstract: Tularemia is caused by the facultative intracellular bacterium Francisella tularensis. Attenuated live vaccines, such as F. tularensis LVS (live vaccine strain), afford good--although not complete--protection; how to judge the degree of this protection has long been a problem. Both natural infection and vaccination result in immunospecific and long-lasting humoral and cell-mediated immunity. The latter is the crucial protective mechanism, whereas the humoral response protects only against strains of reduced virulence, such as those used in the vaccines. Immune serum has been used to screen for structures of F. tularensis with the ability to induce a protective immune response. This immune serum is, however, primarily directed toward antigens different from those involved in cell-mediated immunity. Serum antibodies from primed individuals recognize carbohydrate capsule antigens of F. tularensis, whereas T lymphocytes recognize membrane polypeptides of the organism. The preparation of membrane polypeptides from F. tularensis is now facilitated by the availability of a capsule-deficient mutant of F. tularensis LVS. In vitro, several membrane polypeptides of the mutant stimulate T lymphocytes from vaccinees and from naturally infected individuals. Further studies of the mechanisms of induction of protective immunity should focus on these membrane polypeptides.

Vaccine protection against simian immunodeficiency virus infection.

Abstract: Rhesus monkeys were immunized by multiple inoculations with purified, disrupted, noninfectious simian immunodeficiency virus (SIV) in adjuvant. Immunized monkeys developed anti-SIV antibodies detectable by whole-virus ELISA and by immunoblot reactivity; these antibodies had weak neutralizing activity. One week after the last immunization, monkeys were challenged with 200-1000 animal infectious doses of uncloned, live SIV. The same strain of SIV that was used for vaccination was also used for challenge. Anamnestic antibody responses and SIV recovery from peripheral blood were used to evaluate infection following the live virus challenge; two of six vaccinated monkeys showed no evidence of infection following the live virus challenge. Transfusion of 10 ml of whole blood from these two into uninfected, naive rhesus monkeys did not result infection of the recipients, providing further support for the lack of infection in the two previously vaccinated animals. Four of four unvaccinated control monkeys inoculated with these doses of live SIV became infected and three of these died with AIDS 118-258 days after infection. Only one of the six vaccinated monkeys has died to date. In situ hybridization with lymph node biopsy specimens suggested that the virus load was much higher in control macaques than in vaccinated macaques. These results indicate that vaccination with inactivated whole virus can protect macaques against challenge with live SIV. Furthermore, they provide hope that vaccine protection against human AIDS virus infection may be possible.

Vaccination against ovine cysticercosis using a defined recombinant antigen.

Abstract: Cysticercosis caused by larval tapeworms is a major public health problem and a cause of substantial economic losses in the farm-animal industries. Taenia ovis in sheep is a particularly important example. Immunity to reinfection with the larvae has a central role in regulating natural transmission of the parasites, and vaccination with antigens from the early larval oncosphere stage can induce complete protection against infection. As it is impractical to obtain enough oncospheres for a commercial vaccine against these tapeworms, an alternative approach is to use recombinant DNA methods to generate a cheap and plentiful supply of antigens. We report here the expression in Escherichia coli of complementary DNA encoding T. ovis antigens as fusion proteins with the Schistosoma japonicum glutathione S-transferase. Vaccination of sheep with these fusion proteins gave significant, although not complete, immunity against challenge infection with T. ovis eggs. Commercial development of a vaccine is being pursued.

Progress in vaccines against typhoid fever.

Abstract: The widely available heat-phenol-inactivated whole cell typhoid vaccine, which provides approximately 65% protection, has limited usefulness because of the adverse reactions it evokes. In contrast, several new typhoid vaccines promise protection without reactogenicity. Attenuated oral vaccine Ty21a has been evaluated in three field trials of efficacy in Santiago, Chile, involving 530,000 schoolchildren. Three doses of Ty21a in an enteric-coated formulation given within one week provided 69% efficacy for at least four years. Fewer doses conferred less protection, while adding a fourth dose significantly enhanced protection; increasing the interval between doses did not improve protection. Large-scale vaccination with Ty21a appeared to cause a herd-immunity effect. Ty21a has reached the stage of being a practical tool for public health. With respect to other vaccines, the safety and immunogenicity of an auxotrophic (Aro-,Pur-) Salmonella typhi mutant (strain 541Ty) has recently been evaluated. Lastly, parenteral purified Vi polysaccharide of S. typhi was safe and immunogenic and provided 64%-72% protection (for at least 17-21 months) in controlled field trials in Nepal and South Africa.

Vaccination against Hepatitis B: Comparison of Three Different Vaccination Schedules

Abstract: Three different hepatitis B vaccination schedules employing injections at months 0, 1, 2, and 12, at months 0, 1, and 6, or at months 0, 1, and 12 were compared in 89 healthy young adults. Concentrations of antibodies to hepatitis B surface antigen (anti-HBs) after the third injection were dependent on the interval between the second and the third dose; geometric mean titers (GMTs) in the three groups were 53 IU/l, 5,846 IU/l, and 19,912 IU/l, respectively, when the third dose was given at month 2, 6, or 12. Whereas the anti-HBs responses to the third dose at month 6 or 12 were typical booster reactions, the kinetics after a third dose given at month 2 resembled those after only two doses but on a significantly higher level. A fourth dose given at month 12 to the individuals vaccinated at months 0, 1, and 2 led to a prompt anti-HBs response similar in height to the response in those vaccinated at months 0, 1, and 12. Thus, for achieving a high anti-HBs concentration guaranteeing its long-lasting persistence, vaccination at months 0, 1, and 12 seems to be preferable to vaccination at months 0, 1, and 6. For individuals at high risk of hepatitis B infection, vaccination at months 0, 1, 2, and 12 might be considered for obtaining an optimal early seroconversion as well as long-term protection.

Persistence of Immunity to Varicella in Children with Leukemia Immunized with Live Attenuated Varicella Vaccine

Abstract: To determine the safety and efficacy of varicella vaccine, we studied 437 children in remission from leukemia who were immunized with live attenuated varicella virus. Three hundred one of the patients received two doses of vaccine and 136 received a single dose of vaccine from 1 of 10 lots from two manufacturers. The patients have been followed for an average of three years (range, one to six). Seroconversion occurred in 88 percent of the 437 children after the first dose of vaccine and in 98 percent after one or two doses. The proportions of patients who were seronegative after one, three, and five years were 20, 25, and 30 percent, respectively, with little change over time in the geometric mean titers of specific antibody (6.3, 6.5, and 5.7, respectively). Chickenpox has been documented in 36 vaccinated patients (8 percent) who had 3 to 640 vesicles (mean, 100), mild illness, and no complications. Of the 83 vaccinated patients exposed to varicella within their families, 11 had chickenpox; the attack rate was 14 percent (8 percent among seropositive patients, 29 percent among seronegative patients). There was no relation between the time since vaccination and either the attack rate or the severity of the breakthrough illness. Two doses of vaccine appeared to be no more effective than a single dose. Of the 372 patients receiving maintenance chemotherapy when immunized, 149 (40 percent) had a rash, which was treated with acyclovir in 16 children (4 percent) and became a severe febrile illness in 4. These reactions were not fatal and were all associated with vaccine lots, the use of which has since been discontinued. We conclude that in children in remission from leukemia, varicella vaccine is safe and induces an immunity to chickenpox that persists for more than three years.

Immunogenicity and efficacy testing in chimpanzees of an oral hepatitis B vaccine based on live recombinant adenovirus

Abstract: As a major cause of acute and chronic liver disease as well as hepatocellular carcinoma, hepatitis B virus (HBV) continues to pose significant health problems world-wide. Recombinant hepatitis B vaccines based on adenovirus vectors have been developed to address global needs for effective control of hepatitis B infection. Although considerable progress has been made in the construction of recombinant adenoviruses that express large amounts of HBV gene products, preclinical immunogenicity and efficacy testing of candidate vaccines has remained difficult due to the lack of a suitable animal model. We demonstrate here that chimpanzees are susceptible to enteric infection by human adenoviruses type 7 (Ad7) and type 4 (Ad4) following oral administration of live virus. Moreover, after sequential oral immunization with Ad7- and Ad4-vectored vaccines containing the hepatitis B surface antigen (HBsAg) gene, significant antibody responses to HBsAg (anti-HBs) were induced in two chimpanzees. After challenge with heterologous HBV, one chimpanzee was protected from acute hepatitis and the other chimpanzee experienced modified HBV-induced disease. These data demonstrate the feasibility of using orally administered recombinant adenoviruses as a general approach to vaccination.

Efficacy and Safety of Vaccination of Marrow Transplant Recipients with a Live Attenuated Measles, Mumps, and Rubella Vaccine

Abstract: Long-term immunity to measles, mumps, and rubella viruses was studied in 57 patients after allogeneic bone marrow transplantation. Among patients who were seropositive at the time of transplant, 51% had retained antibodies to measles, 42% had retained antibodies to mumps, and 76% had retained antibodies to rubella 2 y later. There was no difference in the ability to retain antibodies to these viruses between patients with and those without chronic graft-versus-host disease (GVHD). Twenty seronegative patients without active chronic GVHD or ongoing immunosuppressive treatment were vaccinated with a live attenuated trivalent vaccine against measles, mumps, and rubella. No early or late side effects were detected after the vaccinations. The percentages of patients who seroconverted after vaccination were 77%, 64%, and 75% for measles, mumps, and rubella, respectively. Vaccination of transplant recipients with a live attenuated vaccine against measles, mumps, and rubella is safe and usually effective 2 y after transplant if the patients do not have active chronic GVHD or ongoing immunosuppressive treatment at the time of vaccination.

The influence of HIV infection on antibody responses to a two-dose regimen of influenza vaccine.

Abstract: We studied whether a two-dose regimen of inactivated influenza virus vaccine was more effective than a single dose in inducing protective hemagglutinationinhibition antibody responses in patients infected with human immunodeficiency virus (HIV). Participants included subjects with acquired immunodeficiency syndrome, subjects with acquired immunodeficiency syndrome—related complex, and HIV-seropositive individuals with either lymphadenopathy only or no symptoms. Control subjects were HIV-seronegative heterosexuals and HIV-seronegative homosexuals. Two doses of inactivated influenza vaccine containing 15 μg of the hemagglutinin of influenza A/Taiwan/1/86(H1N1), A/Leningrad/360/86(H3N2), and B/Ann Arbor/1/86 were administered intramuscularly in the deltoid region 1 month apart. The second dose of vaccine did not significantly increase the frequency or magnitude of antibody responses of either HIV-seropositive or HIV-seronegative subjects over that achieved by a single dose. The two-dose regimen induced a protective level (≥1:64) of hemagglutination-inhibition antibody to influenza A(H1N1) or (H3N2) virus less often in subjects with symptomatic HIV infection than in uninfected control subjects (39% vs 87% or 46% vs 97%, respectively). Our results suggest that a substantial proportion of individuals with symptomatic HIV infection might remain unprotected from influenza, even after immunization with a two-dose regimen. ( JAMA . 1989;262:779-783)

Duration of immunogenicity and efficacy of hepatitis B vaccine in a Yupik Eskimo population.

Abstract: In 1981, a hepatitis B virus vaccine demonstration project was conducted in 1630 Yupik Eskimos in southwest Alaska. Levels of antibody to hepatitis B surface antigen and markers for hepatitis B virus infection in vaccinees were monitored yearly for 5 years. After 5 years of follow-up, 19% of those who initially had an immune response to vaccine of 10 sample ratio units or greater subsequently had levels of antibody to hepatitis B surface antigen lower than 10 sample ratio units. During the 5 years after the first dose of vaccine, in three responders and one person with an antibody to hepatitis B surface antigen response lower than 10 sample ratio units, antibody to hepatitis B core antigen developed, and the level of antibody to hepatitis B surface antigen was boosted. Hepatitis B surface antigen did not develop in any subjects, and none had clinical hepatitis. In the 5 years following the demonstration project, the annual incidence of hepatitis B virus infection decreased from 50 cases per 1000 population before the vaccine trial to 0.45 per 1000. ( JAMA . 1989;261:2362-2366)

Protective Efficacy of a Recombinant DNA Hepatitis B Vaccine in Neonates of HBe Antigen—Positive Mothers

Abstract: We have assessed the protective efficacy of a recombinant DNA hepatitis B vaccine alone in infants of women who were positive for the surface antigen and the e antigen. The infants received a 10-μg dose of the vaccine within 12 hours of birth and additional doses 1, 2, and 12 months later. No significant adverse reactions to vaccination were observed and the vaccine was highly immunogenic. Only 2 (3.6%) of the 55 infants followed up to 13 months became chronically infected with the hepatitis B virus, as evidenced by the persistent presence of hepatitis B surface antigen in serum samples. Without immunoprophylaxis, 65% to 90% of such infants would become chronic carriers. Immunization with a recombinant vaccine without concomitant administration of hepatitis B immunoglobulin, therefore, considerably decreased the incidence of the carrier state. (JAMA. 1989;261:3278-3281)

Protection of Peruvian children against rotavirus diarrhea of specific serotypes by one two or three doses of the RIT 4237 attenuated bovine rotavirus vaccine.

Abstract: Researchers evaluated the degree of protection against diarrheal illness especially diarrhea caused by rotavirus by 1 2 or 3 doses of RIT 4237 attenuated rotavirus vaccine in 391 children 2-18 months old. This was a randomized placebo controlled double blind study that followed the infants for 18 months. During the 1st week field workers visited the children at least 3 times/week and thereafter twice a week. None of the children experienced any side effects from the vaccine. In the placebo group the diarrhea rate stood at 10.6 episodes/child year while the rates for the 1 dose and 3 dose groups were significantly lower (9.1 and 9.4 respectively). Microbiologists tested 3586 stool samples or rectal swabs for rotavirus using the double sandwich ELISA technique. They detected rotavirus in 117 (3%) of these. Vaccine efficacy (VE) for diarrheal episodes with several isolates including rotavirus was 15% 10% and 25% for 1 2 and 3 vaccine doses respectively. VE for episodes with rotavirus as the only isolate was 22% 24% and 40% for 1 2 and 3 vaccine doses respectively. VE was higher when infants were immunized with 3 doses during the 1st year of life (11/83 child years vs. 21/82.4 child years; VE=48%) than in the 2nd year (5/42 child years vs. 6/44.9 child years; VE=11%). The RIT 4237 vaccine had a greater efficacy against serotype 1 rotavirus than against serotype 2 and when evaluating the protection of 3 doses against the more severe diseases caused by serotype 1 in rotavirus only cases the VE was 89%. In addition 1 dose provided significant protection. Any future rotavirus vaccines must protect against severe disease of all significant rotavirus serotypes especially in developing countries.

Rabies virus epitopic variation: use in ecologic studies.

Abstract: Publisher Summary People living in the industrialized societies of Europe and North America are less at risk from dying of rabies than of being struck by lightning.. Before dismissing rabies as a trivial public health problem, however, it must be noted that the low incidence of human rabies is not the consequence of disease eradication; rather it is the result of control programs comprising massive preexposure and postexposure prophylaxis and dog immunization. Recent advances in vaccine technology have suggested new avenues of rabies control that, in addition to preventing human infection, may also actually eradicate the disease from its animal reservoir, thus eliminating the need for human and domestic animal prophylaxis. Oral vaccination of red foxes by field baiting has dramatically reduced rabies in some European countries and may have eliminated it from some areas.

Global Control of Hepatitis B Through Vaccination: Role of Hepatitis B Vaccine in the Expanded Programme on Immunization

Abstract: Hepatitis B is a disease that affects people throughout the world, and over 200 million are persistent carriers of the hepatitis B virus (HBV). The chronic sequelae of this infection include chronic active hepatitis, cirrhosis, and primary hepatocellular carcinoma. The development of safe and highly effective hepatitis B vaccines now provides the means by which HBV infection, including the HBV chronic carrier state, can be prevented and the related mortality significantly reduced. The cost of these vaccines has significantly decreased and will soon approach levels at which the cost-effectiveness (cost per death prevented) of hepatitis B vaccine will be similar to that of other childhood vaccines. Integration of hepatitis B vaccine into the Expanded Programme on Immunization for mass vaccination of infants in areas where HBV infection is endemic and morbidity is high would be the most effective means of providing the coverage necessary for effective control and prevention.

Measles and measles immunity in children infected with human immunodeficiency virus.

Abstract: The development of measles vaccination recommendations for immunodeficient children infected with human immunodeficiency virus requires assessment of disease risk and the risks and benefits of vaccination. Measles in 4 such children resulted in 3 severe pneumonias and 1 death despite previous immunization in 2. Antibody to measles as determined by enzyme-linked immunosorbent assay was present in 3 (12.5%) of 24 children studied retrospectively and developed in only 2 (25%) of 8 children immunized and followed up prospectively. The sera of 9 of 24 children had antibody when tested by sensitive hemagglutination inhibition. Measles developed in 2 of 6 children who had negative enzyme-linked immunosorbent assay results and positive hemagglutination inhibition results. No adverse consequences of measles immunization were detected. Although the immunogenicity of measles vaccine in children infected with human immunodeficiency virus was low and vaccine failure occurred, the apparent safety provides the rationale for immunization in the face of a potentially fatal disease. Since neither documented immunization nor low-level antibody guaranteed immunity to measles, we recommend passive postexposure immunoglobulin prophylaxis for all children infected with human immunodeficiency virus.

The dentist and infectious diseases: a national survey of attitudes and behavior.

Abstract: Two national surveys of infection control practices in 1986 and 1988 suggest several trends. A massive educational effort has brought about impressive acceptance and use of the hepatitis vaccine. Dramatic changes have occurred in respect to use of gloves and other barrier techniques. However, increased understanding of HIV infection has not, in the years surveyed, totally eradicated irrational fears about this disease.

Immunization of Pregnant Women with a Polysaccharide Vaccine of Group B Streptococcus

Abstract: Immunization of pregnant women with a polysaccharide vaccine of group B streptococcus is a promising strategy for the prevention of perinatal infections caused by group B streptococci. To explore the feasibility of this strategy, we vaccinated 40 pregnant women at a mean gestation of 31 weeks with a single 50-microgram dose of the Type III capsular polysaccharide of group B streptococcus. The only adverse effect detected was a mild local reaction in nine women (22 percent). Of the 35 women with low or unprotective antibody levels before immunization (less than 2 micrograms per milliliter), 20 (57 percent) responded to the vaccine. The geometric mean antibody level rose from 1.3 to 7.1 micrograms per milliliter four weeks after vaccination (P less than 0.02), and these levels persisted at delivery and three months post partum. Sixty-two percent of the vaccine-induced immunoglobulin in the mothers was IgG, which readily crosses the placenta. Infant antibody levels in cord serum correlated directly with maternal antibody levels at delivery (r = 0.913, P less than 0.001). Of the 25 infants born to women who responded to the vaccine, 80 percent continued to have protective levels of antibody at one month of age and 64 percent had protective levels at three months. Serum samples from infants with greater than or equal to 2 micrograms of antibody to Type III group B streptococcus per milliliter uniformly promoted efficient opsonization, phagocytosis, and bacterial killing in vitro of Type III strains. This effect could be mediated exclusively by the alternative complement pathway. Although this vaccine with an overall response rate of 63 percent is not optimally immunogenic, we conclude that maternal immunization is feasible and can provide passive immunity against systemic infection with Type III group B streptococcus in the majority of newborns. Larger trials with better vaccines will be required to evaluate the safety and clinical effectiveness of this strategy.

Interleukin 2 acts as an adjuvant to increase the potency of inactivated rabies virus vaccine.

Abstract: Interleukin 2 (IL-2) occupies a central position in the cascade of events involved in the immune response. We were interested in determining whether IL-2 could function as an adjuvant to vaccination, to increase the immune response to vaccine immunogens. Using the National Institutes of Health test for rabies vaccine potency, we found that daily systemic administration of IL-2 in conjunction with inactivated rabies virus can increase the potency of vaccination in outbred mice at least 25-fold, as measured by survival following challenge with virulent rabies virus. Enhanced protection is not correlated with an increase in virus-neutralizing antibody titers, and we suggest that IL-2 acts to increase the cellular immune response to vaccination.

An explosive point-source measles outbreak in a highly vaccinated population. Modes of transmission and risk factors for disease.

Abstract: In 1985, 69 secondary cases, all in one generation, occurred in an Illinois high school after exposure to a vigorously coughing index case. The school's 1,873 students had a pre-outbreak vaccination level of 99.7% by school records. The authors studied the mode of transmission and the risk factors for disease in this unusual outbreak. There were no school assemblies and little or no air recirculation during the schooldays that exposure occurred. Contact interviews were completed with 58 secondary cases (84%); only 11 secondary cases (19%) of these may have had exposure to the index case in the classrooms, buses, or out of school. With the use of the Reed-Frost epidemic model, only 22-65% of the secondary cases were likely to have had at least one person-to-person contact with the index case during class exchanges, suggesting that this mode of transmission alone could not explain this outbreak. A comparison of the first 45 cases and 90 matched controls suggested that cases were less likely than controls to have provider-verifiable school vaccination records (odds ratio (OR) = 8.1) and more likely to have been vaccinated at less than age 12 months (OR = 8.6) or at age 12-14 months (OR = 7.0). Despite high vaccination levels, explosive measles outbreaks may occur in secondary schools due to 1) airborne measles transmission, 2) high contact rates, 3) inaccurate school vaccination records, or 4) inadequate immunity from vaccinations at younger ages.

Measles Outbreak Among Unvaccinated Preschool-Aged Children: Opportunities Missed by Health Care Providers to Administer Measles Vaccine

Abstract: A measles outbreak in an inner-city area primarily involved preschool-aged children younger than 5 years of age. The reasons why 31 unvaccinated preschool children with measles disease had not been vaccinated were investigated. For some patients, health care providers missed opportunities to vaccinate eligible patients against measles. Of the 26 patients whose full immunization status was known, ten (38%) were vaccinated with diphtheria and tetanus toxoids and pertussis vaccine and/or oral poliovirus vaccine at a time when they could have received measles vaccine simultaneously, according to recommendations of the Immunization Practices Advisory Committee and the American Academy of Pediatrics. In addition, five of ten health care providers interviewed missed at least one opportunity to administer measles vaccine because of a minor illness that was not a contraindication to vaccination. Unvaccinated patients were more likely to receive health care in the public sector, have single mothers, and have parents who had no knowledge of existing vaccines; they were less likely to be age-appropriately immunized with other antigens. If measles immunization levels among preschool children in the United States are to be increased, education of both health care providers and parents, coupled with innovative strategies targeted to preschool children, particularly of low socioeconomic groups in inner cities, are needed.

Natural or vaccine-induced antibody as a predictor of immunity in the face of natural challenge with influenza viruses.

Abstract: A study of influenza in residential schools provided the opportunity to assess the significance of antibody as a predictor of immunity. Five hundred and fifty-six pupils from 8 schools were included in the investigations, and the outcome for these children in 27 naturally occurring outbreaks of influenza was analysed. The outbreaks comprised 5 caused by strains of influenza A H3N2, 10 caused by strains of influenza A H1N1, and 12 caused by strains of influenza B. On 8 occasions a second outbreak of the same serotype occurred in a school. There was a general correlation between the presence of antibody to the outbreak strain and protection from infection. For each of the three influenza virus serotypes the infection rate in those with no detectable antibody was approximately 80%. Those with past experience of the virus but no antibody to the outbreak strain experienced lower infection rates (62% overall) but the infection rates were lowest in those with intermediate and high level antibody to the challenge strain (18% overall). Vaccine was used by three of the schools. The effect of antibody derived from recent experience, either natural or vaccine-induced, on subsequent challenge with a drifted strain i.e. one showing antigenic drift away from the previous strain, was compared. Intermediate or high level antibody to the challenge strain in those who had experienced a recent natural infection was associated with a low infection rate (9%). A similar level of antibody produced in response to vaccination was associated with a significantly higher infection rate (23%: P less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Human Serum Antibody Responses to Bordetella pertussis Infection and Pertussis Vaccination

Abstract: We used an immunoblotting technique to compare the serum antibody responses to pertussis toxin (PT), filamentous hemagglutinin (FHA), a 69-kilodalton (kDa) adenylate cyclase-associated protein (69 KD protein), and Bordetella pertussis outer membrane proteins (OMPs) following either B. pertussis infection or immunization with whole-cell pertussis vaccine. Infection and vaccination induced nearly equally intense antibody responses to PT and to FHA, but vaccination induced stronger antibody responses to the 69 KD protein and to many OMPs. The importance of serum antibody responses to the 69 KD protein and to B. pertussis OMPs other than PT and FHA in conferring immunity to pertussis after vaccination is unknown. Serum antibody responses to PT following either infection or vaccination were almost exclusively to the 28-kDa enzymatic subunit (SI) and only rarely and weakly to the lesser molecular weight binding subunits (S2-S5).

Measles prevention and control in emergency settings.

Abstract: Outbreaks of measles continue to be a common occurrence among refugee and famine-affected children in emergency relief camps. Extremely high measles-associated mortality rates have been reported from refugee camps--where undernutrition is common--in several countries over the past 10 years. Mortality from measles is, however, preventable, and immunization against the disease is a high priority in emergency relief programmes, second only in importance to the provision of adequate food rations. All children aged 6 months to 5 years should be immunized with measles vaccine as soon as they enter an organized camp or settlement. Should supplies of measles vaccine be inadequate, children in feeding centres, or those otherwise identified as undernourished, are the top priority for immunization. The occurrence of measles in a camp is not a contraindication to conducting an immunization campaign. Strong coordination by a designated lead agency is needed if such campaigns are to be successful; however, cooperation with the local expanded programme on immunization is essential to ensure that existing cold chain equipment, training protocols, and management manuals are used. If additional equipment is necessary, a complete immunization kit developed by the Office of the United Nations High Commissioner for Refugees, the World Health Organization, and Oxfam can be procured from Oxfam headquarters in the United Kingdom. Vitamin A supplements should be given routinely at the time of measles immunization in situations where malnutrition is severe. Mortality and morbidity in children with clinical measles can be reduced by administering high doses of vitamin A.

Immunological adjuvants and vaccines

Abstract: Vaccination, chiefly responsible for the eradication of smallpox and the control of poliomyelitis and German measles in man and of foot-and mouth, Marek's and Newcastle disease in domestic animals, remains the best answer to infectious diseases. Early vaccines were live wild type organ isms but these have been largely replaced by attenuated or killed organisms or by purified components (subunits) thereof. More recently, developments in recombinant DNA techniques, the advent of monoclonal antibodies and progress in our understanding of the immunological structure of proteins, have laid the foundations for a new generation of vaccines. For instance, subuni t vaccines have been produced through gene cloning and a number of peptides mimicking small regions of proteins on the outer coat of viruses and capable of eliciting virus neutralizing antibodies, have been synthes ized. Such vaccines are defined at the molecular level, can elicit immune responses controlling specific infectious organisms and are, thus, potent ially free of the problems inherent in conventional ones. However, because subunit and peptide vaccines are only weakly or non-immunogenic, they re quire the presence of immunological adjuvants. These are a diverse array of agents that promote specific humoural and/or cell-mediated immunity responses to antigens. This book contains the proceedings of the 1st NATO Advanced Studies Institute "Immunological Adjuvants and Vaccines" held in Cape Sounion Beach, Greece during 24 June-5 July, 1988."