My medical research, besides epidemiological measures, has had a major focus on vaccines, their effectiveness, safety, and implementation.
Introduction: Vaccines mitigate the severity of the diseases, prevent infections, and reduce the complications associated with infections.Following the 2012 measles campaign in Zambia, a cross sectional study was conducted to estimate coverage rates for measles, Oral Polio Vaccine (OPV), Vitamin A, and de-worming.Materials and Methods: Using a cluster sampling method, 9 children were sampled for measles vaccination, Vitamin A and de-worming from each of the 40 clusters, and sampled 9 children in each of the 22 out of 40 clusters for OPV vaccination where it was distributed.Estimates and their 95 % confidence intervals are reported.Results: Data were available for analysis from 359 parent/care taker children pairs to determine measles coverage, 190 for OPV supplementation coverage, 270 for Vitamin A coverage, and 336 for de-worming coverage.Most of the children were aged 1 or 2 years (57.8% in measles sample, 62.9% in OPV sample, 61.8% in Vitamin A sample, and 63.6% in deworming sample).A total of 345 (96.1%) children were vaccinated against measles.A total of 157 (83.1%) children received OPV, 257 (95.5%) received Vitamin A, and 313 (93.4%) were de-wormed.About 6 in 10 of the respondents reported that the health worker was the source of information and the key messages were encouraging children to go for vaccination and advantages for vaccination. Conclusion:The 2012 measles campaign in Zambia was a great success but continued efforts are needed to adhere to the World Health Organization/United Nations Children's Fund (WHO/UNICEF) strategy to control measles.
On February 28, 1998, Dr. Andrew Wakefield published an article in the Lancet on 12 children “with a history of pervasive developmental disorder and intestinal symptoms. Onset of behavioral symptoms was associated, by the parents, with measles, mumps, and rubella vaccination in eight of the 12 children.” Though not claiming the MMR vaccine caused the symptoms, adding what parents thought certainly raised the possibility. Statements and articles by Wakefield suggested he believed such a link probable. Vaccination rates plummeted in the UK and outbreaks of vaccine preventable diseases followed. Investigative journalist Brian Deer uncovered dishonest and unethical medical practices by Wakefield, resulting in Wakefield losing his medical license. Rather than appeal the decision, Wakefield wrote a book, “Callous Disregard: Autism and Vaccines – The Truth Behind a Tragedy,” wherein he claims loss of his license was a political attempt to silence his criticism of vaccine safety. This paper examines the validity of Wakefield’s claims. A careful review of publicly available information makes it clear that Wakefield’s claims regarding vaccine safety are wrong. It is hoped that this review will be used by doctors and public health personnel to encourage parents hesitating to have their children vaccinated to question anti-vaccination claims in general, given that many proponents often refer to Wakefield as an authority and display in their own writings and pronouncements similar erroneous claims.
Swine influenza (SI) is an acute, highly contagious, respiratory disease of swine caused by influenza A viruses.In addition, SI infections possess significant human public health concerns as they may serve as intermediate host for the generation of new pandemic viruses.Vaccination is still the primary method for the prevention and control of SI.Currently, commercially available vaccines against SI are a combination of inactivated swine influenza viruses (SIVs) with oil adjuvant.Their application induces mainly humoral immune response, which may not be protective against virus variation in the field.In contrast, application of live attenuated influenza vaccines (LAIV) mimics natural infection and induces strong, cell-mediated and humoral immunity.Furthermore, LAIV induces cross-protective immunity against different subtypes of influenza A viruses and are currently unavailable for SI.Using reverse genetics technology we generated mutant SIVs with the modified cleavage site within hemagglutinin (HA) segment.These viruses are fully dependent on the presence of human neutrophil elastase for their growth in tissue culture and are completely attenuated when administered to pigs.Furthermore, application of these live attenuated, elastase-dependent swine influenza viruses as a live vaccines resulted in the significant protective humoral (systemic and mucosal), cell-mediated and cross-reactive immunity in pigs.The purpose of this review is to provide recent advances in SIV live vaccine development by modifying the hemagglutinin cleavage site.Here, we review the design and generation of elastasedependent mutant SIV by reverse genetics; evaluation of its genetic stability and pathogenicity in pigs; evaluation of its immunogenicity and protection efficacy after intratracheal and intranasal application to diverse SIV challenges including 2009 pandemic H1N1 virus.
The child immunization card is an inexpensive yet effective instrument for systematically recording the vaccines received by a child. Moreover, the card can enhance health professionals' ability to make clinical decisions, empower parents/caregivers in the health care of their children, and support public health monitoring. Unfortunately, the child immunization card is too often underutilized or inappropriately used by parents and health care workers and therefore does not always fulfil its intended purpose. National immunization programmes should be encouraged to procure cards in conjunction with other necessary vaccination supplies and to more actively promote the issuance and appropriate use of the card.
By adulthood repeated exposure to Plasmodium falciparum, the causative agent of the most severe form of malaria in humans, can induce semi-immunity to clinical infection.During pregnancy, however, there is a striking recurrence of severe disease, a syndrome described as pregnancy-associated malaria (PAM).This is caused by P. falciparum-infected erythrocytes binding to receptors on the placental endothelium that are expressed uniquely during pregnancy.This subset of parasites binds by virtue of expressing a cell surface antigen that is the ligand for the corresponding endothelial receptor, thereby providing a selective pressure for its clonal expansion.The antigen also triggers a protective antibody-mediated immune response.With subsequent pregnancies and further exposure to these variant parasites, antibodies develop earlier and women may experience milder infections.Women with PAM exhibit more severe malaria infections than do non-gravid women, with 2,500-10,000 deaths each year due to haemolytic anaemia.PAM also has a detrimental effect on the foetus, increasing the risk of low birth weight, which causes 60,000-200,000 infant deaths annually in sub-Saharan Africa.Current research aims to produce a vaccine to stimulate development of antibodies which would be protective against infection with wild-type parasites.This is hampered by significant diversity in variant surface antigens and available vaccine candidates may only protect women living in malaria-endemic areas.While placental-parasite interactions are not sufficiently understood, incremental progress is being made towards producing an effective vaccine.This review focuses on the molecular structures involved in binding to consider the prospects for a vaccine mimicking naturally-acquired immunity to PAM.
The Gram negative bacterium, Vibrio cholerae (Vc) causes cholera, an enteric disease that has killed untold numbers of humans.In the 19 th century, whole-cell (W-C) cholera vaccines were tested in humans.Field trials (1960s-70s) of injected, killed W-C (kW-C) Vc showed cholera-specific immune responses (antibodies, Abs) could be induced with a single dose in certain cohorts, but more durable immunity was sought with oral cholera vaccines.Newer, killed (two doses) and later modified live (one dose) W-C cholera vaccines for oral delivery were developed and extensively tested.After over 200 years, no consensus exists as to what are protective Vc antigens or how to identify them.An enduring cholera vaccine for children <5 years of age and Vc-antigen naïve individuals is still needed.The cholera outbreak in Haiti underscores some unresolved issues associated with the current cholera vaccines.Annually, is there enough cholera vaccine for those who need it?Who needs to be vaccinated and when?Given the displacement of populations during flooding like in Pakistan or in Haiti due to an earthquake, can a single dose of the kW-C cholera vaccine function to prevent or to contain an outbreak?What does 'working' entail: solely preventing deaths, or that plus long term immunity?Can a single formulation of Vc antigens be used for endemic or epidemic cholera which may require reactive vaccination for epidemics, but prophylactic vaccination for endemic cholera?The immunologic realities given the logistic issues for the different needs of a cholera vaccine are discussed.
Previous accounts of the 1916 devastating epidemic have been faulty.The unique features of the epidemic and its sudden appearance have never been explained.A New York laboratory was passaging poliovirus in primate brains, a technique which increased pathogenicity.I propose that highly virulent virus escaped and caused the epidemic.Scientists, technical and animal house staff were unaware that they could be infected by poliovirus which could then infect others.All laboratory workers must be constantly reminded of the dangers which can arise from the escape of pathogens from their work.
In the past, immunization programs worldwide mainly focused on the delivery of infant and early childhood vaccines.An increasing awareness of the importance of investing in adolescents' health has led to the introduction of new vaccines targeted specifically to adolescents over the last ten years: this has improved the adolescent's opportunities to protect from certain diseases for which they are at an increased risk.Safe and effective vaccines against human papilloma virus, Neisseria meningitides and Bordetella pertussis are recommended in many parts of the world; nevertheless, vaccination coverage in this age group is relatively low compared to coverage in infants.Barriers to adolescent immunization are believed to be complex and multifactorial but overcoming these barriers will be of primary importance for the future.
Despite remarkable improvement in global immunisation coverage during the past 30 years, progress has not been uniform. The reasons underlying sub-optimal progress are many, but perhaps one of the most important and overlooked is that national immunisation programmes too often have not received the appropriate support and tools to facilitate the gathering, managing, analysing and reporting of data in a manner that enables taking action to ensure quality and sustainability of the programme. However, it is not only an issue of lacking capacity within these programmes, but also one of political will and commitment to invest in data collection, data management, analysis and reporting. The Decade of Vaccines provides a unique opportunity to highlight the importance and increase support of data and information systems that feed the sound evidence base needed to move global immunsation forward during the next ten years.
Many vaccines existing today provide strong protection against a wide variety of infectious organisms, and these consist of either live attenuated or inactivated microorganisms. Most of these vaccines were developed empirically and there has not been a clear understanding of the immunological principles that contribute to this success. Recent advances in systems biology are being applied to the study of vaccines in order to determine which immunological parameters are the best predictors of success. New approaches to vaccine development include the identification of peptide epitopes and the manipulation of the immune response to generate the most appropriate response. Vaccines are being developed to prevent and/or treat such conditions as cancer and autoimmunity in addition to infectious diseases. Vaccines targeting this diverse group of diseases may need to elicit very different types of immune responses. Recent advances in our understanding of the functions of dendritic cells (DC) and cytokines in orchestrating qualitatively different immune responses has allowed the design of vaccines that can elicit immune responses appropriate for cancer, autoimmunity or infectious organisms. This review will focus on recent advances in the ways DC and cytokines can be used to develop the most appropriate and effective vaccines.
This paper presents findings from a study conducted in 2007 and 2008 in two states in India: Andhra Pradesh and Gujarat.The objectives of the study were to: (i) design effective and appropriate HPV vaccine delivery systems for 10-to 14-year-old girls; (ii) design a communication strategy for HPV vaccine delivery; and (iii) devise an HPV vaccine advocacy strategy.The study populations included girls, parents, and local-, district-, and national-level stakeholders.A mixture of group discussions, visual representation techniques, face-to-face interviews, desk and health facility record reviews, field observations, and consultative workshops were used to collect the data.Study findings showed that the policymakers, health care providers, parents, and adolescents were aware and concerned about cervical cancer; would welcome vaccination if safe, effective, affordable, and accessible.Health systems did not require large infrastructure investments to introduce HPV vaccine; basic cold chain and logistic equipment were available.New outreach systems for adolescent girls need to be tested through demonstration projects.No policies would compromise the introduction of HPV vaccination.An HPV vaccine program, requiring public education and provider training, could be delivered.Policymakers' safety and vaccine efficacy concerns can be addressed through targeted advocacy efforts.Three broad approaches were suggested: (i) merge HPV vaccination with already established immunization services; (ii) package HPV immunization with adolescent health services or as a part of a cancer control service; and (iii) deliver HPV vaccinations through either routine immunization services or a campaign using schools as sites for school-going girls and anganwadi or village health centers for non-school-going girls.
The possible role of the most abundant structural protein of Rift Valley fever virus (RVFV), the nucleocapsid protein (NP), in inducing protective immune responses has only been evaluated preliminarily in mice but not in any natural host species.In this study we demonstrate that a soluble recombinant RVFV subunit NP in combination with adjuvants (ISA50, Alhydrogel, TiterMax Gold or SaponinQ) is highly immunogenic in mice and sheep but the level of clinical protection and virus replication in mice after lethal challenge was dependent on the adjuvant used.Immunization with NP in combination with Alhydrogel conferred 100% protection against morbidity, mortality and viral replication in mice, but sterilizing immunity could not be achieved in sheep with any NP/adjuvant combinations used.Although this is the first study showing that sterilizing immunity can be elicited in mice immunized with a RVFV subunit nucleocapsid protein, our findings seem to suggest that mice might not be the best animal model for studying the protective ability of RVF subunit vaccines.The results of our study also emphasize the importance of adjuvant selection when evaluating subunit RVF vaccines.
The last two centuries have seen an extraordinary reduction in the morbidity and mortality due to infectious diseases as a result of improvements in health and hygiene-related conditions and the introduction of vaccinations. Vaccines against infectious diseases with a human reservoir can have the following beneficial effects : control, elimination, eradica- tion and extinction of the disease. Vaccines have facilitated the eradication of smallpox in 1980 and a massive reduction in cases of poliomyelitis, of which only 1,655 were recorded worldwide in 2008. The elimination of poliomyelitis in the European region was certified by the WHO in 2002. The essential conditions for the elimination of communicable diseases are political commitment, the implementation of vaccination programmes and exhaustive disease surveillance.
An important number of viruses (measles, rubella, human parvovirus B19, herpes simplex, varicella zoster, en- teroviruses, dengue and others) can cause exanthematic diseases. Laboratory diagnosis of exanthems due to viral infec- tions include the identification of the disease-causing virus (isolation, antigen detection or nucleic acid detection) and the determination of a specific serological response (seroconversion or specific IgM). The aim of virus isolation is the recovering of infectious viruses, being useful for molecular epidemiological studies. It is of application for measles, rubella, enterovirus, herpes simplex and varicella-zoster. However, due to its methodological complications, it is not of application in most laboratories. For some viruses, isolation is not practical, because there is no cell substrate available (Epstein-Barr, parvovirus B19). An alternative to viral isolation is the detection of antigens on clinical specimens (dengue). Thirdly, nucleic acid detection is a very useful approach for diagnosing viral exanthems, spe- cially when multiplex assays recognising measles, rubella and parvovirus B19, or enterovirus and herpesvirus, are used. The best tool for the serological diagnosis is the detection of IgM, since it provides a rapid diagnosis during the first days of the disease. However it has some drawbacks when used to diagnose viral rashes (the presence of rheumatoid factor and specific IgG; the multiple reactivity due to polyclonal stimulation of memory lymphocytes; the cross-reactivity between viruses causing a similar clinical picture; the IgM synthesis in herpesvirus reactivations). In such cases, confirmatory serological approaches (establishment of seroprofiles, or avidity assays) are necessary. Both direct and indirect methods must be considered as complementary and the results obtained for each one should be evaluated in the context of the clinical profile and epidemiological history.
This issue of the Open Vaccine Journal includes a set of articles based on the "Measles, Rubella and Mumps in the Elimination Era Workshop" organized by CIBERESP, (Centros de Investigación Biomédica en Red Epidemiología y Salud Pública).CIBERESP is one of nine CIBERs in Spain.CIBERs are funded by the Carlos III Health Institute, Madrid, and are defined as National Biomedical Research Centres in a specific area of knowledge.CIBERESP, which was formally created in November 2006 and commenced its activity in January 2007, focuses on epidemiology and public health.CIBERESP, like the other CIBERs in Spain, is considered as a new type of research organization whose main objective is to add critical mass by agglutinating assets from different institutions, and to function as a research network.CIBERESP is organized in various areas according to research field:-Infectious diseases and international health, -Chronic diseases, -Environmental, occupational and reproductive health, and -Evaluation of health policy and services.One of the aims of the CIBERs ESP is to strengthen already excellent research groups by expanding their collaborative activities and finances and, ultimately, increase the research output and productivity of participating groups and therefore of Spain as a whole.Another aim of CIBERESP is to organize activities for the transfer of knowledge.In May 2008, in Barcelona, the area of infectious diseases and international health organized a workshop aimed at reviewing the situation of measles, rubella and mumps in Spain and internationally.The workshop was directed at staff working in the surveillance of immunopreventable diseases from the Spanish Autonomous Regions and from the National Centers of Epidemiology and Microbiology, microbiologists, pediatricians, general practitioners and other professionals involved in the detection and control of these diseases.The workshop was organized as a series of round tables on measles, rubella and mumps and the contents of these presentations, enriched by the comments of attendees, are now presented as original articles or reviews.Because experience gained from control and elimination programs is useful not only for the specific disease at which they are aimed, but also for other diseases, we hope that the articles in this special issue will be of interest for all those working in the prevention and control of immunopreventable diseases.
In 2000, the circulation of indigenous measles was interrupted in Catalonia as a result of the activities of the elimination programme introduced in 1991. However, various transmission chains occurred in the indigenous population after the introduction of an imported case, and this caused a total change in the existing situation of elimination. The objective of this study was to analyze the epidemiological and clinical characteristics of the measles outbreak in Catalonia in 2006. Cases reported between August 28 2006 and July 8 2007 were collected. Cases were microbiologically confirmed by determination of measles-specific IgM and/or detection of the viral genome in urine samples. A total of 381 cases of measles were confirmed, representing an incidence of 6.6 per 100,000 inhabitants. Laboratory confirmation was made in 87.1% of the cases and all specimens sequenced belonged to the D4 genotype. A total of 89.5% of the cases occurred in non-vaccinated people, above all in infants aged <16 months.
