Vaccines are having an impact on disease evolution. Sometimes directly by mutations, reverting to virulence, sometimes by pressure driven evolution, sometimes by pressure on a specific pathogen, as seen in serotype replacement and disease replacement reduction in one gives room for increase and selection in another. Some of these might be of interest.
1 Vaccine-induced escape mutant of Hepatits B virus.
2 Mutations within the S gene of Hepatitis B Virus Transmitted from Mother to Babies Immunized with Hepatitis B Immune Globulin and Vaccine
3 Vaccine- and hepatitis B immune globulin- induced escape mutations of hepatitis B virus surface antigen
4 Prevalence of vaccine-induced escape mutants of hepatitis B virus in the adult population in China: A prospective study in 176 restaurant employees
5 Infections by hepatitis B surface antigen gene mutants in Europe and North America
6 Detection of Hepatitis B Surface Gene Mutation in Carrier Children with or without Immunoprophylaxis at Birth
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| These observations indicate that immune pressure exerted by immunoprophylaxis at birth may select for a mutant virus. |
7 Evolution of the oral polio vaccine strains in humans occurs by both mutation and intramolecular recombination.
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| In a companion study, some highly modified vaccine-associated case isolates were found to be not only multisite mutants, but also intramolecular recombinants of the vaccine strains. |
8
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| The clinical presentations were characterised by fever, myalgia, headache, and confusion, followed by severe multisystemic illnesses. Three patients died. Vaccine-related variants of yellow fever virus were found in plasma and cerebrospinal fluid of one vaccinee. |
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| The clinical features, their temporal association with vaccination, recovery of vaccine-related virus, antibody responses, and immunohistochemical assay collectively suggest a possible causal relation between the illnesses and yellow fever vaccination. |
9 Examination of the selective pressures on a live PRRS vaccine virus
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| The cDNA sequencing of the 20 vaccine virus revertants identified two single nucleotide mutations located in ORF5 and in ORF6 that we suggest are involved or at least linked to the attenuation of the vaccine virus and to the subsequent reversion to virulence. |
10 Avian coronavirus infectious bronchitis attenuated live vaccines undergo selection of subpopulations and mutations following vaccination
11 Natural Selection for rash-forming genotypes of the varicella-zoster vaccine detected within immunized human hosts
12 Effects of Vaccine Use in the Evolution of Mexican Lineage H5N2 Avian Influenza Virus
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| Though clinical signs were not observed with these LP viruses in experimental conditions, the shedding of H5 subtype LP viruses is of concern because of the potential for transmission to naïve flocks and the possibility of mutation to the HP form of the virus...Our study confirms the previous finding that chickens can be protected from clinical disease resulting from HPAI challenge even with a high degree of antigenic difference (Table 5). However, the level of virus shedding in the trachea correlated with the antigenic differences of vaccine and challenge strains. This discrepancy likely reflects the fact that vaccines for AI do not prevent infection but that antibodies in the bloodstream may effectively prevent the systemic phase of disease caused by HPAI viruses. |
13 Polymorphism in the Bordetella pertussis Virulence Factors P.69/Pertactin and Pertussis Toxin in The Netherlands: Temporal Trends and Evidence for Vaccine-Driven Evolution
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| These results suggest that vaccination has selected for strains which are antigenically distinct from vaccine strains. |
14 Imperfect vaccines and the evolution of pathogen virulence
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| Vaccines rarely provide full protection from disease. Nevertheless, partially effective (imperfect) vaccines may be used to protect both individuals and whole populations1, 2, 3. We studied the potential impact of different types of imperfect vaccines on the evolution of pathogen virulence (induced host mortality) and the consequences for public health. Here we show that vaccines designed to reduce pathogen growth rate and/or toxicity diminish selection against virulent pathogens. The subsequent evolution leads to higher levels of intrinsic virulence and hence to more severe disease in unvaccinated individuals. This evolution can erode any population-wide benefits such that overall mortality rates are unaffected, or even increase, with the level of vaccination coverage. In contrast, infection-blocking vaccines induce no such effects, and can even select for lower virulence. These findings have policy implications for the development and use of vaccines that are not expected to provide full immunity, such as candidate vaccines for malaria4. |
15 Microarray analysis of evolution of RNA viruses: Evidence of circulation of virulent highly divergent vaccine-derived polioviruses
16 Mapping the Antigenic and Genetic Evolution of Influenza Virus
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| Further, this approach offers a route to predicting the relative success of emerging strains, which could be achieved by quantifying the combined effects of population level immune escape and viral fitness on strain evolution. |
17 CDC-
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| In The Netherlands, as in many other western countries, pertussis vaccines have been used extensively for more than 40 years. Therefore, it is conceivable that vaccine-induced immunity has affected the evolution of B. pertussis. Consistent with this notion, pertussis has reemerged in The Netherlands, despite high vaccination coverage. Further, a notable change in the population structure of B. pertussis was observed in The Netherlands subsequent to the introduction of vaccination in the 1950s. Finally, we observed antigenic divergence between clinical isolates and vaccine strains, in particular with respect to the surface-associated proteins pertactin and pertussis toxin. Adaptation may have allowed B. pertussis to remain endemic despite widespread vaccination and may have contributed to the reemergence of pertussis in The Netherlands. |
18 Variation in the Bordetella pertussis Virulence Factors Pertussis Toxin and Pertactin in Vaccine Strains and Clinical Isolates in Finland
19 Imperfect vaccination: some epidemiological and evolutionary consequences.
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| An aim of some vaccination programmes is to reduce the prevalence of an infectious disease and ultimately to eradicate it. We show that eradication success depends on the type of vaccine as well as on the vaccination coverage. Vaccines that reduce the parasite within-host growth rate select for higher parasite virulence and this evolution may both increase the prevalence of the disease and prevent disease eradication. By contrast, vaccines that reduce the probability of infection select against virulence and may lead more easily to eradication. In some cases, epidemiological feedback on parasite evolution yields an evolutionary bistable situation where, for intermediate vaccination coverage, parasites can evolve towards either high or low virulence, depending on the initial conditions. These results have practical implications for the design and use of imperfect vaccines in public- and animal-health programmes. |
20 Origin and evolution of Georgia 98 (GA98), a new serotype of avian infectious bronchitis virus
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| Together with virus neutralization data, it appears that GA98 arose from immune selection caused by DE072 vaccine use. |
21 Evolution of Streptococcus pneumoniae Serotypes and Antibiotic Resistance in Spain: Update (1990 to 1996)
22 The out of Africa model of varicella-zoster virus evolution: single nucleotide polymorphisms and private alleles distinguish Asian clades from European/North American clades
23 Selection of Virus Variants and Emergence of Virus Escape Mutants after Immunization with an Epitope Vaccine
24 Impact of the Pneumococcal Conjugate Vaccine on Serotype Distribution and Antimicrobial Resistance of Invasive Streptococcus pneumoniae Isolates in Dallas, TX, Children From 1999 Through 2005
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| Conclusions: In Dallas, heptavalent pneumococcal conjugate vaccine reduced the incidence of IPD from 1999 to 2005 by reducing the incidence of vaccine-type disease. NVT serotypes, particularly 19A, were prevalent and more resistant to antimicrobials in 2004 and 2005. |
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| Conclusions.http://www.journals.uchicago.edu/na1...ities/2003.gifIntroduction of PCV7 into the routine infant immunization schedule in a community with a high prevalence of antimicrobial‐resistant pneumococci appears to reduce transmission of PCV7 vaccine serotypes and COT‐NS pneumococci but has no impact on overall carriage of pneumococci or carriage of PCN‐NS pneumococci. |
26
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| Conclusions: PPE in the post-PCV-7 era is more common, representing one-third of the IPD in children in UT. PPE is associated with significant morbidity and mortality. Serotype 1 remains the most common cause of PPE, but serotypes 3 and 19A are emerging. |
27 Levofloxacin-Resisitant Invasive Streptococcus pnuemonaie in the United States: Evidence for Clonal Spread and the Impact of Conjugate Pneumomoccal Vaccine
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| In conclusion, our study found a higher proportion of fluoroquinolone-resistant isolates related to the international clones than has been described in other studies (3, 9, 20). The introduction of the conjugate pneumococcal vaccine in 2000 and the demonstrated impact on the pneumococcal population and distribution of serotypes in adults (40) may have changed the course of an upward trend in fluoroquinolone resistance among invasive isolates, leading to the observed decrease in resistance in 2002, by reducing the absolute numbers of levofloxacin-resistant isolates within vaccine serotypes. Among vaccine serotypes, however, we found a continuously increasing resistance rate reaching 1.0% in 2002. Ongoing surveillance is needed to closely monitor the further evolution of fluoroquinolone resistance in this era of conjugate pneumococcal vaccine use. |
28 Incidence of Pneumococcal Disease Due to Non-Pneumococcal Conjugate Vaccine (PCV7) Serotypes in the United States during the Era of Widespread PCV7 Vaccination, 1998-2004
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| Widespread use of pneumococcal conjugate vaccine (PCV7) resulted in decreases in invasive disease among children and elderly persons. The benefits may be offset by increases in disease due to serotypes not included in the vaccine (hereafter, “nonvaccine serotypes”). We evaluated the effect of PCV7 on incidence of disease due to nonvaccine serotypes. |
29 Increased Antimicrobial Resistance Among Nonvaccine Serotypes of Streptococcus pneumoniae in the Pediatric Population After Introduction of 7-Valent Pneumococcal Vaccine in the United States
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| Conclusions: The proportion of S. pneumoniae isolates from U.S. pediatric patients covered by PCV7 decreased substantially in the 4 years after vaccine introduction. However, resistance to commonly used antimicrobials, including β-lactams and macrolides, as well as multidrug-resistant strains increased significantly among respiratory tract isolates of NVS. |
30 CDC-
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| In contrast, pneumococcal conjugate vaccine studies show considerable evidence of serotype replacement, as measured by nasopharyngeal carriage of nonvaccine type organisms. Increases in the carriage of nonvaccine serotypes have occurred in three major ongoing clinical trials of pneumococcal conjugate vaccines. In Gambia, carriage of nonvaccine serotypes was 79% in children receiving three doses of a pneumococcal conjugate vaccine (compared with 42.5% in controls) (5). In trials of a 9-valent vaccine in South Africa, carriage of nonvaccine serotypes increased from 21% in controls to 39% in vaccine recipients (6). |
31 Strain replacement in an epidemic model with super-infection and perfect vaccination
32 Vaccine-induced pathogen strain replacement: what are the mechanisms?
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| Vaccination, which intensifies and modifies selection by protecting hosts against one or more pathogen strains, can drive the emergence of new dominant pathogen strains—a phenomenon called vaccine-induced pathogen strain replacement. |
33 Commensals Upon Us
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| A battle to control and curtail bacterial infectious diseases is being waged in our hospitals and communities through antibiotic therapies and vaccines targeting specific species. But what effects do these interventions have on the epidemiology of infections caused by the organisms that are part of our natural microbial flora? Gram-positive and gram-negative bacteria appear as new disease agents from among commensal flora. These include vancomycin resistant enterococci (VRE), community-associated methicillin resistant Staphylococcus aureus (CA-MRSA), non-vaccine invasive serotypes of Streptococcus pneumoniae, new strains of non-type b Haemophilus influenzae and multi-drug resistant Escherichia coli. These examples illustrate how clinical improvements and widespread use and misuse of antibiotics have pushed evolution, allowing normally non-pathogenic strains to become infectious disease threats to human health. |
34
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| Introduction of Haemophilus influenzae type b (Hib) conjugate vaccines in late 1980s–early 1990s made a dramatic effect on the incidence of invasive Hib disease among children in many industrialized countries with routine Hib immunization programs. However, cases of vaccine failure and an increased susceptibility to invasive Hib as well as non-type b H. influenzae disease have been consistently reported among individuals with various congenital and acquired immunodeficiencies. Remarkably, in the 21st century, diseases due to non-type b strains of H. influenzae are becoming relatively more frequent than before. Despite the overall successful immunization against Hib, some indigenous populations, i.e. Australian Aboriginal and North American Indian children still experience increased rates of invasive H. influenzae disease. In order to monitor the evolving nature of invasive H. influenzae disease, carefully documented surveillance data is required to capture the true magnitude of the problem. Developing new vaccines against non-type b H. influenzae is a potential solution to protect some vulnerable populations against the invasive disease. |
35 Effect of Community-Wide Conjugate Pneumococcal Vaccine Use in Infancy on Nasopharyngeal Carriage through 3 Years of Age
36 Human polymicrobial infections
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| Recently, Gili Regev-Yochay (JAMA 2004; 292: 716—20) and Debby Bogaert (Lancet 2004; 363: 1871—72), and their colleagues, suggested another interaction: microbial interference—the ability of Streptococcus pneumoniae carriage to protect against Staphylococcus aureus carriage, and the inverse effect of pneumococcal conjugate vaccination on the increased carriage of Staph aureus and Staph-aureus-related disease. Strep pneumoniae carriage protected against Staph aureus carriage, and the bacterial interference could be disrupted by vaccinating children with pneumococcal conjugate vaccines that reduced nasopharyngeal carriage of vaccine-type Strep pneumoniae. |
I'm just looking for something a little more concrete that I can pass on.
