Ronald W. Jones

Efficacy of a quadrivalent prophylactic human papillomavirus (types 6, 11, 16, and 18) L1 virus-like-particle vaccine against high-grade vulval and vaginal lesions: a combined analysis of three randomised clinical trials

BACKGROUND Vulval and vaginal cancers among younger women are often related to infection with human papillomavirus (HPV). These cancers are preceded by high-grade vulval intraepithelial neoplasia (VIN2-3) and vaginal intraepithelial neoplasia (VaIN2-3). Our aim was to do a combined analysis of three randomised clinical trials to assess the effect of a prophylactic quadrivalent HPV vaccine on the incidence of these diseases. METHODS 18 174 women (16-26 years) were enrolled and randomised to receive either quadrivalent HPV6/11/16/18 L1 virus-like-particle vaccine or placebo at day 1, and months 2 and 6. Individuals underwent detailed anogenital examination at day 1, 1 month after dose three, and at 6-12-month intervals for up to 48 months. Suspect genital lesions were biopsied and read by a panel of pathologists and vaccine HPV type-specific DNA testing was done. The primary endpoint was the combined incidence of VIN2-3 or VaIN2-3 associated with HPV16 or HPV18. Primary efficacy analyses were done in a per-protocol population. FINDINGS The mean follow-up time was 3 years. Among women naive to HPV16 or HPV18 through 1 month after dose three (per-protocol population; vaccine n=7811; placebo n=7785), the vaccine was 100% effective (95% CI 72-100) against VIN2-3 or VaIN2-3 associated with HPV16 or HPV18. In the intention-to-treat population (which included 18 174 women who, at day 1, could have been infected with HPV16 or HPV18), vaccine efficacy against VIN2-3 or VaIN2-3 associated with HPV16 or HPV18 was 71% (37-88). The vaccine was 49% (18-69) effective against all VIN2-3 or VaIN2-3, irrespective of whether or not HPV DNA was detected in the lesion. The most common treatment-related adverse event was injection-site pain. INTERPRETATION Prophylactic administration of quadrivalent HPV vaccine was effective in preventing high-grade vulval and vaginal lesions associated with HPV16 or HPV18 infection in women who were naive to these types before vaccination. With time, such vaccination could result in reduced rates of HPV-related vulval and vaginal cancers.

Gene coding assignments for growth restriction, neutralization and subgroup specificities of the W and DS-1 strains of human rotavirus.

Gene coding assignments for growth restriction, neutralization and subgroup specificities were determined for two human rotavirus strains, DS-1 and W, which represent two distinct serotypes. The 4th gene segment of both viruses was associated with restriction of growth in cell culture. The 9th gene segment of W virus and 8th segment of DS-1 were associated with serotype specificity, while the 6th gene segment of W virus was associated with subgroup specificity.

Comparative Sequence Analysis of the Genomic Segment 6 of Four Rotaviruses Each with a Different Subgroup Specificity

The nucleotide sequences of the genes that code for the major inner capsid protein, VP6, of the human rotavirus strain 1076 (subgroup I), porcine rotavirus Gottfried (subgroup II), equine rotavirus strain H-2 (non-I/II) and equine rotavirus strain FI-14 (both subgroups I and II) have been determined. The sixth segment positive-stranded RNA encodes a protein of 397 amino acids in all strains with the exception of strain H-2 in which it encodes a protein of 399 amino acids. Alignment of amino acid sequences of the VP6 protein of strain FI-14 and subgroup II rotaviruses (Wa and Gottfried) indicates a high degree of homology (94%), while homology between strain FI-14 and subgroup I rotaviruses (SA-11, RF and 1076) was somewhat less (90 to 92%). On the other hand a high degree of conservation of amino acid sequence (95 to 97%) was observed between the H-2 strain and subgroup I rotaviruses. Five regions that may contribute to subgroup epitopes were identified. Region A (amino acids 45, 56) and region C (amino acids 114, 120) may contribute to subgroup I epitopes and regions B (amino acids 83, 86, 89, 92), D (amino acids 312 or 314, 317 or 319) and E (amino acids 341 or 343, 350 or 352) may contribute to subgroup II epitopes. When analysed using the Western blot technique monoclonal antibodies specific for VP6 epitopes shared by all rotaviruses were observed to react with both monomeric and trimeric forms of VP6, while monoclonal antibodies specific for a subgroup I or II epitope reacted only with the trimeric form of VP6. This observation and the sequence analyses suggest that subgroup antigenic specificity is determined by conformational epitopes produced by the folding of VP6 or the interaction between VP6 monomers.

Human Papillomavirus and Cervical Cancer in Australasia and Oceania: Risk-factors, Epidemiology and Prevention

The region encompassing Australasia and Oceania, including Australia, New Zealand, Fiji and Papua New Guinea, is a diverse one with respect to ethnicities, cultures and behaviours. It includes countries with comprehensive cervical cytology screening programmes which can be credited with significant reductions in cervical cancer incidence and mortality, and countries with no prevention programmes and significantly higher incidence and mortality. As elsewhere in the world, human papillomavirus (HPV)-16 and 18 are the commonest high-risk types, with the highest rates in women under 25 years of age. These two high-risk HPV types are found most frequently in cervical cancers and high-grade dysplasias, although there are minimal data for many countries in Oceania. In April 2007, Australia became the first country worldwide to commence a government funded universal HPV vaccine programme. The school-based programme targets 12-year old females in an ongoing schedule, with a catch-up programme up to 26 years of age, to be completed in mid-2009. Vaccine introduction has been comprehensively rolled out, with around 75% uptake of the complete vaccine schedule among school-girls in the first year of this initiative. This represents a successful model for other countries. We present data on cervical cancer, risk factors and prevention strategies, including epidemiology of HPV and HPV vaccine strategies.

Rotavirus Serotype G9 Strains Belonging to VP7 Gene Phylogenetic Sequence Lineage 1 May Be More Suitable for Serotype G9 Vaccine Candidates than Those Belonging to Lineage 2 or 3

ABSTRACT A safe and effective group A rotavirus vaccine that could prevent severe diarrhea or ameliorate its symptoms in infants and young children is urgently needed in both developing and developed countries. Rotavirus VP7 serotypes G1, G2, G3, and G4 have been well established to be of epidemiologic importance worldwide. Recently, serotype G9 has emerged as the fifth globally common type of rotavirus of clinical importance. Sequence analysis of the VP7 gene of various G9 isolates has demonstrated the existence of at least three phylogenetic lineages. The goal of our study was to determine the relationship of the phylogenetic lineages to the neutralization specificity of various G9 strains. We generated eight single VP7 gene substitution reassortants, each of which bore a single VP7 gene encoding G9 specificity of one of the eight G9 strains (two lineage 1, one lineage 2 and five lineage 3 strains) and the remaining 10 genes of bovine rotavirus strain UK, and two hyperimmune guinea pig antisera to each reassortant, and we then analyzed VP7 neutralization characteristics of the eight G9 strains as well as an additional G9 strain belonging to lineage 1; the nine strains were isolated in five countries. Antisera to lineage 1 viruses neutralized lineage 2 and 3 strains to at least within eightfold of the homotypic lineage viruses. Antisera to lineage 2 virus neutralized lineage 3 viruses to at least twofold of the homotypic lineage 2 virus; however, neutralization of lineage 1 viruses was fourfold (F45 and AU32) to 16- to 64-fold (WI61) less efficient. Antisera to lineage 3 viruses neutralized the lineage 2 strain 16- to 64-fold less efficiently, the lineage 1 strains F45 and AU32 8- to 128-fold less efficiently, and WI61 (prototype G9 strain) 128- to 1,024-fold less efficiently than the homotypic lineage 3 viruses. These findings may have important implications for the development of G9 rotavirus vaccine candidates, as the strain with the broadest reactivity (i.e., a prime strain) would certainly be the ideal strain for inclusion in a vaccine.

Construction and characterization of human rotavirus recombinant VP8* subunit parenteral vaccine candidates

Two currently licensed live oral rotavirus vaccines (Rotarix® and RotaTeq®) are highly efficacious against severe rotavirus diarrhea. However, the efficacy of such vaccines in selected low-income African and Asian countries is much lower than that in middle or high-income countries. Additionally, these two vaccines have recently been associated with rare case of intussusception in vaccinated infants. We developed a novel recombinant subunit parenteral rotavirus vaccine which may be more effective in low-income countries and also avert the potential problem of intussusception. Truncated recombinant VP8* (ΔVP8*) protein of human rotavirus strain Wa P[8], DS-1 P[4] or 1076 P[6] expressed in Escherichia coli was highly soluble and was generated in high yield. Guinea pigs hyperimmunized intramuscularly with each of the ΔVP8* proteins (i.e., P[8], P[4] or P[6]) developed high levels of homotypic as well as variable levels of heterotypic neutralizing antibodies. Moreover, the selected ΔVP8* proteins when administered to mice at a clinically relevant dosage, route and schedule, elicited high levels of serum anti-VP8* IgG and/or neutralizing antibodies. Our data indicated that the ΔVP8* proteins may be a plausible additional candidate as new parenteral rotavirus vaccines.

Serotypic characterization of outer capsid spike protein VP4 of vervet monkey rotavirus SAff11 strain

SummaryThe vervet monkey rotavirus SAff11, a prototype strain of group A rotaviruses, has been shown to possess VP7 serotype 3 specificity but its neutralization specificity with regard to the other outer capsid protein VP4 has not been elucidated. We thus determined its VP4 specificity by two-way cross-neutralization with guinea pig antiserum prepared with a single gene substitution reassortant that had only the VP4-encoding gene from the simian rotavirus SAff11 strain and remaining ten genes from human rotavirus DS-1 strain (G serotype 2). The SAff11 VP4 was related antigenically in a one-way fashion to rhesus monkey rotavirus MMU18006 VP4 (a P5B strain) and marginally to human and canine rotavirus VP4s with P serotype 5A specificity. In addition, the SAff11 VP4 was shown to be distinct antigenically from those of other known P serotypes (1–4, and 6–11) as well as those of uncharacterized equine, lapine, and avian rotavirus strains. The SAff11 VP4 is thus proposed for classification as a P5B serotype.

Identification of parental origin of cognate dsRNA genome segment(s) of rotavirus reassortants by constant denaturant gel electrophoresis

Rotaviruses are the single most important etiologic agents of severe diarrhea in infants and young children worldwide. They possess a triple capsid morphology and a genome of 11 segments of double-stranded (ds) RNA. During the course of the development of various live, attenuated reassortant rotavirus vaccines, we often experienced difficulty in identifying the parental origin of certain genome segment(s) of a reassortant vaccine candidate. Various assays have been utilized for determination of the parental origin of reassortant virus genes, including polyacrylamide gel electrophoresis (PAGE), DNA and/or RNA hybridization assays and gene sequence analysis. The traditional PAGE is simple and easy to perform, however, it is common to find that certain cognate dsRNA segment(s) cannot be differentiated by this assay due to a high degree of sequence homology among different rotavirus strains. Constant denaturant gel electrophoresis (CDGE) is one of several methods that have been used to screen DNA fragments for small sequence changes or point mutations. By using the CDGE, we were successful in partially denaturing rotavirus dsRNA thereby changing the physical properties of the genome segment(s) in the gel and thus differentiating the cognate genome segment(s) of rotavirus reassortants. The CDGE provides a simple and reliable assay system for identification of parental gene origins of a rotavirus reassortant.

The VP7 Genes of Two G9 Rotaviruses Isolated in 1980 from Diarrheal Stool Samples Collected in Washington, DC, Are Unique Molecularly and Serotypically

ABSTRACT In a retrospective study of archival diarrheal stool samples collected from 1974 to 1991 at Childrens Hospital National Medical Center, Washington, DC, we detected three genotype G9P[8] viruses in specimens collected in 1980, which represented the earliest human G9 viruses ever isolated. The VP7 genes of two culture-adapted 1980 G9 viruses were phylogenetically related closely to the lineage 2 G9 virus VP7 gene. Unexpectedly, however, the VP7s of the 1980 G9 viruses were more closely related serotypically to lineage 3 VP7s than to lineage 2 VP7, which may be supported by amino acid sequence analyses of the VP7 proteins.

Construction of four double gene substitution human × bovine rotavirus reassortant vaccine candidates: Each bears two outer capsid human rotavirus genes, one encoding P serotype 1A and the other encoding G serotype 1, 2, 3, or 4 specificity

Previously four human × bovine rotavirus reassortant candidate vaccines, each of which derived ten genes from bovine rotavirus UK strain and only the outer capsid protein VP7‐gene from human rotavirus strain D (G serotype 1), DS‐1 (G serotype 2), P (G serotype 3), or ST3 (G serotype 4), were developed [Midthun et al., (1985); Journal of Virology 53:949–954; (1986): Journal of Clinical Microbiology 24:822–826]. Such human × bovine reassortant vaccines should theoretically provide antigenic coverage for the four epidemiologically most important VP7(G) serotypes 1, 2, 3, and 4. In an attempt to increase the antigenicity of VP7‐based human × animal reassortant rotavirus vaccines which derive a single VP7‐encoding gene from the human strain and the remaining ten genes from the animal strain, we generated double gene substitution reassortants. This was done by incorporating another protective antigen (VP4) of an epidemiologically important human rotavirus by crossing human rotavirus Wa strain (P serotype 1A), with each of the human × bovine single VP7‐gene substitution rotavirus reassortants. In this way four separate double gene substitution rotavirus reassortants were generated. Each of these reassortants bears the VP4‐envoding gene from human rotavirus Wa strain, the VP7‐encoding gene from human rotavirus strain D, DS‐1, P, or ST3, and the remaining nine genes from bovine rotavirus strain UK. The safety, antigenicity, and protective efficacy of individual components as well as combinations of strains are currently under evaluation. J. Med. Virol. 51:319–325, 1997.