HPV Vaccination Analysis

From a worldwide public health prospective, reducing deaths from cervical and other HPV induced cancers is arguably the most important goal of an HPV vaccination program. Sustainable vaccination programs that protect as many women as possible from persistent infection by at least HPV16 and 18 would seem to be the most practical means of approaching this goal (Schiller and Haefliger 2006).

Two prophylactic vaccinations against HPV have been licened by US Food and Drug admintration for use of young women ( Gardasil, a quadrivalent vaccine produced by Merk and approved in 2006 and Cervarix, a bivalent produced by Glaxo smith Kline and approve d in 2009). Both vaccines protect against HPV 16 and 18 and Gardasil also protects against HPV and 11

At each PCR cycle it is possible to measure the amount of amplified product. The detection is performed using non-specific fluorescent dyes that intercalate with any double-stranded DNA or using sequence-specific DNA probes. After each cycle, to estimate the DNA concentration, the fluorescence is measured with a detector and is compared with a control used as reference. Given its capacity to detect the presence and abundance of a specific DNA sequence, RT-PCR techniques have been developed to quantify HPV-DNA in clinical samples (Molijn et al. 2005) and (Dutra et al.

Most laboratories use consensus primers targeting the L1 region, since it is the most conserved part of the genome, referring to the assay as L1 consensus PCR. Amplification of each of the primer sets will result in different size amplicons and consequently can result in a variation in sensitivity for detection of certain HPV types, particularly when samples contain multiple genotypes. There are numerous L1 consensus PCR primers that can be used (Morris 2005). Other example of consensus primers is the GP5/6, incorporating one forward and one reverse primer aimed at short regions of homology conserve amongst HPV types 1, 6, 8, 11, 13, 16, 18, 30, 31, 32 and 33 To improve efficiency, part of these sequences were used to elongate GP5 and GP6 at their 3’ ends to generate the primers GP5+/6+. The GP5+/6+ primer set generates a 150bp amplicon and reveales an improved HPV detection, reflected by a 10 to 100 fold higher sensitivity, compared with the GP5/6 (Dutra et al. 2012). The third option is to combine a number of distinct forward and reverse primers, aimed at the same position of the viral genome. These primers do not contain random degeneracies, but may contain inosine, which matches with any nucleotide. Using a defined mixture of non-degenerate primers has the advantage that the oligonucleotides can be synthesized with high reproducibility, and PCR is performed at