The severity of human papillomavirus- 16/18 infection and its prevention to cervical cancer : A systematic review and meta-analysis

Abstract: Infectious diseases caused by human papillomavirus (HPV) are among the most common sexually transmitted diseases in the world. Currently, all countries of the WHO Eastern Mediterranean Region (EMRO) except the United Arab Emirates and Libya do not have a national vaccination program including the HPV vaccine. Cervical cancer risk can be reduced through the use of prophylactic HPV vaccines. Hence, the aim of this study was to examine the severity of HPV-16/18 infection in cervical cancer through a systematic review and to evaluate the effectiveness of vaccines against HPV-16/18 variants to prevent cervical cancer via a meta-analysis. Both the systematic review and meta-analysis contain nine relevant studies with 66154 and 78308 cervical cancer participants respectively. Statistical analyses were performed using pooled odds ratios (OR) with 95% confidence intervals (95% CI). Publication bias was examined using the funnel plot graph. The findings stated that overall 70% of cervical cancer was attributed to either HPV 16 or HPV 18. Heterogeneity for this meta-analysis was found to be I2= 80% with a p-value<0.01 and overall OR (odds ratio) was 0.09 (95% CI= 0.04-0.20) for the random effect model. The lower odds ratio (less than 1) indicated fewer occurrences of cervical cancer in the HPV 16/18 vaccinated group than in the unvaccinated individuals. The overall vaccination efficiency was found to be 91% from the odds ratio ((1-0.09)x100=91). Thus, the present findings support that a prophylactic vaccine against HPV16/18 prevents the severity of HPV-associated cervical cancer.