Human papillomavirus genotypes in cervical cancer and vaccination challenges in Zimbabwe
HPV Genotypes: Nyasha Chin’ombe1*, Natasha L Sebata1, Vurayai Ruhanya1 and Hilda T Matarira2
Abstract
Cervical cancer is one of the major causes of morbidity and mortality in women in Zimbabwe. This is mainly due to the high prevalence of high-risk human papillomavirus (HPV) genotypes in the population. So far, few studies have been done that showed the presence of high-risk genital HPV genotypes such as 16, 18, 31, 33, 52, 58 and 70 in Zimbabwean women with cervical cancer. The prevalence of HPV DNA in women with cervical cancer has been shown to range from 63% to 98%. The high-risk HPV 16, 18, 31, 33 and 58 were the most common in all the studies. The introduction of the new HPV vaccines, HPV2 and HPV4, which protect against HPV genotypes 16 and 18 into Zimbabwe is likely to go a long way in reducing deaths due to cervical cancer.
However, there are few challenges to the introduction of the vaccines. The target population for HPV vaccination is at the moment not well-defined. The other challenge is that the current HPV vaccines confer only type-specific (HPV 16 and 18) immunity leaving a small proportion of Zimbabwean women unprotected against other high-risk HPV geno types such as 31, 33 and 58. Future HPV vaccines such as the nanovalent vaccine will be more useful to Zimbabwe as they will protect women against more genotypes.
The electronic version of this article is the complete one and can be found online at: http://www.infectagentscancer.com/content/9/1/16
It is extremely positive that focus is on populations which are suffering the most from cervical cancer – women in developing countries. It is natural that the HPV vaccines are considered. However there is no evidence yet that these vaccines have prevented cervical cancer and the answer to this may not be known for many years. Also, it is thought that HPV infection alone is not the cause of cervical cancer and that an additional element is necessary for this to occur.
The authors of the study mention a few challenges regarding introduction of HPV vaccines, for instance the target population and the type-specific strains in the vaccines. However, there are many more challenges which should be considered. These include:
Safety
The vaccines show an extremely high incidence of serious adverse reactions and many deaths (VAERS); there is concern across the world – and there are already signs – that the vaccines may increase risk of for example infertility, brain damage, cancers and a wide range of autoimmune conditions which may present symptoms up to years after vaccinations.
Reports from VAERS show that a relatively higher percentage of serious adverse reactions are caused by HPV vaccines than by other vaccines.
CANCER
It is worrying that symptoms of cervical cancer are presented by young girls when this was previously almost unknown at a young age.
The vaccines have not been tested for carcinogenicity.
Recombinant HPV DNA has been discovered in Gardasil, tightly bound to aluminium and has a conformation the consequences of which are unknown and which may indeed be horrific. It is certainly feared that the risk of autoimmune conditions and cancers may be increased.
The strains removed by the vaccines will be replaced by new strains as nature never leaves a void. It is not known whether the new strains are more carcinogenic than the ones which are replaced.
In other words, the vaccines may actually increase risk of cancers.
CONGENITAL ANOMALIES
Questions have been posed concerning the possibility of babies being born with deformities when the mothers have been vaccinated with HPV vaccines during pregnancy, but satisfactory responses have not been received from the authorities.
FEMALE GENITAL MUTATION
This is known to take place in Zimbabwe, although the extent is unknown. Mutilation leads to infections and the microbial flora in the infections may be more varied and even differ considerably between individuals.
In many cases the vaccines may not target the right strains and the vaccines may in fact be useless.
It is thought that HPV infection alone is not the cause of cervical cancer and that an additional element is necessary for this to occur.
WHAT PRICE WILL BE PAID?
The cost to be paid may indeed be very high. In addition to the vaccines it includes the unknown price of suffering due to potential serious adverse reactions.
Considerable investment in educational campaigns concerning for example the dangers of smoking and of female genital mutilation, campaigns focusing on sexual education, use of condoms, etc, may reduce the incidence of cervical cancer. In any case, such information campaigns may well contribute more towards improved health in general than the HPV vaccines, which are known to cause serious adverse reactions including deaths.