A BREAKTHROUGH FOR WOMEN’S HEALTH
Canada’s best medical and scientific minds have been working non-stop to create an effective and practical new vaccine for Genital Human Papillomavirus (HPV). The most recently developed vaccine should be seen as a major breakthrough for women’s health.
Significant improvements
HPV, which is the most common form of STI, can, if left untreated, lead to genital warts, recurrent respiratory papillomatosis (RRP) and, most seriously, cervical cancer.
“The previous, quadrivalent vaccine only worked against four strains of HPV, but this new vaccine, the nanovalent, protects against nine strains,” explains Obstetrician and Gynaecologist, Dr. Denise Black. “In theory, this gives the vaccine efficacy against cervical cancer up around the 90 to 95 percent range.”
This vaccination efficacy rate is a significant improvement on the current vaccine, which prevents cervical cancer developing in up to 70 percent of HPV cases, explains Gynaecologist, Dr. Céline Bouchard.
“The new vaccine will also decrease cases of pre-cancerous lesions in the cervix by between 75 and 85 percent,” says Dr. Bouchard. “This, ultimately, results in women needing less gynaecological treatment, which is a good thing because that sort of treatment has consequences for women, such as premature labour and premature rupture of membranes.”
Embracing innovation
The development of the new vaccine has only been made possible by the eagerness of leading medical scientists to pursue and embrace innovations in research and technology.
By examining the previous vaccination closely and, at the same time, investigating the next most common strains of HPV that cause cervical cancer, scientists were able to target five strains that they wanted to vaccinate against.It’s the addition of these five strains into the vaccine that gives such a high rate of immunity efficacy.
“The new vaccine is a very important advance in women’s health,” says Dr. Bouchard. “This sort of prevention is, for us, a huge step forward because without effective vaccination and screening strategies there would be lots of cases of cervical cancer, as seen in low resources countries where cervical cancer is a major cause of women’s deaths.”
Know the facts
Dr. Black feels that it’s important for people to realize that no virus is injected into your body when you’re given the vaccine: at no point will you ever be injected with HPV. “All that’s used is a piece of protein from the viral capsule, which is then mixed with the vaccine’s adjuvant,” she explains. “That induces your body to recognize that this protein is foreign and, in turn, your body produces an antibody response to it.”
This vaccine uses recombinant DNA technology to produce “Viral Like Particles” (VLPs), which allow expression of major capsid L1 antigen. This technology allows the L1 antigen to then self assemble a highly immunogenic but non-infectious VLP. The VLP lacks the infectious viral genome, but is able to elicit a very powerful type-specific production of neutralizing antibody.
The antibody response is known as phase one of the vaccine. Phase two, which is more important for longerterm immunity, works when the protein from the viral capsule goes into your B cells’ memory. “So, if your body contracts an HPV infection, it’ll be recognized when the memory of the B cells is activated, and that will then cause production of an immune response,” says Dr. Black.
Cases of cervical cancer in Canada are decreasing and overtime the new vaccine will help the rate of incidence fall even further. Although, due to the very slow growing nature of cervical cancer, it may be 20 years before we see a decline that can be directly attributed to this new vaccine. The progression from normal to cancer follows fairly predictable pre-cancerous changes, and what we’re seeing already is a decline in the number of pre-cancerous lesions among the group of women who have already been vaccinated.
Get protected
There is a common belief among Canadians that vaccinations for HPV are only of value for young girls who have not yet become sexually active, but, says Dr. Black, this attitude is incorrect and damaging and needs to be eradicated.
“Yes, vaccinating people before they become sexually active is optimal for protection, but any woman that is in a situation of risk should know about the vaccine and should strongly consider getting it,” says Dr. Black. “We seem to be missing that point of the message; it’s never too late to get vaccinated.”
The statistics surrounding HPV prevalence should act as a reminder for all women about the importance of getting a HPV vaccine. Before the introduction of HPV vaccines, a Canadian woman had an 80 percent chance of contracting HPV over the course of her lifetime.It’s frustrating for physicians that some women are reluctant to take the decision to get vaccinated, even when the evidence clearly states what a step forward this is for women’s health.
“Women of any age should not be shy about getting the vaccine: it’s normal to have sexuality, it’s a part of humanity,” says Dr. Bouchard. “Cervical cancer is now the only cancer that is totally secondary to the viral infection; the only cancer that is completely preventable, and this new vaccine has an important part to play in that prevention.”