I understand your dilemma.  You are right, in a way, that your older son and daughter should receive the vaccine before your twelve-year-old.  However, even though she seems to be too young for you to consider her sexuality, she should receive the vaccine now instead of later.  Let me explain in more detail about this.

Human Papilloma Virus (HPV) is one of the most common virus that infects us.  There are over 100 genetically distinct types of HPV.  You are likely familiar with warts on the hands and feet; they are caused by HPV.  HPV infects the skin as well as mucus membranes (these are surfaces that cover the inside of our body, including the mouth and throat, as well as our genitalia and intestinal tract).  HPV spreads from person to person, mainly by direct contact.

There are about 40 strains of HPV that can infect our genitalia.  These infections occur not only during intercourse, but also by sexual touching.  Most of the infections go unnoticed because there is nothing that anyone can see.  Sometimes the infection can appear as warts on the penis, the vulva, or around the anus, which can lead to much anxiety and shame.  When the infection is in the vagina and the cervix, it can be totally silent until an internal examination is done, or until vaginal or cervical cancer has developed and has spread to other parts of the body.

HPV is responsible for almost all cancers of the anus, the penis, as well as the vulva, the vagina, and the cervix.  However, not all the HPV strains can cause cancer; actually a relatively small number of them are responsible for these cancers.  The remaining HPV infections produce warts around the genitalia and the anus.

In the year 2002, 1350 Canadian women were found to have cervical cancer, and 390 died from this illness.  This may not sound like a lot of people, but the tragedy of this disease is much more than statistics.  Many of these are young women who will never see their children growing up.  It is devastating for their families and friends.

There are very few cancers that are definitely caused by virus.  HPV is unique in this way.  It is true that the majority of people infected with HPV will get rid of the virus after several years.  The trouble is that they can spread the virus to others while they are still infected, and we have no way of knowing who will have persistent infection, and who will ultimately develop cancer.

What we do know, through research, is that between 11% to 29% of Canadians are infected with strains of HPV that are spread through sexual contact.  Most of these are in young people under 25 years of age.  The highest chance of getting HPV infection is within 5 years after beginning sexual activity.  The chance of infection increases in those who begin to have sex early, those who have multiple sexual partners, as well as those who don’t use condom for protection.  However, use of condom does not completely prevent HPV infection.

Health Canada recently approved the first HPV vaccine for females between 9 to 26 years of age.  There are four strains of HPV that this vaccine can protect.  Two of them, types 16 and 18, are responsible for around 80% of cervical cancers in North America.  The other two, types 6 and 11, cause most of the warts in the genital area.  By combining these four strains of HPV, it can prevent the majority of infections in the genital and anal areas which can lead to warts and cancers.

In order for the vaccine to work, it has to be given before these infections occur.  The best time is before any kind of sexual activity.  Research has shown that in North America, 1% to 4% of children have had intercourse by grade 6.  The rates gradually increase with age so that by grade 11, or 16 years of age, 40% to 46% of adolescents are sexually active.  It is important to remember that sexual touching can cause HPV infection.  Sexual touching and exploration often precedes intercourse by some time, although there is no data by how long.  Therefore, it is important to protect children early, even though parents don’t believe that they are sexually active.

There are many factors that determine when the vaccine should be given.  This vaccine has been proven to be safe and effective for girls as young as 9 years of age.  Most of these children would be in grades 3 or 4.  As a result, some provinces have decided to vaccinate girls at grades 6 or 7, when many schools are beginning to provide sex education to the students.

Although this vaccine was approved recently, extensive research was done before it was approved.  HPV is a very difficult virus to grow in the laboratory.  As a result, some parts of the virus was isolated and produced artificially in the laboratory using a tool called recombinant technology.  There is no complete virus in the vaccine; therefore, there is no chance that anyone can get infected with HPV through immunization.

You may wonder how safe is this vaccine.  Although this is a new vaccine, the recombinant technology that produced it is not new at all.  Hepatitis B vaccine has been used in North America for around 20 years.  It is produced by the same technology, and the vaccine has been proven to be extremely effective and safe.

At the present time, there is data showing that the HPV vaccine can stimulate antibodies in both boys and girls, but we don’t have all the data to show that it is effective in boys also.  My own prediction is that it is just as effective in boys as in girls.  As a result, this vaccine is not approved for boys, and our government is not vaccinating boys as yet.  It would make sense, as you said, that we should vaccinate boys also, since they are the other half of sexual contact in heterosexual activity, and infections occur just as easily among homosexuals.  Actually some countries are vaccinating both boys and girls at the same time.