House debates

Wednesday, 8 August 2007

National Health Amendment (National HPV Vaccination Program Register) Bill 2007

Second Reading

10:13 am

Photo of Mal WasherMal Washer (Moore, Liberal Party) Share this | Hansard source

The purpose of the National Health Amendment (National HPV Vaccination Program Register) Bill 2007 is to amend the National Health Act 1953 in order to establish and maintain a National Human Papilloma Virus Vaccination Program Register. It also allows for payments to be made to general practitioners for the provision of vaccination information on the register.

Vaccines have had a dramatic effect on the incidence of disease in our populations. According to the World Health Organisation, vaccines are thought to prevent around two million deaths every year. The discovery of vaccines is quite an interesting story, although not always an ethical one. Long before the causes of disease were known and long before the processes of recovery were understood, an interesting thing was observed. If people recovered from a disease, rather than succumbed to it, they appeared to be immune from a second bout of the same illness. It was these types of observations that led the Chinese to try to prevent deadly smallpox by exposing uninfected individuals to material from smallpox lesions. This process, known as variolation, took a variety of forms, from injecting the pus and fluid of lesions under the skin to grinding up dried scabs and inhaling or injecting the ground-up powder. Lady Montagu, wife of the British ambassador, observed this method in the early 1700s and brought it back to England. Although the effects of variolation varied, ranging from causing a mild illness in most individuals to causing death in a few, the mortality and morbidity rates due to smallpox were certainly lower in the populations that used variolation compared with those that did not.

One person who experienced variolation as a child in the late 1700s was Edward Jenner, a young boy who survived the process and grew up to become a country doctor in England. As a country doctor, Jenner noticed that many people who milked cows did not get smallpox, even though they were exposed repeatedly. With this in mind, in 1796 Jenner undertook a daring experiment and infected a young boy with the bovine disease, cowpox, in the hope of preventing subsequent smallpox infection. After allowing the boy to recover fully from cowpox, Jenner unethically infected the boy with smallpox by injecting pus from a smallpox lesion directly into his skin. As Jenner had predicted, the boy did not contract smallpox.

Jenner’s experiment was initially rejected by those in the medical establishment. However, over the ensuing months, he went on to collect case studies and publish a book detailing his observations. As a result, within a few years thousands of people protected themselves from the deadly smallpox disease by intentionally infecting themselves with cowpox. Jenner’s process came to be called ‘vaccination’ after vacca, the Latin word for cow, and the substance used to vaccinate was called a ‘vaccine’.

So how do vaccines work? Disease-causing organisms, such as viruses and bacteria, have at least two distinct effects on the body. The first effect is very obvious—we feel sick and exhibit a range of symptoms. The second effect is less obvious, although it generally leads to eventual recovery from infection—the disease-causing organism induces an immune response in our body. As the response increases in strength over time, the infectious agents are slowly reduced in number until symptoms disappear and recovery is complete.

How does this immune response occur? The disease-causing organisms, such as viruses and bacteria, have proteins called ‘antigens’ which stimulate the immune response. The resulting immune response is multifold and includes a synthesis of proteins called ‘antibodies’. These proteins bind to the disease-causing organisms and lead to their eventual destruction. In addition, memory cells are produced in an immune response. These are cells that remain in the bloodstream, sometimes for life, ready to mount a quick, protected immune response against subsequent infections. If such an infection were to occur, the memory cells would respond so quickly that the resulting immune response can activate the organism, and symptoms would be prevented. This response is often so rapid that infection does not develop.

Obviously a live or virulent organism cannot be used as a vaccine because it would induce the very disease it should prevent. Therefore, the first step in making a vaccine is to separate the two effects of disease-causing organisms. In practice, this means isolating or creating an organism, or part of one, that is unable to cause full-blown disease but that will still retain the antigens responsible for inducing the host’s immune response. This can be done in many ways. One way is to kill the organism using formalin. Vaccines produced this way are called ‘inactivated’ or ‘killed’ vaccines. Examples of killed vaccines in common use today are the typhoid vaccine and the Salk poliomyelitis vaccine. Another way to produce a vaccine is to use only the antigenic part of the disease-causing organism: for example, the capsule, the flagella or part of the protein cell wall. These types of vaccines are called ‘acellular’ vaccines. An example of an acellular vaccine is the Haemophilus influenza B or Hib vaccine. Acellular vaccines exhibit some similarities to killed vaccines. Neither killed nor acellular vaccines generally induce strong immune responses and may therefore require a booster every few years to ensure their continued effectiveness.

A third way of making a vaccine is to attenuate or weaken a live micro-organism by ageing it or altering its growth conditions. Vaccines made in this way are often the most successful vaccines, probably because they multiply in the body, thereby causing a large immune response. Examples of attenuated vaccines are those that protect us against measles, mumps and rubella. Immunity is often lifelong and booster shots are not required.

Some vaccines are made from toxins. In these cases, the toxin is often treated with aluminium or adsorbed onto aluminium salts to decrease its harmful effects. After such treatment the toxin is called a toxoid. Examples of toxoids are the diphtheria and tetanus vaccines. Vaccines made from toxoids often induce low-level immune responses and are, therefore, sometimes administered with an adjuvant—an agent which increases the immune response. For example, the diphtheria and tetanus vaccines are often combined with the pertussis vaccine and administered together. Toxoid vaccines often require a booster every 10 years.

Another way of making a vaccine is to use an organism that is similar to the virulent organism but that does not cause serious disease, such as Jenner did. A more recent example of this type of vaccine is the BCG vaccine used to protect against mycobacterium tuberculosis. The BCG vaccine currently in use is an attenuated strain of mycobacterium bovis and requires boosters every three to four years.

In addition, biotechnology and genetic engineering techniques have been used to produce subunit vaccines—vaccines which use only the parts of an organism which stimulate a strong immune response. To create a subunit vaccine, scientists isolate the gene or genes which code for appropriate subunits from the genome of the infectious agent. This genetic material is placed into bacteria or yeast host cells, which then produce large quantities of subunit molecules by transcribing and translating the inserted foreign DNA. These ‘foreign’ molecules can be isolated, purified and used as a vaccine. The hepatitis B vaccine and the human papilloma virus vaccine Gardasil are examples of this type of vaccine. Gardasil contains the major capsid protein of human papilloma virus types 6, 11, 16 and 18. The proteins are produced separately by the transgenic yeast Saccharomyces cerevisiae. These proteins self-assemble into a virus like particle that is purified and placed into a sterile liquid for injection.

Australia was an early supporter of vaccines. Smallpox vaccination began here in 1804, just five years after Jenner described the protective effect of cowpox, and the vaccine was produced locally from 1847. A vaccine against the plague, Yersinia pestis, developed in 1895, was imported into Australia soon after to control an outbreak in Sydney. The effectiveness of the year-old typhoid vaccine during the Boer War in 1899 led to its production in Australia shortly afterwards.

Since World War II vaccination has had an enormous impact on the lives of Australians. At that time, poliomyelitis and diphtheria struck fear in the heart of every parent, and most families had experienced or knew of a tragedy related to one of these diseases. Also, many children died, were significantly incapacitated by whooping cough or measles, or were born with disabilities as a result of intrauterine infection with rubella. In contrast, in 1998 there were no cases of polio, diphtheria or congenital rubella syndrome reported in Australia and no deaths from measles or whooping cough.

The Commonwealth first provided free vaccines in 1953 with the diphtheria-tetanus-pertussis vaccine. This was followed by the oral polio vaccine in 1966, the rubella vaccine in 1971 and the combined measles-mumps-rubella vaccine in 1989. These have been followed by a range of other vaccines as they have become available. Another major initiative enacted by the Australian government in the area of vaccination was the establishment of the National Immunisation Program in 1997. Under this program the Australian government provides funding to state and territory governments for the purchase of the 25 vaccines listed on the National Vaccine Schedule and funding to Medicare Australia for the Australian Childhood Immunisation Register, the General Practice Immunisation Incentives Scheme and subsidising individual private consultations involving immunisation through the Medicare Benefits Schedule. In 1996 Australian government expenditure on vaccines was $13 million; this grew to $283 million in 2006-07.

In late November 2006 the Australian government added Gardasil to the National Immunisation Program. The reasons for adding this new vaccine to the program were clear. Cervical cancer is the world’s second most common gender-specific cancer amongst women and is currently responsible for the deaths of around 200 women in Australia each year.

Before the introduction of the National Cervical Cancer Screening Program in 1991, the mortality rate was around four in 100,000. It is estimated that the screening program prevents around 70 per cent of squamous cervical cancers and the rate of mortality in 2004 dropped to 1.8 per 100,000 women. The introduction of Gardasil, used in conjunction with the screening program, should reduce this mortality incidence further.

It is essential however that vaccinated girls and women continue to participate in the national screening program. The prophylactic Gardasil vaccine resulted from research by distinguished medical scientist and 2006 Australian of Year, Professor Ian Frazer, and fellow Australian citizen Dr Jian Zhou. Sadly, Dr Zhou’s life was tragically cut short at the age of 42 in 1999, before he could share in the joy of seeing the vaccine brought to market. Not one to rest on his laurels, Professor Frazer is currently working on a therapeutic vaccine for HPV—in other words, to cure the disease. The vaccine could be one of the first products to come out of the new biopharmaceutical production centre. This centre, incidentally, received $100 million in this year’s federal budget.

Gardasil, as mentioned earlier, vaccinates against the human papilloma virus types 16, 18, 6 and 11. Types 16 and 18 are responsible for 70 to 80 per cent of the cervical cancers in Australia and types 6 and 11 cause 90 per cent of genital warts. The human papilloma virus is a common and usually asymptomatic infection. It is highly contagious and many people will acquire an HPV infection within a few weeks of becoming sexually active. In most people the infection clears within 12 to 24 months. However, in three to 10 per cent of women infected with types 16 and 18 the infection does not clear up and can result in cervical abnormalities which in some cases progress to cervical cancer.

Through the National Immunisation Program, the vaccine is being administered to girls aged between 12 and 13 years in three injections over a period of six months through schools which wish to participate. It is the most successful school based program yet, with an uptake of greater than 80 per cent as at the end of June. From this month the vaccine is also available free to girls and women aged up to 26 years through GPs and community providers.

The establishment of a register for the HPV vaccination program is integral to the success of the program. The register will enable: the recording of the details of individuals who participate in the HPV program, allowing statistics on participation rates to be compiled; the recording of vaccination information which can be compared with information recorded in Pap smear, cervical cytology and cervical cancer registers so as to assess the effectiveness of the HPV program over time; the notification of participants of the HPV program, if booster doses are required, to determine vaccination status or to certify completion of the vaccination course; the collection of statistics to inform health authorities, healthcare providers and the public about the HPV program; participants to be informed, or parents of participants, of developments with the HPV program; and the details of vaccination providers to be recorded.

Participants or their parents in the HPV program can opt to have personal details removed from this register at any time. This bill, by enabling such a register, will support the Australian government’s commitment to our progressive, world class immunisation system. I commend the bill to the House.

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