Vaccination rates for adult vaccines included in the NIP are less well documented and generally considered to be much lower than they are for childhood vaccines. Of the estimated 4.1 million undervaccinated people in Australia each year (those who are eligible for vaccines under the NIP but do not receive them), approximately 3.8 million (92%) are adults (Figure 1).1 The most recent Adult Vaccination Survey, conducted more than eight years ago in 2009, reported that 74.6% of Australians aged 65 years or older had received the seasonal influenza vaccine and 54.4% had been vaccinated against pneumococcal disease. In comparison, over 92% of children in Australia are fully immunised.11,12 More recently, a Newspoll Omnibus Flu Vaccination Survey in 2014 reported that only 39% of all adults and 63% of at-risk adults received the influenza vaccine.13 Factors affecting poor vaccination coverage in adults are listed in Box 1.14,15
Opportunities to discuss vaccines
Immunisation status should be considered part of routine consultation with adults in general practice, just as it is for children. Every visit to general practice should be viewed as an opportunity to discuss immunisation status (Figure 2).
The immunisation HALO
Vaccine recommendations for individuals differ depending on their risk factors. A useful guide when assessing adult vaccination needs is the ‘HALO’ principle, which considers the risk factors of Health, Age, Lifestyle and Occupation.4 Examples of how this can be applied are given in Box 2.4,16-18 A pre-vaccination health screen is recommended for all persons to be vaccinated. An example of a pre-vaccination screening checklist is available in the Handbook, along with the recommended responses to conditions or circumstances identified using this checklist (see the Resources box, Box 3).4
Recommendations for adult immunisation
Vaccinations recommended for adults are discussed in detail in the Handbook, and summarised in the National Centre for Immunisation Research and Surveillance (NCIRS) ‘Immunisation recommendations for adults in Australia’ and more briefly in the Table.4-6 Helpful resources are outlined in Box 3.
The Australian Government funds vaccines listed on the NIP.6 This schedule, implemented by the Government’s Immunise Australia Program, currently includes vaccines to prevent 16 infectious diseases for people in specified age or risk groups, of which there are four vaccine-preventable diseases targeted for prevention in adults (influenza, pneumococcal disease, pertussis and herpes zoster). Other vaccines recommended by the Handbook are funded by some state or territory health departments and some workplaces or are available for purchase privately.
A single dose of live attenuated herpes zoster vaccine is recommended for all adults 60 years and older to prevent shingles and postherpetic neuralgia. Since November 2016, the vaccine has been included in the NIP for all adults at 70 years of age, with a catch-up program for those aged 71 to 79 years until October 2021. People aged 70 years and older have a higher risk of disease than younger people and on balance vaccination in the age group 70 to 79 years is the most cost-effective in terms of population-level use of the vaccine.19 The zoster vaccine is, however, contraindicated in people who are immunosuppressed due to either a medical condition (including leukaemia, lymphoma and untreated HIV infection) or medical treatment (including but not limited to most biological immunosuppressives and immunomodulators, with the exception of certain short-term or low-dose corticosteroids and other drugs, as listed in the Handbook).4
The zoster vaccine is formulated from the same varicella–zoster virus strain as the childhood varicella (chickenpox) vaccine but is of higher potency, containing approximately 14 times the concentration of live attenuated virus. Guidance for its use is available both in the Handbook and the NCIRS online fact sheet ‘Zoster vaccine for Australian adults’ (Box 3).4
Pertussis and tetanus
Pertussis vaccination using the low-dose (reduced diphtheria toxoid and pertussis antigen content) diphtheria–tetanus–acellular pertussis vaccine (dTpa) is recommended and funded by states and territories for women in their third trimester of every pregnancy (ideally between 28 and 32 weeks gestation) to provide optimal protection to the newborn via the transfer of antibodies in utero. Vaccination at least seven days before delivery has been shown to prevent pertussis in 91% of infants under 3 months of age.20 Women who do not receive pertussis vaccine while pregnant should be given it as soon as possible after giving birth. Any adult household contacts and carers of infants aged less than 6 months are recommended to have a dTpa vaccine at least two weeks before having close contact with the infant, or a booster dose if 10 years have elapsed since their previous dose.
A single dTpa booster dose is recommended for adults aged over 65 years if they have not received one in the previous 10 years. Healthcare workers are also required to receive a booster dose of dTpa vaccine every 10 years. Although there have been cases of ‘breakthrough pertussis’ in persons within 10 years after vaccination, this is still considered the most practicable interval for a routine recommendation. Further details on pertussis vaccines are available in the NCIRS online fact sheet ‘Pertussis vaccines for Australians’ (Box 3).