The protection provided by acellular pertussis vaccination wanes rapidly, and full protection lasts on average up to five years. Similarly, pertussis infection does not provide lifelong immunity. Most older people are susceptible to pertussis, and data increasingly show that infection can have severe consequences in this age group.10 Recent evidence shows that pertussis-associated deaths occur in older people as well as the very young.10 Because of the increase in morbidity associated with pertussis in older people, they are recommended to have a single booster dose of dTpa, which is the only adult pertussis vaccine available, if they have not received this vaccine in the past 10 years.11-13
Vaccination is also supported for older people who intend to have close contact with infants (younger than 6 months), to prevent pertussis transmission in the period before the infants are fully protected by direct immunisation (see the case study in Box 1 and Special risk scenarios, below). However, increasing vaccination of pregnant women may soon reduce this need.
An opportune time for pertussis vaccination is at the time of tetanus vaccination, using dTpa. Reviewing the pertussis vaccination status of all people when they turn 65 years of age will protect them and reduce circulation in the community.
Meningococcus (Neisseria meningitidis) strain W has emerged as the predominant meningococcus strain in Australia, surpassing strain B in 2016.14,15 Strain W is a hypervirulent strain associated with a higher risk of invasive disease and mortality. In 2017, adults aged over 65 years accounted for 25% (24/94) of the total cases reported in Australia. Two meningococcal vaccines, a quadrivalent meningococcal conjugate vaccine covering strains A, C, W and Y and a meningococcal B vaccine, are available for adults through private prescription.
Meningococcal vaccination is recommended for adults with immunodeficiency, including those who have had a splenectomy and those with HIV infection, if they are a close contact of a person with meningococcal infection, and those taking the medication eculizumab.16 It is not known whether patients taking other types of monoclonal antibodies are at increased risk of meningococcal disease. In 2017, the state of Victoria funded meningococcal vaccine for all gay and bisexual men and men who have sex with men, at any age.17 In areas with regional outbreaks in any age group, vaccination against the prevalent strains should be offered to older people irrespective of additional risk factors.
Vaccination against Haemophilus influenzae type b (Hib) is recommended for infants, children and some people who are immunocompromised. This includes patients who have undergone splenectomy and were not vaccinated in infancy or were incompletely vaccinated, functional and autologous haematopoietic stem cell transplant recipients and all solid organ transplant recipients.18
Special risk scenarios
People with reduced immune function
Although older age itself is associated with a reduction in most immune functions, in some people other conditions further reduce immune competency. In people who are immunocompromised, vaccination with a live vaccine (e.g. the live attenuated herpes zoster vaccine) is less safe, and response to vaccination with most other vaccines is reduced.
The live attenuated herpes zoster vaccine can be safely given to about 97% of older people. This includes those using corticosteroids in the following categories: those taking oral prednisolone at a dose less than 20 mg for less than two weeks; those using inhaled or topical corticosteroids; and those taking corticosteroids as replacement therapy. More detailed recommendations on whether a person is immunocompromised to the extent that they should not receive this vaccine have been recently published.19
Recommendations on vaccination for people about to become immunocompromised (e.g. by elective splenectomy or by taking higher-dose immunosuppressants) can be broadly summarised as: check current vaccination status and give any outstanding vaccines. More detailed advice for people about to undergo splenectomy are available from Spleen Australia (https://spleen.org.au).20
Grandparents and other older people exposed to children
Infants younger than 6 months, who are too young to have received a full course of pertussis vaccine, are at risk of being infected with pertussis, typically by an older relative such as a grandparent or great-grandparent. Pertussis vaccination should be offered to older people before contact with infants younger than 6 months. Increasing immunisation of pregnant women to protect their infants through passive immunity via the placenta may affect this recommendation.
No other additional vaccinations are recommended for older people in contact with younger people. Indeed, it is likely that protection works the other way – vaccination of younger people with conjugated pneumococcal vaccine and influenza vaccine protects older people through herd immunity.