Research reveals gaps in adult pertussis vaccination

New research^1* highlights that older Australians may be missing out on protection against pertussis (whooping cough) because GPs tend to focus on vaccinating those in close contact with young children, rather than considering the risk and impact to adults themselves.

Surveys involving more than 400 GPs and more than 6500 patients were conducted in four waves between 2014 and 2018, showing that discussions relating to adult vaccination only occur in a minority (<10%) of GP encounters.

When adult vaccination was discussed, only just over half of GPs spontaneously recalled discussing pertussis vaccination. They were twice as likely to recommend pertussis vaccination for grandparents compared with adults of a similar age who were not in contact with children. This suggests that pertussis may be misconceived as a childhood disease and that the risk to older adults themselves is not well understood.

GPs have a key role to play in increasing adult vaccination coverage for pertussis with their recommendation. The study found that when GPs did proactively discuss vaccines, about 73% of adults would proceed to be vaccinated and a recommendation from a GP is a strong predictor for an adult to receive a pertussis vaccine.

According to study co-author Associate Professor Michael Nissen, Director of Scientific Affairs and Public Health at GSK Greater China Intercontinental (GCI), the results are concerning given that, according to an AIHW report, as few as one in nine people have received a pertussis vaccine in adolescence or adulthood.²

“Despite evidence of disease burden from pertussis in adults and correlations between older age and hospitalisation rates from the disease, we still have relatively low immunisation rates in adulthood for pertussis. The drivers seem to be low awareness and low GP recommendation for adult vaccination. We definitely have two key factors to work on there,” Professor Nissen said.

Unvaccinated adults identified a lack of GP recommendation (52%) and lack of awareness of the need for adult vaccination (26%) as the two top reasons for not being vaccinated.

Dr Rodney Pearce, Chairman of the Immunisation Coalition (formerly the Influenza Specialist Group), said that protection of our older population has come into sharp focus in recent times.

“People aged over 65 are at increased risk of complications if they contract pertussis. So as per the current guidelines from the Australian Technical Advisory Group on Immunisation (ATAGI), healthcare professionals need to be framing their recommendations around the health of older adults, independent of contact with young children,” Dr Pearce said.

“It has been shown through COVID-19 that older adults have lower immunity and higher vulnerability to infectious diseases such as pertussis.^3–5 GPs are uniquely placed to increase vaccination coverage via their advice to patients about pertussis at a time when many older adults are feeling particularly vulnerable,” Dr Pearce concluded.

Professor Mary-Louise McLaws, Professor of Epidemiology in Healthcare Infection and Infectious Diseases Control at UNSW, is one who can attest to the importance of pertussis prevention from a personal perspective.

“When I say that protecting adults from diseases that are vaccine-preventable is important, I’m not just talking as a professional epidemiologist but also as someone with a personal experience of pertussis. I was diagnosed with pertussis as an adult,” Professor McLaws said.

“The cough is insidious. It becomes more and more persistent, gets worse at night and hangs around for weeks. It stayed with me for three months.”

References

1. Bayliss J, Randhawa R, Oh K, Kandeil W, Jenkins V A, Turriani E, Nissen M. Perceptions of vaccine preventable diseases in Australian healthcare: focus on pertussis. Human Vaccines & Immunotherapeutics. 2020. https://doi.org/10.1080/21645515.2020.1780848
2. Australian Institute of Health and Welfare (AIHW). 2009 adult vaccination survey: summary results. Canberra, ACT, Australia: AIHW; 2011. Cat. no. PHE 135.
3. Kandeil W, Atanasov P, Avramioti D, et al. The burden of pertussis in older adults: what is the role of vaccination? A systematic literature review. Expert review of vaccines. 2019;18(5):439-455.
4. Doherty TM, Del Giudice G, Maggi S. Adult vaccination as part of a healthy lifestyle: moving from medical intervention to health promotion. Annals of medicine. 2019;51(2):128-140.
5. Johns Hopkins Health. Coronavirus and COVID-19: Caregiving for the Elderly. https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-caregiving-for-the-elderly. 2020. Accessed April 2020.

*The research was sponsored by GSK.

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