Flu vaccination: Now or later, which is best?
Much has been written over the past couple of days in regards to the timing of this year’s flu vaccinations, with the Australian Medical Association (AMA) ‘urging people to hold off getting this year’s flu vaccine’ and voicing concerns that some pharmacy groups are offering their vaccination programs too early.
But is the evidence clear on this? Not entirely, according to Professor Robert Booy, an Infectious Diseases Paediatrician and Head of Clinical Research at the National Centre for Immunisation Research and Surveillance (NCIRS) in Sydney. He believes that ‘pharmacists are not risking the efficacy of the immunisation program by offering flu vaccination in March’, if these are given to ‘healthy adults’.
There are only a few studies showing some decline in vaccine effectiveness 3 - 4 months following vaccination, but there are also a number of limitations to these studies in their design and analytical methods and it is uncertain if or how the decline of vaccine effectiveness may differ by age group. Prof Booy indicated that it is advisable for those people aged over 65 years or with chronic diseases to wait until April or early May in order to ensure better protection for the height of the season (July with a peak in August). At which time the 2 higher-immunogenicity trivalent influenza vaccines (TIVs), Fluzone High-Dose and Fluad, will be funded by the National Immunisation program. These vaccines offer potentially higher protective effectiveness, especially against influenza A/H3N2, which is more common and severe in the elderly.
All parties do agree however that annual flu vaccination remains the best strategy for preventing influenza in older persons (aged ≥65 years) and in those with increased risk of severe disease due to underlying medical conditions. Also, in order to create a protective herd immunity and reduce absenteeism/presenteeism in the workplace, it is recommended for healthy, younger individuals.
Importantly those who have special needs, such as pregnant women, people travelling to regions with high influenza activity or those who are likely to miss out on vaccination otherwise should be vaccinated in a timely manner.