What’s the latest information from the experts
Here are 10 top points on what to know about influenza this year, according to experts from Westmead Hospital in Sydney, the University of Sydney and NSW Health Pathology, as published in Australian Prescriber – a publication of NPS MedicineWise.
1. Routine vaccination is the most important intervention for preventing influenza-related illness and severe complications. Quadrivalent influenza vaccination is recommended annually for adults and children aged six months to 64 years. High-dose or adjuvanted trivalent vaccines are recommended annually for people 65 years and over.
2. Hand hygiene, cough etiquette and voluntary home isolation are also important factors in reducing transmission.
3. Influenza in pregnancy is associated with an increased risk of maternal morbidity and mortality, along with preterm delivery. The influenza vaccine can be administered at any stage of pregnancy.
4. It is particularly important that healthcare providers in hospitals and general practices are vaccinated, given their likely exposure to individuals with influenza.
5. The antibody response to the vaccine takes approximately two weeks, with a period of optimal vaccine efficacy of around four months post vaccination. In Australia the seasonal influenza vaccine becomes available in March or April, and this is an appropriate time to vaccinate.
6. Vaccine efficacy is variable from year to year and in different populations.
7. The standard influenza vaccination for children and adults, including pregnant women, is now a single quadrivalent preparation. An exception to this is children aged six months to nine years who are receiving the vaccine for the first time, and those in the first year after receiving a solid organ or haematopoietic stem cell transplant. These patients should receive two doses at least four weeks apart to induce an optimal immune response.
8. Neuraminidase inhibitors are the mainstay of antiviral therapy against influenza. However, they need to be started within 48 hours of symptom onset and are most effective within 24 hours.
9. Prompt commencement of neuraminidase inhibitors is recommended for patients with confirmed or suspected influenza who require hospitalisation, or are at risk of complications. The recommended duration of therapy (oseltamivir and zanamivir) is five days.
10. There is a role for neuraminidase inhibitors in prophylaxis. Oseltamivir and zanamivir are approved in Australia for this and have shown to significantly reduce the risk of symptomatic influenza. However, chemoprophylaxis should not be considered as an alternative to vaccination.