Doctors topped the list for getting the flu vaccine last year with the call going out once more for health care workers to get the annual jab to help protect vulnerable patients.
The United States’ CDC (Centers for Disease Control and Prevention) reported late last week (Feb 8) that levels of influenza-like-illness (ILI) had reached the peak of the 2009 H1N1 pandemic with unusually high numbers of hospitalisations in the 50-65 age group.
CDC reported that it didn’t believe the flu season had peaked in the US yet but the United Kingdom’s Public Health Service at the same time reported that flu numbers had stabilised and at this stage didn’t seem as severe as some other recent seasons. Both countries reported that the main flu strains circulating were flu A(H3N2) plus H1N1 strains and flu B strains.
The Immunisation Advisory Committee (IMAC) and Ministry of Health is also reminding healthcare workers that they can transmit influenza without knowing they are infected as the flu doesn’t always cause symptoms or make people unwell.
Last year 66 per cent of district health board employees received the influenza vaccine – up on 61 per cent in 2014. Doctors remain the profession with the highest uptake of the flu vaccine with 72 per cent receiving the jab last year but nurses are now not far behind having increased their uptake from 59 per cent in 2014 to 68 per cent last year.
Midwives remain the profession with the lowest uptake which fell from a high of 59 per cent in 2015 to 54 per cent last flu season. Allied staff uptake also fell from a high of 65 per cent in 2015 to 61 per cent last year. The DHB ‘other employees’ category also fell slightly to 63 per cent.
Data from the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) study, based in Auckland, suggest that four out of five children and adults (80%) with flu were asymptomatic. And an earlier study – following the 2009 ‘swine flu’ pandemic in New Zealand – found almost one quarter of the adults who reported that they had not had influenza in 2009 were tested and found to have been infected by the H1N1 virus that caused the pandemic.
The SHIVERS study has also indicated that flu vaccine effectiveness in New Zealand is around 50 per cent or more.
Four strain vaccine available this year
Pharmac has confirmed that this year it will be funding for the first time a flu vaccine targeted at four strains of the flu virus rather than the usual three strains.
Two forms of quadrivalent vaccine will be funded from March 1 with Influvac Tetra funded for eligible people aged three years and over and another vaccine, Fluarix Tetra, funded for eligible children aged 6 to 35 months.
Pharmac deputy medical director Dr Bryan Betty says the four-strain vaccine will offer additional protection against influenza in 2018, and into the future.
Pharmac negotiated long-term supply with Mylan in 2016, including provision for a four-strain vaccine once it was approved for use by Medsafe. This has now occurred.
The funded vaccines will both contain the strains of influenza virus specified by the World Health Organisation for the 2018 Southern Hemisphere influenza season which are:
- an A/Michigan/45/2015 (H1N1)pdm09-like virus;
- an A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus; and
- a B/Phuket/3073/2013-like virus
- a B/Brisbane/60/2008-like virus
CDC Acting Director Dr. Anne Schuchat said last week that it was known that flu vaccines can often have lower effectiveness against H3N2 viruses but added that “however some protection is better than none” against the virus strains which were often linked to more severe illness – especially among children and people aged 65 and older.
Stock of the seasonal influenza vaccine is typically available from early March until 31 December each year.
The exact start date for the 2018 seasonal influenza vaccination programme will be notified by the Ministry of Health in due course. The Fluarix Tetra vaccine for children under 3 years is likely to be available from mid-April 2018.
NB This article was updated at 1pm on February 15 to included the CDC/PHE information and more details on the strains covered by the vaccine.