Articles

Vaccine Recommendation

Ausvax recommends the trivalent flu vaccine in 2016

Quadrivalent vaccines may provide little or no additional protection than that offered by trivalent vaccines [1]

McLean et al 2015, p. 1538

The seasonal influenza vaccine contains three (trivalent vaccine) or four (quadrivalent vaccine) influenza virus strains: two influenza type A virus strains and either one or two influenza type B virus strains.

At Ausvax we provide services in line with the best available evidence and therefore Ausvax is not routinely offering the quadrivalent flu vaccine in 2016 for the following reasons:

  1. The additional type B virus strain in the quadrivalent flu vaccine offers very little extra benefit for adults as influenza B is usually milder than influenza A and primarily affects children rather than adults [2]
  2. While the trivalent flu vaccine only contains one type B virus strain, studies have shown that this strain provides cross-protection against the extra B virus strain contained in the quadrivalent vaccine. This means that the trivalent vaccine will still help to protect your staff against the non-vaccine type B virus even though it is not in the vaccine [1,3]
  3. The second type B virus strain in the 2016 quadrivalent vaccine was also in the 2015 trivalent flu vaccine and your staff who had the flu vaccine or caught influenza B in 2015 are expected to have residual protection against this type B virus strain in 2016 [1,4]
  4. The amount of illness caused by type B virus strains in 2015 was unusually high, has not been seen since 2008 and is very unlikely to occur again for several years. Type B virus strains caused 20% of illness in 2015 compared with an average rate of 8% over the previous four years [5]
  5. The trivalent vaccines that Ausvax uses are expected to be available in early February, whereas the quadrivalent flu vaccine is not expected to be available until much later – possibly as late as the end of May. There is a risk that by opting for the quadrivalent vaccine employers may unnecessarily leave their staff vulnerable to the flu (and especially the more serious influenza A) for longer.

We are aware that the Australian Government has selected the quadrivalent vaccine for their funded vaccine program for vulnerable people – however this program includes children who are at higher risk of influenza B and so will greatly benefit from the use of this vaccine. Furthermore, the Government’s supplier offered the quadrivalent vaccine for the same price as the trivalent vaccine so using the quadrivalent vaccine does not cost more.

Whilst we recommend the trivalent vaccine, there are other reasons why employers would prefer the quadrivalent vaccine. Ausvax is still able to offer the quadrivalent vaccine upon request (additional costs apply).

Ausvax will continue to monitor the trends in illness caused by the flu and amend our advice as more information comes to light. The advice above is intended for the 2016 flu season only as an additional brand of quadrivalent flu vaccine is expected in the Australian market which may result in vaccine price changes and a more favourable assessment of which vaccine we recommend.

  1. McLean, H.Q., et al., Influenza vaccine effectiveness in the United States during 2012-2013: variable protection by age and virus type. The Journal of infectious diseases, 2015. 211(10): p. 1529-1540.
  2. Hamborsky, J., et al., Epidemiology and prevention of vaccine-preventable diseases. Vol. 13th. 2015, Washington D.C. : Public Health Foundation.
  3. Ohmit, S.E., et al., Influenza Vaccine Effectiveness in the 2011–2012 Season: Protection Against Each Circulating Virus and the Effect of Prior Vaccination on Estimates. Clinical Infectious Diseases, 2014. 58(3): p. 319-327.
  4. Lambert, N.D., et al., Understanding the immune response to seasonal influenza vaccination in older adults: a systems biology approach. Expert review of vaccines, 2012. 11(8): p. 985-994.
  5. Australian Department of Health. Australian Influenza Surveillance Report and Activity Updates. 2015 [cited 2015 September 30]; Available from: http://www.health.gov.au/flureport.