Quadrivalent Influenza Vaccine (Flublok®)

Produced as quadrivalent recombinant influenza vaccine, Flublok® is considered to be the next generation of influenza immunization, and is classified as the competent seasonal influenza vaccination for the 2021/2022 season in Hong Kong. Any individual aged 18 years or above will be eligible for taking the quadrivalent vaccine, and it could yield better protection than the traditional influenza vaccines. Comparing to the standard quadrivalent inactivated influenza vaccine, it is proven to be 30% more effective in preventing flu for the population aged 50 years or above, and the hemagglutinin (HA) antigen per strain is triple to the ordinary vaccine as well. Apart from that, the new vaccine can offer 40% additional cross-protection than standard vaccine, i.e. can still offer protection to the recipients towards virus strains other than those specified in vaccine.
Product Code: V-FBS Flublok
i h

What is the discrepancy in between quadrivalent recombinant influenza vaccine and standard quadrivalent inactivated influenza vaccine?

Flublok® is produced by recombinant technology, and does not require any egg or influenza virus in the production process. Meanwhile, the traditional influenza vaccine contains inactivated viruses and ovalbumin (an egg protein), and yet the content should be lower throughout repeated purification in the manufacturing procedures. Both vaccines are received by injections, and in general, it will take 2 weeks for the production of antibody to protect against influenza.

Why is it necessary to receive the Flublok®?

Under the pandemic, the mortality rate of the patients who get infected by COVID-19 and influenza will be 6 times higher than those uninfected. It is advised by World Health Organization (WHO) that influenza immunization should be taken every year to avoid infection, and could also lower the risk of heart attack. Flublok® is approved by USA FDA in 2017, and is a non-egg-based vaccine, thus any person suffering from egg allergy can receive the vaccine.

What is the composition of quadrivalent recombinant influenza vaccine?

The quadrivalent recombinant influenza vaccine advised by the Centre for Health Protection for the 2021-22 season contains the following components:

  • an A/Wisconsin/588/2019 (H1N1)pdm09-like virus
  • an A/Cambodia/e0826360/2020 (H3N2)-like virus
  • a B/Washington/02/2019-like virus
  • a B/Phuket/3073/2013-like virus