The H3N2, influenza virus generally known as Aussie flu, has widespread in the UK from past few months. The US is also in the grip of this virus currently. In January, the highest number of people have died from this flu in UK and Wales. However, WHO or CDC did not take a notable step against this illness.

It was the frequently asked on Quora, that why doesn’t the CDC or WHO offer more seasonal flu candidate vaccine viruses (CVVs)? An Immunologist has given the answer to this question, that it takes a long duration to grow the vaccine to make a flu shot.

The period for the annual seasonal flu vaccines starts in February, WHO is an organization which coordinates with Global Influenza Surveillance and Response System (GISRS), which is a part of National Influenza Centers (NICs). These organizations are studying the virus in labs of WHO Influenza Collaborating Centers and several Regulatory labs.

The NICs groups isolate the viruses circulating in their regions and submit them to CCs that assist to conduct and analyze the influenza A and B subtypes. WHO refers the influenza A and B vaccines globally also guide to the national public health and regulatory authorities towards a vaccine and which need to be adaptable to the local epidemiological state in each region. Circulating influenza viruses continue to evolve and update regularly, henceforth influenza vaccines are evaluated and updated.

Other methods to produce seasonal flu vaccines such as cell-based, recombinant protein-based, and plant-based. However, the major drawback in the production of egg-based flu vaccine a longer duration, inadequate or threated epidemics. Lack of knowledge regarding an effective and specific immune response to flu can affect flu vaccines. Different studies feature flu correlates to immunity or protection is subject to debate.

Reasons behind this delay to action by WHO and CDC include a prolonged length and high expense for each approach that can pass the benchmark for safety and efficacy. Whereas the approaches are not yet close to the finish line.