Cells of Fall Armyworm used to produce proteins for Flu Vaccines
Influenza is primarily a bird virus and will grow in chicken eggs. Traditional vaccines are produced by injecting the virus into chicken eggs and making a vaccine from “killed” virus or the virus hemagglutinin (the part of the virus that is recognized by the human immune system). Egg produced virus can sometimes contain trace contaminants of egg protein which can cause an allergic reaction is people with egg allergies.
In insect cell vaccines, an insect specific virus is used to infect insect cells in culture. The insect specific virus is genetically modified with a gene for the influenza hemagglutinin. An infected insect cell will produce an overabundance of hemagglutinin protein. The hemagglutinin is purified and forms the basis of the vaccine. The vaccine is “egg free” and safe for use by people with egg allergy. Estimates are that Flublok (produced in insect cells) is 45% effective against all strains a flu. Insect cells offer the prospect of more rapid production of large amounts of vaccine at lower cost.
Living With Insects Blog 
What about the people who are not allergic to eggs, but are allergic to insects like dust mites and roaches? And how is the ‘hemagglutinin purified” ?? I do not have complete confidence that these new uses for GMO’s are tested long and thoroughly enough. Especially given the final sentence of the article: “Insect cells offer the prospect of more rapid production of large amounts of vaccine at lower cost.” Do things quickly and at a lower cost <— This is like the motto of all the companies that are creating and pushing the GMO's into the marketplace. I do not have confidence in this new way of creating our vaccine's. I think I would rather take my chances with getting the flu.
Allergies to dust mites and roaches are due to proteins that are not produced by all insects and not produced by the Sf9 cells. The antigenic protein produced by the insect cell method can be purified to a high level so that potential allergen, if any would be at such low levels an effect would be unlikely.
There is a much greater risk of susceptible individuals dying from influenza than for all vaccines combined. Flu mortality data is collected and reported by CDC in Flu Weekly ( http://www.cdc.gov/flu/weekly/ ), but not hyped by the media. Most people do not see the mortality information. For example, in the last data release (Feb 7, 2015) 92 infants and children died of flu.
Of course, nothing is free of risk. This is why scientist do not talk about safety but about risk. (Is crossing a street safe? There is always some risk however small. but that risk can be quantified.) Whether or not a risk is acceptable is a value judgement of individuals when the risk only impacts the individual. Individual behaviors can pose unacceptable risk to the general public (speeding in a heavy pedestrian area; unvaccinated people spreading disease to others). The public may sometimes act for its protection against individuals who create unacceptable risks especially to public health and disease prevention, whether it is lack of vaccination or dumping raw sewage in surface water.