Like master safe-crackers, scientists and researchers worldwide try to dial up the combination to fight one of the most cunning viruses known to man: influenza.
If they are lucky, in any given season, they might get it half right half of the time, according to spot studies by the Centers for Disease Control and Prevention. The flu is an elusive little bug. It adapts. It mutates. It kills — especially the elderly and the very young.
The annual influenza vaccine is formulated from data collected in 113 countries on what strains are making people sick, how much it is spreading and how previous vaccines have worked. Scientists and public health officials then collectively choose the strains to be included in the vaccine.
Health officials say even if it sometimes misses the mark, the flu vaccine keeps people from getting sicker from other strains.
But for it to even work at all, the populace must be inoculated. It’s called herd immunity for reason and the flu will exploit, like any virus, a weakness in that herd. The trouble is the public is skeptical.
“My dad faithfully got his flu shot…. and the flu was the cause of his death. I’ll pass,” said a reader of The Palm Beach Post in the comment section of a story last month about how this year’s flu turned especially deadly in Australia — a harbinger for the U.S. season.
Some scientists say it’s time for a better way to make the flu vaccine, citing their findings at the Scripps Research Institute that the method using chicken eggs to cultivate vaccines may need to be replaced sooner rather than later.
Back to the egg
“The fact we have to struggle so much with it reflects the knowledge that it is a relatively poor and ineffective vaccine,” said Mike Farzan, professor in the Department of Immunology at Scripps Research Institute in Jupiter. “We have to get one every year, not because there is a mismatch, but because it is not a particularly effective vaccine.”
Farzan’s Scripps colleagues in La Jolla, Calif., came out with a study in October that showed why flu vaccines grown in chicken eggs — done since they were invented by Jonas Salk and Thomas Francis — may be past their prime.
“Any influenza viruses produced in eggs have to adapt to growing in that environment and hence generate mutations to grow better,” said Ian Wilson, a Scripps biologist and one of the authors of the study published in journal Plos Pathogens on Oct. 31. These chicken egg mutations make it less efficient in stopping the disease in humans.
This is especially true of the H3N2 virus that shows a tendency to mutate in chicken eggs. This strain nearly killed Loxahatchee teen Jenny Spell as detailed by The Palm Beach Post in February.
Flu vaccine manufacturers, such as GlaxoSmithKline and Novartis, replicate the virus in chicken eggs and then purify the fluid from the egg to generate vaccines.
“Vaccine producers need to look at this mutation,” Nicholas Wu, another lead author of the Scripps study. “There is a huge need for flu vaccine research.”
The researchers say that other methods available for the production of vaccines need to be explored. In the 1990s, scientists started using cells from mammals to cultivate the influenza virus. According to the Singapore Health Sciences Authority, this method could increase vaccine production and reduce virus mutations.
There is a third and intriguing way to produce flu vaccines that the Food and Drug Administration approved in 2013. It involves using a protein that induces an immune response in people and — wait for it — is combined with insect cells in order to replicate.
Even if this method might give you flashbacks to the movie The Fly, it has already resulted in a better mousetrap in preventing shingles. A new vaccine dubbed Shingrix is reported to prevent 90 percent of cases. People contract shingles when they get chicken pox. It then lies dormant before it appears decades later as painful blisters.
“The flu vaccine is very old tech, but people are very hesitant to move away from it because it is so tried and true even though it is not particularly effective,” Farzan said. “It is very safe.”
The yearly vaccine doesn’t trigger the necessary immune response in about 40 percent of the elderly, a population especially vulnerable to influenza, he said. The CDC says it’s impossible to determine how many people die of the flu but puts the number between 3,000 and 49,000 depending on the strain.
“Because flu viruses are constantly changing and the composition of the flu vaccine must be determined so far in advance, selecting the right influenza viruses for the flu vaccine to protect against is a challenging task,” said CDC spokeswoman Kristen Nordlund.
This year, she said, the flu virus reduces your chances of getting sick and having to go to the doctor by 42 percent.
“While these results underscore the importance of developing better, more effective flu vaccines, they also show that current flu vaccines do offer substantial public health benefit and that increased coverage could provide additional benefit,” Nordlund said.
The CDC, though, strongly encourages yearly vaccinations against influenza, saying that even if the formulation is not spot on it will help minimize symptoms of the virus, such as fever, chills, muscle aches, cough, congestion, runny nose, headaches, and fatigue.
Flu vacine effectiveness
- 2004-2005 — 10 percent
- 2005-2006 — 21 percent
- 2006-2007 — 52 percent
- 2007-2008 — 37 percent
- 2008-2009 — 41 percent
- 2009-2010 — 56 percent
- 2010-2011 — 60 percent
- 2011-2012 — 47 percent
- 2012-2013 — 49 percent
- 2013-2014 — 52 percent
- 2014-2015 — 19 percent
- 2015-2016 — 48 percent
- 2016-2017 — 42 percent
Source: Centers for Disease Control and Prevention