January is peak flu season, so if you haven't caught the flu yet - congratulations! Of course, flu season doesn't really end until April. Consider asking your physician if is it still worthwhile to get a flu vaccine if you haven't already. Last year's flu season was hard on many families. Too many children and babies contracted the flu and didn't survive. Child mortality from the flu was up last year, higher than it had been in 9 years prior, while the effectiveness of the flu vaccine was somewhat low. Worsening the situation was a record low percentage of vaccinated children and adults in the 2017-2018 flu season. I’m certainly not sciencey enough to say whether that was correlation or causation, but I do know this: even a mildly effective vaccine helps reduce the duration and severity of the flu if you catch it. While last year’s vaccine wasn’t very effective at preventing the spread of the disease, this year’s vaccine is kicking influenza butt!
What Is Vaccine Effectiveness?
The flu is spread by a virus which is a living single-celled organism. Viruses and bacteria can evolve over time as they learn the different ways we try to defeat them. This evolution is why we have MRSA - an antibiotic-resistant bacterial infection. Basically that bacteria changed just enough over time that it outsmarted our attempts to control it with antibiotics. Every year, the flu virus does the same. We generally call the different strains Influenza A and Influenza B, but the strains don’t look the same year to year.
The Flu Virus Mutates Every Year
Since our viruses are learning how to find loopholes to get past our protections against them, scientists have to recalibrate the flu vaccine every year. Of course, there's no way for scientists to be certain which mutation will be the most common during a particular flu season. That means the flu vaccine is an educated “best guess” as to which strands will be the most virulent. Some scientists call this a vaccine-virus match. While last year’s vaccine-virus match only addressed about 40% of influenza viruses making the rounds, this year’s flu vaccine is extremely well-matched. Early estimates place this year’s vaccine efficacy rate between 50 to 80 percent, although many caution that it is likely still too early to tell.
What’s Different About The 2018-2019 Vaccine?
In response to last year’s vaccine-virus mismatch, epidemiologists redesigned the current vaccine. Quadrivalent flu vaccines in the 2018-2019 flu season include protection against the following strains: A/Michigan/45/2015 (H1N1)pdm09-like virus, A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus (updated), B/Colorado/06/2017-like (Victoria lineage) virus (updated), and B/Phuket/3073/2013-like virus (B/Yamagata lineage). Epidemiologists are reporting an early uptick in the B/Yamagata strain, which normally hits later in the flu season. Unfortunately, some flu vaccines contain just the first three strains - only quadrivalent vaccines contain all four. If a needle isn't your style, you can opt for the nasal spray flu vaccine instead.
The Flu Shot Is The Best Protection Against The Flu
Last year’s flu season claimed the lives of over 180 children - 80% of whom were not vaccinated. Since the flu vaccine takes two weeks to provide immunity, it’s possible that the 20% who did receive the vaccine contracted the virus in those two weeks. Alternately, they may have contracted a strain that wasn’t covered by the vaccine match. It’s important to vaccinate yourself and your children to give your family the best chance at staying healthy. Dr. Lehman, Professor of Clinical Pediatrics at UCLA, noted that getting the flu vaccine is important to developing “herd immunity”, which protects those most vulnerable to the illness and those who are unable to be vaccinated for health reasons. Even if the vaccine is only 20-30% effective, the herd immunity factor begins to kick in.
With any luck, we will avoid the severity of last year’s flu season which reached epidemic levels for nearly three months. We’re at the height of flu activity this month, and scientists predict it will drop off over the next few weeks. Whether you got the vaccine or not, I wish you the best of luck in avoiding the virus and staying healthy this flu season!
As always, consult your doctor to determine the healthiest choices for your family.