The Centers for Disease Control and Prevention (CDC) issued a press release a couple of weeks ago about some of the preliminary data of the 2014-2015 flu season. There is a chance that this flu season could be severe, particularly for the elderly, children under five, pregnant women, or those with medical conditions that put them at increased risk for experiencing complications. There’s also a chance that this year’s vaccine is less effective than some other years but that doesn’t mean there’s not benefit in getting vaccinated.
This season is facing challenges due to the fact that strains of influenza A H3N2 appear to be most common. These strains have the potential to cause severe illness, and were also the most common during the three most deadly years of the last decade. Compounding the problem, these strains are also more likely to “drift”, mutate and evolve slightly different properties than what are targeted by the seasonal flu vaccine. This appears to be the case for some of the earliest confirmed flu cases of the season, prompting the CDC to say that for those that come in contact with a drifted strain, the vaccine’s efficacy may be reduced. This does happen sometimes, but those who received the flu shot are still offered protection against the drifted strain.
Viruses and bacteria mutate over time that’s why we have drug resistant organisms and why drug companies create a different flu vaccine every year. The actual vaccine created is based on calculated risk by determining which strain of the flu virus is most likely to be predominant. There’s no way to anticipate how the virus may mutate and create a vaccine based on what may, or may not, happen.
The flu vaccine is developed months ahead of the flu season, in order to have time to manufacture enough units for as many people as possible. This requires that scientists predict which three or four strains will be most common. The World Health Organization made its recommendations for the strains to target with the vaccine in the middle of February. The drifted H3N2 virus was discovered at the end of March, but at the time, it was in such small numbers that it wasn’t believed to be of much concern.
Even if H3N2 has drifted and the vaccine does not provide maximum protection against that particular strain, it can still lessen the severity of the illness. Additionally, the vaccine also protects against other strains that a person may encounter, so health officials are still recommending the flu shot to anyone who has not yet received it.
Sometimes facts aren’t as fun as fiction and often with the media sensationalizing a story tends to attract viewers and readers and sell advertisements. There have been claims that the CDC has issued an “apology” about this year’s flu vaccine. Nothing could be farther from the truth. The CDC readily acknowledges that the H3N2 virus has drifted and the vaccine is less effective but the benefit of becoming vaccinated outweighs the risk of not doing so.
The 2014 – 2015 flu season vaccine may not hit the kill zone but it can lessen symptoms and slow the spread. Vaccine creation for a virus capable of mutation is never going to be an exact science and like many decisions in life you have to take into account the information at hand and make the best decision for that moment in time. The vaccine may not prevent the flu but it can lessen symptoms and that’s incredibly important to three types of people who are more likely to die or be hospitalized for the flu – pregnant women, the elderly and young children.
As for the healthy, being less sick is better than being more sick so the rumors about there being no benefit from the flu vaccine are easily disputed by FACT…