Which “Flu” Should We Worry About in 2018?

The 2018 winter flu season "unquestionably falls into a bad year," says Anthony Fauci, MD, director of the National Institutes of Health National Institute of Allergy and Infectious Disease.

A recently published Centers for Disease Control and Prevention (CDC) report confirmed what hospitals around the U.S.A. already know, that 2018 is a bad year for the flu.

During a recent January 12 call, the CDC noted that the flu was widespread across the continental U.S.A. and in the UK, following the extensive Australia flu season.

In theory, we should be better prepared today than a hundred years ago when the 1918 Spanish flu pandemic altered the course of history.

One-fifth of the entire human population was infected. In less than one year, the Spanish flu claimed the lives of about 50 million people, four times more than those lost during World War 1.  

Modern surveillance systems enable health providers to detect pandemics far quicker than before, with seasonal flu vaccines able to protect people against whatever strain of the virus is causing the pandemic.

Flu viruses circulate all year round, all over the world and they are constantly evolving through mutation. This means even viruses of the same subtype can be slightly different, and so vaccines against the subtype won’t necessarily work on newly mutated forms.

Flu viruses are also shared around the globe thanks to modern air travel.

But, what should the USA be prepared for during 2018?

In the USA, there are four types of influenza viruses: A, B, C and D:

• Human influenza A and B viruses cause seasonal epidemics of disease almost every winter in the USA..
• The emergence of a new and very different influenza A virus to infect people can cause an influenza pandemic.
• Influenza type C infections generally cause a mild respiratory illness and are not thought to cause epidemics.
• Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people.

Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: the hemagglutinin (H) and the neuraminidase (N). There are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes. (H1 through H18 and N1 through N11 respectively.)

Influenza A viruses can be further broken down into different strains.

Current subtypes of influenza A viruses found in people are influenza A (H1N1) and influenza A (H3N2) viruses. In the spring of 2009, a new influenza A (H1N1) virus emerged to cause illness in people.

This virus was very different from the human influenza A (H1N1) viruses circulating at that time. The new virus caused the first influenza pandemic in more than 40 years.

That virus often called “2009 H1N1” has now replaced the H1N1 virus that was previously circulating in humans.

Influenza B viruses are not divided into subtypes but can be further broken down into lineages and strains. Currently circulating influenza B viruses belong to one of two lineages: B/Yamagata and B/Victoria.

Influenza A (H1N1), A (H3N2), and one or two influenza B viruses depending on the vaccine are included in each year’s influenza vaccine.

Getting a flu vaccine can protect against flu viruses that are the same or related to the viruses in the vaccine. Information about this season’s vaccine can be found at Preventing Seasonal Flu with Vaccination.

The seasonal flu vaccine does not protect against influenza C viruses. Additionally, there are many other non-flu viruses that can result in influenza-like illness (ILI) that spread during flu season.

Most pharmacies in the USA offer FDA approved flu vaccines.

The flu shot cost varies depending on your insurance and which state you live. The CDC Vaccine Price List provides the private sector vaccine prices for general information.

Flu vaccine discounts can be found here.

Vaccines, like any medicine, can have side effects, says the CDC. You are encouraged to report negative side effects of vaccines to the FDA or CDC.