2017-18 CDC flu vaccine recommendations

​The CDC just came out with their 2017-18 vaccine recommendations (see https://www.cdc.gov/mmwr/volumes/66/rr/rr6602a1.htm​ ):

--vaccine should be given to all >6 months old, unless contraindicated (then consider chemoprophylaxis with influenza antivirals)

--vaccine viruses included in the 2017–18 U.S:

    ​-- Trivalent influenza vaccines: A/Michigan/45/2015 (H1N1)pdm09–like virus, A/Hong Kong/4801/2014 (H3N2)-like virus, and B/Brisbane/60/2008–like virus (Victoria lineage). This is a change in the vaccine composition from last year in the A(H1N1)pdm09 component

    --Quadrivalent influenza vaccines will contain these three components and also cover the additional influenza B vaccine virus, a B/Phuket/3073/2013–like virus (Yamagata lineage).

--vaccines recommended include: Afluria Quadrivalent (IIV4, if ≥18 years, but Afluria Trivalent IIV3 can be used for those ≥5 years); Flublok Quadrivalent (RIV4); and FluLaval Quadrivalent (IIV4, previously licensed for ≥3 years, but now expanded indication to include those ≥6 months) [IIV=inactivated influenza vaccine; RIV=recombinant hemagglutinin influenza vaccine]. 

--Pregnant women may receive any licensed, recommended, age-appropriate influenza vaccine.

--High-dose vaccine (Fluzone High-Dose or Fluad, inactivated tri-valent vaccines) can be given if ≥65yo, though it is okay to give the standard dose vaccine. There have been a couple of studies finding that the high-dose vaccine is more effective in those ≥65yo, but “no claim of superiority was approved for the package insert”. The bottom-line is that it is more important to get the vaccine than to delay the vaccine in anticipation of getting this probably more effective high-dose one.

--can give IIV or RIV to those taking influenza antivirals

--FluMist Quadrivalent (LAIV4) should not be used during the 2017–18 season due to concerns about its effectiveness against influenza A(H1N1)pdm09 viruses in the United States during the 2013–14 and 2015–16 influenza seasons.

--see article for a full list of the vaccines available, but note that this list does include the LAIV, which is not recommended but included anyway, along with the recommendations not to use it. But with information on how to use it if one wants to [which I think reflects our lack of a dominant and cohesive public health approach, allowing profit-oriented drug companies to peddle ineffective drugs….. ]

--they do comment about the timing of the vaccine, noting that the vaccine should be given by late October (though in kids <8yo who need 2 shots, the first one should be as soon as possible). They acknowledge the studies finding potential waning immunity if the vaccine is given too early (see recent blog ), and comment that decreasing vaccine effectiveness is especially pronounced in the elderly [though I believe all of these studies were before the high-dose vaccine for the elderly]​. The point is that any inactivated vaccine is still better than no vaccine, so one should carefully avoid putting off giving the vaccine if that might result in nonvaccination [which I whole-heartedly agree with]. They also mention potential programmatic constraints (if one waits til end of October, can the institution/staff gear up for this large bolus of people coming for vaccines?) They recommend against booster vaccines later in the season for those who get the vaccine early. The end of October was chosen because of potential for earlier flu outbreaks, though 74% of flu season from 1982-2016 had peak flu activity beginning in January (it takes 2 weeks post-vaccination to get immunity). 

--also, for travelers, the timing of vaccine might be different: flu season in the Northern Hemisphere is October through May, Southern Hemisphere April through September. And any time in the tropics.

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so, the CDC does acknowledge the potential issue of waning immunity if the vaccine is given too early, but does emphasize that delaying the vaccine could result in fewer getting it. i still feel that waiting is appropriate for many patients, and will reprint my comments from the last blog on waning immunity:​

So, what makes sense (at least to me)?

--it certainly makes sense to give the vaccine early:

    --in those who are young and need 2 shots (which is why the above study excluded those younger than 9 years old)

    --and, especially in those who might not come back later for a shot just before the flu season begins

--but based on these studies, I will be holding off on giving the vaccine to:

    --my patients who come to see me regularly in the office for management of their chronic medical/psychosocial conditions

    ​--those in home care who can get the shot at home at any time

--and, we do get some significant warning, eg from the CDC weekly tracking system, typically with at least the 2 weeks’ notice that it takes for the vaccine to work​