FA16 Immunization Module’s Updates
Nasal Spray Flu Vaccinations, why aren't they more common?
Listening to Dr. Tapping's lecture on vaccines, I heard him mention a nasal spray vaccine. Why aren't those more common?! I imagine most people would choose the nasal spray over getting a shot.
Looking at the CDC's website, they are recommending that people not get the nasal spray vaccine (called LAIV4--Live, Attenuated Intranasal Vaccine Quadrivalent) "In light of concerns regarding low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013–14 and 2015–16 seasons." (Grohskopf et al., 2016). If anyone wants to comb through the most recently presented data (from 2015-2016), the CDC has the slides from it's meeting here:
http://www.cdc.gov/vaccines/acip/meetings/slides-2016-06.html
I spent about 20 minutes looking through it and found a few graphs on the overall effectiveness of the LAIV4 vaccine this year (from http://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2016-06/influenza-06-ambrose.pdf). I've put one of them below.
I'm not sure if ~50% is a good overall effectiveness for a vaccine, but it seems reasonable? Another slide from the same presentation compares LAIV4 to a different flu vaccine, called IIV (Inactivated Influenza Vaccine). This graph shows that LAIV4 does have lower overall effectiveness than the IIV vaccine.
If anyone else knows more about this or wants to take this investigation further, that would be great. Don't despair about having to get a flu-shot for the rest of your life, the CDC's recommendation is just for 2016-2017, so there's always next year!
Grohskopf LA, Sokolow LZ, Broder KR, et al. Prevention and Control of Seasonal Influenza with Vaccines. MMWR Recomm Rep 2016;65(No. RR-5):1–54. DOI: http://dx.doi.org/10.15585/mmwr.rr6505a1.
This is a very interesting subject! I have never heard anything about nasal vaccines. As mentioned above by Zheng, that would make sense that the increased temperature would decrease the efficacy of the vaccinations. Maybe nasal vaccinations are the way of the future. They would definitely be more pleasant for children.
https://www.ncbi.nlm.nih.gov/pubmed/27613072
This suggests that some of the decreased efficacy during the 2013-14 year may have been due to exposure to increased temperatures and increased sensitivity of that year's vaccine to heat.
In addition, this paper (https://www.ncbi.nlm.nih.gov/pubmed/27613072) suggests that vaccines delivered through the gut mucosal membranes are effective at generating an immune response, such as against polio. I wonder if there's a large difference between nasal and gut immune response and recognition, and if those years of ineffective vaccines were due to environmental factors.
@Zachariah Adham. There is some history with the nasal vaccine especially as far as efficacy is concerned. This should start a good discussion!
EDIT: I've realized that the CDC is recommending people don't get the spray because of low efficacy against Influenza A, and the graphs I've shown are overall effectiveness (likely combining efficacy against multiple subtypes).