Nasal vaccines: are they better than the IM versions?
Myron Yaster MD and Kim Strupp MD
When the Covid vaccines first came out, I volunteered at a local hospital and several churches as a vaccinator. Initially the people I vaccinated were mostly the elderly and people with underlying conditions putting them at most risk. And also remember, this is when thousands were dying of the disease every week. The joy of When I was finished giving the shot, the response from most: “you mean you’re done? I didn’t feel anything!” I would then reply “I’m a pediatric anesthesiologist and I do this for a living when I’m not volunteering!” One memory that I can’t forget though involved a 25 year old who was so terrified of needles that he had to be held on the floor and restrained in his fiancée’s lap for his shot. I was both mortified and amazed and wanted to tell the guy to “just get a life!” It turns out though that there are many people who are needle phobic--about 20-30% of adults have some fear of needles! But more importantly, as you will soon discover in today’s PAAD, vaccines delivered by nasal spray may actually be more effective than those administered by the IM route. In today’s PAAD, we will review an article by S Sutherland1 in the November issue of Scientific American detailing the science behind nasal vaccines.
And again just as a reminder: You too can be on the frontline of influenza vaccination.2,3 The perioperative period is an almost ideal time to recruit pediatric patients to get their yearly influenza vaccines. By administering the vaccines while children are anesthetized for procedures, one of the barriers against vaccination, pain, is removed. I’ve asked Dr. Kim Strupp who has championed this idea and is a member of the PAAD’s QI/implementation science group to help with today’s PAAD. She is an ideal person to consult (kim.strupp@childrenscolorado.org) if you are interested in implementing this flu vaccine program into your practice. Myron Yaster MD
Original article
Sutherland S. No More Needles: Gentle nasal sprays are being tested as vaccines against COVID, the flu, RSV, and more. They may work better than shots in the arm. Sci Am. 2024 Nov 1;331(4):34. doi: 10.1038/scientificamerican112024-5PSm5KM483z5dKb4VHwmne. PMID: 39405232.
Vaccines are without question, the most important public health measures, really miracles, of modern medicine. They provide protection against viruses and bacterial pathogens by producing immunity. It turns out that nasal sprays produce a better response because nasal sprays are aimed directly at the mucosa where many viruses first enter the body: Mucosa from the nose, mouth, respiratory tract down to the lungs is where our bodies encounter the vast majority of pathogenic threats, is our first line of defense, and produces different types of immune protection. A detailed description of the advantages of nasal vaccination and how they work is best understood by the Figure below.
Mucosal immunity not only includes adaptive immunity with production antibodies and primed immune cells, it also activates the innate immune system including macrophages and tissue-resident immunity with memory T cells and IgA antibody production. This immunity may prevent the virus from ever infecting the host and it may prevent it from invading deeper tissues. Additionally, attacking the virus in the nose could prevent the disease from being transmitted to others due to lower overall viral load.
Needle free delivery offers some other advantages including equity in resource limited countries. “Some of the nasal sprays in development don’t need deep-cold storage, so they might be easier to store and transport. And a nasal spray or an inhaled puff would be much easier to administer than a shot. No health professional is required, so people could spray it into their noses or mouths at home.”1
There are many hurdles still ahead but nasal spray vaccines are the way of the future and will be how many future vaccines will be given in the future. Send your thoughts and comments to Myron who will post in a Friday reader response.
References
1. Sutherland S. No More Needles: Gentle nasal sprays are being tested as vaccines against COVID, the flu, RSV, and more. They may work better than shots in the arm. Sci Am 2024;331(4):34. (In eng). DOI: 10.1038/scientificamerican112024-5PSm5KM483z5dKb4VHwmne.
2. Rao S, Morrissey T, Ziniel SI, Mandler T, Yaster M, Strupp KM. Influenza Vaccination in Perioperative Settings: A Teachable Moment. Anesthesiology 2022;137(6):745-747. (In eng). DOI: 10.1097/aln.0000000000004341.
3. Meyer AJ, Smith JR, Wright TL, Engler LJ, Bigham MT, Bhalla T. Pediatric influenza vaccination in the perioperative setting: A quality improvement project. Pediatric Anesthesia 2024;34(2):167-174. DOI: https://doi.org/10.1111/pan.14790.