What is the prevailing thought re. this vaccination under these circumstances?
The problem is, 'prevailing thought' on 'social media' is about as varied as 'varied' can be! Compounding that problem are two issues: one, that vaccination is itself a very complicated issue in many respects, and these complications result in false understandings of almost every aspect...then, people who misunderstand spread those misunderstandings.......and on and on; two, even 'prevailing thought' among those who know the science/fact varies widely....because those opinions will have been formed by one of (at least) two 'sides' within the veterinary 'industry'......and, industry, by nature, is profit seeking.
Dr. Lisa Pierson is a respected Veterinarian who has written an article on vaccination....a read of her background shows that she's 'worked in the trenches' (so she's not speaking from La La Land) and she's seen the effects of dangerous vaccination and over vaccination).
I really, really recommend that you read the full article - I'll quote the piece specific to your question simply because there's no direct link, but, the full piece is, imo, a must-read/understand. Here it is from the top: Vaccines for Cats: We Need to Stop Overvaccinating by Lisa A. Pierson, DVM :: Vaccines are very important but do carry risks
Feline Leukemia (FeLV):
Feline leukemia (the disease that results from the feline leukemia virus versus a primary cancer), is a complicated disease. It typically attacks the bone marrow of the cat but cats vary in their response to the virus. Some cats clear the virus from their system and become FeLV 'negative,' some cats live for many years with the virus in their body but are not symptomatic, and some cats become ill and die within a few years of becoming infected.
FeLV is NOT highly contagious and its transmission requires prolonged intimate (i.e., sharing food/water, mutual grooming) contact with an infected cat. Natural immunity is very strong in most cats by the age of 1 year. AAFP guidelines suggest vaccinating all kittens but the vaccine is recommended in adults only if they will be in contact with a known FeLV positive cat - which would be a very rare situation.
I disagree with the recommendation to vaccinate all kittens. None of my own cats have ever been vaccinated for FeLV - not even as kittens - since they reside indoors and will not be in contact with a FeLV positive cat.
Do not vaccinate kittens for FeLV unless your kitten is going to be outside (rarely a safe place to be for any kitten or cat) or is going to be housed with an FeLV positive kitten or cat.
Do not vaccinate adult cats for FeLV - even if they have access to the outdoors - since natural immunity to this disease is very strong by the time the cat is ~1 year of age. If an adult cat is going to be living with a FeLV positive cat, then vaccination should be considered.
If you are more comfortable vaccinating a cat that goes outside, please do not vaccinate him yearly. Vaccinating one time with a PureVax (the only NON-adjuvanted option) vaccine would fit within my comfort zone.
*emphases are Dr. Pierson's
In there, you see a reference to "PureVAX"....if you haven't yet read the rest of the article, she's speaking of a non-adjuvanted vaccine - using that kind minimizes adverse reactions - these are generally more expensive. There is a veterinary limited-service low-price chain that uses ONLY PureVAX for rabies (and, so I suspect FeLV as well because the pricing is identical): https://www.vippetcare.com/
(at least, $31 a pop sounds 'low-price' to me)
If you decide to vaccinate, there's a new technique to further reduce the dangers associated with vaccination site sarcomas: vaccinate in the tail ! Research has proven its effectiveness...there's even a video: Google "tail vaccination in cats"
Hope something there helps!