Universal Vaccines – Reality or Just Another a Pipedream ?
An interesting news item on 'universal' vaccines appeared
last week in the BBC News Health Section....
As someone with an active interest in vaccine development, the report certainly attracted my attention, and I think the methodology merits wider discussion as a possible 'game changer' in our approach to preventing human disease….
The concept of a ‘universal’ vaccine has been on the minds of those in the vaccine development field for many years, but the recent announcement is the first suggestion that such an intervention might actually be possible…and effective.
I should add straight away that the Stanford research project alluded to in the above linked article is
still very much in its early stages, and positive results have only been shown in lab
mice to date. The methodology is nowhere near entering human trials yet, and this will be the only way to
demonstrate whether a more universal approach to vaccination would be viable in the
human population. Acquiring and maintaining immunity is a lifelong process, and apart from anything else, the
difference in lifespan between humans and mice raises a major question about the
longevity of any ‘universal’ effects that might be seen in animal species, and also the implications they might have on our own long-term
acquired immunity. So no, the NHS won't be offering it any time soon....
How would ‘Universal vaccination’ actually work, and how does its mechanism differ from conventional vaccines ?
First, we need to look in more detail at how the ‘conventional’ vaccination approach works.
The well-established direct method relies on administering ‘foreign’ material, derived from the pathogen of interest, usually by intramuscular injection, to present a direct challenge to the recipient's immune system. The newer mRNA vaccines, which first hit the headlines in 2020 on the back of their rapid development for Covid, are a little different, and go about this in a slightly more roundabout way, by providing a genetic message to the muscle cell in the from of a specific engineered and packaged mRNA strand. This causes the muscle cell to produce the foreign antigen internally. The end effect is essentially the same, i.e the presentation of a foreign antigen to the immune system.
The presence of this foreign antigenic material somewhere it shouldn’t be (i.e. within your arm) then stimulates the immune system to mount a response. This includes production of both T-cells and ‘humoral’ (i.e. non-cellular) antibodies against the antigen by B-cells. Both of these products are highly specific for the antigen and can recognise it in preference to all the other components in the circulation. They will latch onto tightly to that particular antigen whenever they encounter it, and by doing so, effectively ‘flag’ it for destruction by a whole 'cohort' of other immune cells we all have at our disposal to do the heavy lifting work of dealing with the invader.
Thus immunisation ‘teaches’ the immune system to recognise (and hopefully destroy) a specific pathogen, and this immunity is retained over time. It is this 'immune memory' that helps us respond quickly to, and combat, any future infections by the same pathogen. This learned response is termed ‘acquired’ immunity and is key to our survival.
That's not the whole story of our immune defence mechanism, though – fortunately for us, we also have what is arguably an even more important 'first line' of defence in the form of what’s called ‘innate’ immunity. This is what kicks in as soon as we are infected by a pathogen which we haven’t met before, and to which we therefore don’t have any acquired immunity.
The innate pathway is essential for our short term survival in the face of a new and unknown infection, since it mounts a much more immediate response in the absence of prior experience of the pathogen. And it is the innate pathway that is utilised by universal vaccines.
The innate immune system is always available in the background, but normally exists on standby, remaining effectively ‘on watch’ i.e. on the lookout for anything it thinks is foreign and could present a threat. Specific 'self' recognition factors present in our own tissues and organs will normally ensure it doesn't attack them, and our innate immunity is only ‘mobilised’ into action when it detects an external threat. However, even the innate system does take some time to activate, and more importantly it may respond weakly, or even not at all in some circumstances (e.g. immunosuppression, immune-decline in old age, or immune ‘concealment’ via checkpoint mechanisms by the foreign agent, as in the case of cancer cells.)
Future universal vaccines would be designed to bypass this initial slow response activation step by providing an initial switch-on stimulus to the innate immune system, and then maintain it in an activated state. In doing so it could also bypass blockages to the innate system response of the sort we've just described.
The Stanford prototype vaccine adopts a 3-pronged approach to achieve this, with two existing drugs being utilised to stimulate one of the innate system's 'sentinel' cell types, the macrophages, while a third component stimulates a specific population of T-cells into action. This combined stimulus mobilises the innate system ready for prompt action, but does so in the absence of any specific threat.
(As an aside here, the term ‘vaccine’ is arguably a misnomer in that no specific antigen is present, and the stimulus is a non-specific one. I expect the terminology will probably stick anyway, though. I suspect Jenner will probably not be turning in his grave at the technical inaccuracy, given the tribute to his work already afforded by humanity's dependence on the conventional vaccination principle he discovered in the 19th century).
The key difference between the two approaches is thus in the breadth of the response, with the Universal vaccine effectively ‘pre-activating’ the innate system against all comers, allowing a faster and more effective response to any foreign 'invaders' rather than just one specific type.
The Stanford report published in the Science journal claims up to 1000-fold reduction in viral or bacterial uptake following an infection challenge with a wide variety of viruses, bacteria and even some common allergens.
"What’s not to like ?", you may ask. "How quickly can I get some of this wonder product, and get myself protected against, well, just about everything ?"....
Inevitably with an early discovery such as this, there are important questions to ask…and answer before the vaccine development industry rushes into developing and marketing it.....
The Down-side
Firstly, there are some concerns about the effects of over-stimulating a system that’s designed to work only when it’s actually needed. An ‘always on’ status in any system will usually generate stress (as many of us are finding out at work or on social media), and in the case of immunity, could make it less able to respond effectively in a crisis when we really need it to be fully 'on form'.
The other major question is whether continual activation of an otherwise 'on-standby' immune system would increase the likelihood of auto-immunity. This is the term used to describe one of the many conditions where our own immune systems respond to ‘self’ i.e. start to attack our own tissues and organs, sometimes with devastating results. Experiments in a small short-lived rodent species such as the mouse (or indeed even in larger animals) could not possibly answer this question, and a definitive answer can only come from human clinical studies, where much more time would need to be allowed for the problem to manifest itself.
There's also the more technical issue of how to access to the target tissues and organs effectively. Intranasal administration, although seemingly effective in the mouse, might not be adequate to reach the lungs in humans due to the length and extent of our bronchial tree. Thus nebuliser dosing might be required to achieve adequate penetration, and we would need to be sure that absorption was efficient enough to activate effectively, without causing damage to the mucosa and alveoli in the process.
Last, but not least, is the question of how long-lasting the
effects of each administered universal vaccine dose would be. The mouse experiments with an intra-nasally
dosed prototype seemed to indicate an effect persistent out to ca 3 months. This could be
useful if reflected in human subjects, but would require more frequent boosting than is normal for conventional vaccines. Much shorter durations of effect could well make their use impracticable.
I should emphasise here that, by stressing potential snags with the approach, I'm not in any way belittling the achievement. It could be a real game-changer if we can identify, and then circumvent, any potential 'show stoppers' of the sort I've mentioned.
Interestingly, the concept of activating the innate immune system to protect ourselves against disease isn't a new one - we have been using the Bacillus Calmette-Guérin (BCG) vaccine for over a century now, most notably against that perennial menace to our species, the tuberculosis mycobacterium (TB). Many of the older generation may well have received it at school - see footnote below for an interesting story on the early development of vaccines for TB. Although death rates ave halved since 2000, the disease is still one of the most prevalent infectious diseases, with ca 1.5M deaths worldwide in 2025 (see Figure 1).
How would a universal vaccine work in practice ?
We would probably not expect such a wide-ranging tool to work in isolation, but rather as a supplementary defence in conjunction with conventional vaccination.
Thus, the primary goal of a universal vaccine would initially be as a 'holding-operation', acting as a deterrent and allowing the immune system to fight off a wide range of seasonal infections during the ‘respiratory season’ more effectively.
In the early
stages of a pandemic, it could also be very valuable if used to reduce the initial viral burden in a vulnerable population, pending the development of a specific conventional
vaccine against the new pathogen. It could thus potentially save lives and reducing the need for self-isolation and lockdowns (it took ca 9 months to engineer and test the first Covid vaccine, during which time hundreds of thousands died and we suffered multiple lockdowns). As such, it is of significant interest to vaccine developers in potentially tackling the next pandemic agent, which is widely expected to be a new and much more deadly flu virus variant.
If such a universal therapeutic approach were proven to be both safe and effective, its key advantage would be its very non-specificity. We are all plagued by legions of different respiratory viruses on an annual basis, the vast majority of which are currently ‘un-vaccinatable’ i.e. too nimble and ‘fleet of foot’ in evolutionary and mutational terms. This deters vaccine developers from even contemplating going to the lengths of developing a specific antigen vaccine against any one of them, let alone sequencing its genome; we would need to do this to produce an mRNA vaccine. An effective universal vaccine might actually protect us from the worst effects of some of these perennial, and frequently quite debilitating, pests.
Who knows…that universal panacea and 'holy grail' of the pharmaceutical world, a cure for the common cold, may actually be nigh !....
First published: 22.2.26; updated 4.3.26
Footnote 1: After reading this article, readers may have already asked themselves the question - why aren't there more effective conventional vaccines for TB, given that a) it is still one of the world's greatest killer diseases b) It is rapidly evolving antibiotic-resistant strains and c) Having been virtually eradicated from 1st world countries like the UK in the past, it is rapidly gaining ground again here (largely as a result of immigration from the 3rd world, where it has remained endemic throughout).
The answer is that Mycobacterium tuberculosis is a both a slippery customer, and wily adversary, as are the mycobacteria as a class. It has evolved clever ways of 'fooling' our immune systems. Amongst other things, its small size and morphology makes it able to actually survive inside human macrophages, and it can also effectively hide elsewhere within the body in a latent state, making it hard for the immune system to fully eradicate.
The bacterium can also actively manipulate the host immune system to prevent
its destruction, by preventing phagolysosomal fusion, and thus blocking the
macrophage from killing it. all of these age-old strategies it has evolved to frustrate our defences make it very difficult to vaccinate aainst in the conventional way. We are fortunate to have BCG, which has been around for more than 100 years, and does protect children against infection. However, BCG is relatively ineffective against infection and spread of the disease in adults, who are the main transmission vectors. Efforts are still being made to develop new vaccines against TB, with subunit antigen vaccines looking the most promising candidates so far. The vast majority of deaths remain in 3rd world countries in Africa and Asia, but this could change if antibiotic resistance rears its ugly head anew.
We can only hope that one or more of these strategies bears fruit before we lose our first line antibiotics to TB resistant strains, and we revert to 'Victorian style' death rates from the disease...
Figure 1: WHO stats for worldwide deaths from TB 2000-2025
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