As we race towards Christmas and into the New Year and with springtime firmly in the rear view mirror, many of us potentially with itchy eyes, find ourselves still reaching for the tissue. You might be responding to all the pollen in the air and so for this week at Christmas last show for 2020, I wanted to talk about the topic of allergens because it's not just pollen allergens, that people will respond to. Any of you who've been following the news about the introduction of Pfizer's new COVID-19 vaccine, have possibly been alerted to some of the alarming news reports saying that many people have been getting an allergic reaction to the vaccine. I want to talk about the scientific underpinnings of this. What is an allergen? How do you come into contact with allergens? How does this affect how we think about vaccines and what you should know over the holiday season?
Firstly, I want to define what an allergen is. Essentially this is any substance, usually a protein which can elicit an immediate clinical response, like the itchy eyes, the constricted throat, and in very serious cases an anaphylactic reaction. Most of the allergens are proteins. We've talked a lot about IgE reactions over the last couple of months on this show. And the three ways that individuals become exposed to allergens are ingestion, eating them or inhaling them. One of the central topics of this show is the inhalation response to allergens like mould, mould spores, mould fragments, nano-sized, and micron size aerosolized cell wall fragments from mould and bacteria. I go on and on about this. These are just two of the typical types of classes of allergens, but there are a lot more. And the third way that individuals become exposed to unwanted allergens is through injection.
So today we're going to go through the top 10 reasons, your relationship with hypersensitivity is toxic. To kick this off, I need to say that it is this hypersensitivity reaction, which causes all the problems. The first problem issue, which elicits an immune response is pollens. There are three main classes to this, grasses, weeds and trees. Grass pollen obviously is the most common, which leads to allergic rhinitis and asthma. And this is a worldwide problem, but other types of pollen, ragweed pollen from all the weeds that we see often by the sides of the roads are in our gardens. They also contribute to allergic rhinitis as well and pollen induced asthma. But then think about all the trees. These produce copious amounts of pollens, and they are very obvious. I see these all the time when we do spore traps. In fact, I got an email from a client just this morning asking me whether or not a lot of the higher fungal loads present in the outdoor reference control, when we do spore trap testing inside people's home, could be also contributed by all the pollens.
Really the answer's yes, because pollens are perfect vehicles for a lot of moulds. If we go into the second most common class of allergens, they are definitely the fungi. I talk about this every single week on this show, they definitely contribute significantly to allergic disease throughout the world. And the most common allergens include Alternaria, Aspergillus, Cladosporium, Aspergillus fumigatus. Now, high spore loads inside peoples' homes can lead to unwanted hypersensitivity reactions and the best way to mould proof your home is to jump on any water damaged building areas, stop water leaks, perform something called source removal, which is remove the mould affected water damaged building materials, totally. But even also use your air conditioner, especially in summer and in many cases that will reduce indoor humidity. That is really important.
The next main source of allergens falls under the umbrella of climate change. Certainly, a couple of weeks ago, I talked about changing fluctuating temperatures. These strange weather patterns that many of us are noting and how this affects coffee growers and the location of ideal farming land for coffee and the predicted impact of rising temperatures. If we look at the environmental changes, then we need to recognize that these one or two-degree shifts that are predicted to be experienced this century, will affect vegetation and will likely lead to higher allergic disease burden. Mainly due to the fact that there will be an early onset to the pollen season.
So there you have it. Here are the first three of the top 10 reasons why allergens could affect you in your home. If we move on to the fourth method or problem, we have to talk about dust mites. Certainly, when we go into people's homes, we're always on the lookout for the amount of dust. We often use type lifts to sample dust off and on top of bookshelves or in hard to reach and clean places because using type lifts, you can capture the dust. In that dust, you can often measure the quantum of mould spores, pollens, and a whole lot of other insect debris. That gives us a very good understanding of what's going on, but it leads me on to the other thing about dust, that this is an ideal home for, you guessed it, dust mites. These are the fourth most common allergen trigger.
The reason for this is that they feed on human skin and they're very small, they have eight legs and they love warm human conditions. Therefore, their numbers tend to peak in the summer period. Now, what about other sources of aeroallergens? Obviously, I've covered some of the micro biological issues like those aeroallergens from bacteria, yeast and fungi that become airborne or could grow on water damaged building elements. What about other common triggers such as animal aeroallergens? Now we can't go past the fact that many people are in fact allergic to dogs and cats. And again, why is this occurring? It's not necessarily the hair. In many cases, it's the skin which is referred to as dander, which people respond to as well as the saliva and urine. Many of you may not realize that research has been done following people's exposure to cat and dog allergens, and a cat can release allergens into the air that remained buoyant for weeks to months.
In many cases, up to nine months after the animal has been removed from the house and these cat allergens can easily adhere to clothing and then can be found distributed in public places. You don't have to see a cat to respond to the cat allergen. And again, other research has shown that sensitized or hypersensitive children are often responding to cat allergens in other children's clothing that they are being exposed to in the school yard. The sixth allergen is cockroaches. Now cockroaches are particularly common. They're not necessarily always found inside people's homes, but they are very, very common. It is the cockroach protein very much like the dust mite allergen that easily becomes airborne when disturbed. We definitely want to limit the cockroaches that are present in our homes. I certainly know in Sydney, we see them quite commonly, less so in Melbourne, but certainly cockroaches seem to be a feature of certain urban environments.
I'm moving right along through the top 10. I want to talk to you about how some allergens lead to extremely serious hypersensitive reactions, such as anaphylaxis. You only have a few minutes to deal with an anaphylactic person. I'm going to talk about people who have adverse reactions to bee, wasp or Hornet stings. And no, this isn't just in like the opening scene to Blue Velvet, the movie, the art-house movie, which opens with a lady being stung and falling down on screen. But why I always remember that opening scene is that one of my friend's mothers who lived up the road after we left school, she was stung in her front garden and unfortunately passed away. I've never forgotten the fact that this bee sting or our seventh allergen is a particularly serious trigger for many people. How does this happen?
Well, it's not an aeroallergen, like the mould spores. It is a venom problem. Essentially the bee, wasp or hornet, injects its venom into the person. If people are sensitive to that, they will get an adverse health reaction. Now there are other living creatures that cause allergic reaction, ants and spiders. I'm going to save those for another day, but I want to get on to now the eighth, most common allergen trigger. This is drugs and no, it's not the illicit type of drug reaction that I'm referring to. I'm talking about injectable pharmaceuticals. And that leads me on to Pfizer's COVID-19. I have to draw your attention to this publication, which came out in Science just a couple of days ago. In it, they are reviewing the fact that the messenger RNA, which is used in the Pfizer vaccine also has something called polyethylene glycol. People appear, in very low numbers to be reacting to this PEG present in the vaccine.
This obviously we don't want. This is a very clear IgE reaction. If we look at these types of drug reactions, in many cases, they are over-reported by people. And certainly, we need to be very aware of this when we are reviewing a lot of the news stories that are coming out about adverse drug reactions, but also mindful that this is well-known and that many drugs are in fact too small to incite an allergic sensitization, but it's definitely known to occur. Certainly in the case of the COVID-19 Pfizer and Moderna's clinical trials of this, even though tens of thousands of people have been participating in the trials, both of the studies by those main pharmaceutical companies deliberately excluded people who had any history of allergy to injectables. Now that doesn't mean that if you are allergic to, for example, pollen or mould or dust mites, that those people didn't participate in the trials, it just means that they reduced the susceptible people who could potentially have an adverse drug reaction.
When I talk about this polyethylene glycol issue, the research in science showed that 72% of people had a raised antibody level to PEG in their system. This is not an uncommon reaction. In fact it's been well-known since 1999, when research by the Walter Reed Army Institute, also described a new type of drug induced reaction. We do need to be aware of this and also well aware about the fact that these vaccines will be given under medical supervision and therefore people can be closely monitored for any adverse anaphylactic type reaction, but be well aware that the Center for Disease Control has recently issued an interim clinical consideration warning for the use of messenger RNA, COVID-19 vaccines because of these newly reported allergen induced allergic reactions, which could be potentially fatal.
Again, remember allergens cause problems due to inhalation, ingestion, or injection. That leads me on to the ninth way that people can have a problem to allergies. And that is those individuals who respond to, for example, latex. Latex is natural rubber produced by the rubber tree and in spina bifida patients, 75% of them have an adverse allergic reaction to latex. The statistics are quite alarming in the general population, where six and a half percent of people show an adverse allergic reaction, a skin irritation response to latex gloves. This can also be more serious, lead to allergic rhinitis, asthma or even anaphylaxis. This is particularly serious for anyone who has routine health care with healthcare personnel wearing latex gloves.
Now we're nearly at the conclusion of the top 10 list and the final, final allergen is food allergies. Food allergies are extremely common and there are essentially two classes of food allergy. Class number one is the most well-known and leads to gastrointestinal upset, but class two food allergies lead to allergic sensitization. This could be an inhalant allergy response. In that graphic that I just put up, you saw the classic peanut allergy response. Any of you with children would know that it's been drummed into us as parents not to send, nut containing products with your child to school.
In any case, as we move towards 2021, we need to be very mindful of all of the different environmental factors that could impact on public health. Certainly, anyone who has been following my show for the last year and a half would know that weekly, I bring you recent research that impacts on your health, not just public health, but your health. I'm a firm believer in taking advantage of all the literature that is out there and synthesizing that and bringing that to you in simple, easy to understand format, which we do each week on The Mould Show as part of these live streams.
Thank you very much for watching over the last year. 2020 has been a difficult one, for many reasons. It has brought the spotlight firmly onto all manner of infectious diseases and especially viral-mediated diseases. We're never going to forget 2020, many of you have gotten a news catalyzed lesson in epidemiology and science and infection control. Don't stop looking for answers and questions and working out how you can take advantage of all the information which is out there. I hope you have a wonderful holiday over the next couple of days, stay safe and I'll look forward to seeing you in 2021. And hopefully for all of us, this will be a happy and healthy time. Bye for now. See you next year.
Lei, D. and Grammer, L., 2019. An overview of allergens. Allergy and Asthma Proceedings, 40(6), pp.362-365. https://doi.org/10.2500/aap.2019.40.4247
Berge, M., Munir, A. and Dreborg, S., 1998. Concentrations of cat (Fel d 1), dog (Can f 1) and mite (Der f 1 and Der p 1) allergens in the clothing and school environment of Swedish schoolchildren with and without pets at home. Pediatric Allergy and Immunology, 9(1), pp.25-30. https://doi.org/10.1111/j.1399-3038.1998.tb00296.x
de Vrieze, J., 2020. Suspicions Grow That Nanoparticles In Pfizer’S COVID-19 Vaccine Trigger Rare Allergic Reactions. [online] Science | AAAS. Available at: <https://www.sciencemag.org/news/2020/12/suspicions-grow-nanoparticles-pfizer-s-covid-19-vaccine-trigger-rare-allergic-reactions> [Accessed 21 December 2020].