- Allergy treatment facts
- Cleaning and More Cleaning: What Really Helps?
- What are great techniques for mold patrol?
- How can people with allergies ideally control the air quality and climate in their homes?
- How can dust covers help?
- What are carpet powders? Can they help?
- What to do with the pets?
- What do I do with those ghastly cockroaches?
Allergy treatment facts
- Avoidance is always the best treatment for allergies.
- There are many easy cleaning methods that can significantly decrease allergies.
- Controlling the air quality and climate of your home can bring you tremendous health benefits.
- If you are going to keep a pet that is a source of allergies, there are measures that you can take to optimize your home environment.
Avoidance is always the best treatment for allergies regardless of which allergens are the triggers. Interestingly enough, the most effective, least expensive, and simplest options are not always followed. Many people choose medications or vaccinations instead, despite their drawbacks. Fortunately, there are lots of simple methods, both old and new, to help with avoidance. Remember, putting into practice any of these measures can only be helpful in managing your allergies.
The good news is that you really don't have to strip your house down to the bare bones to make it allergy proof. Thorough and regular cleaning generally makes a huge difference in keeping your house as mold and dust free as possible. Patients with asthma or allergic rhinitis that are due to dust mites, molds, or other indoor allergens can feel better by taking these simple measures:
- Keep the home cool (between 68 and 72 degrees F);
- Maintain a low humidity (between 40 and 50%); and
- Make certain there is good ventilation.
When patients get started with the process of "allergy-proofing" their homes, one of two things usually happens. They either do nothing or "overdo it." Some patients become so overwhelmed with all the different methods of allergy-proofing that they simply do nothing. That's always a disappointing outcome, especially when the process is so straightforward and inexpensive. Just focusing on the basics of a routine and thorough cleaning and temperature and humidity reduction can lead to fewer symptoms and a vastly improved quality of life.
Sometimes, the opposite occurs. The allergy-proofing process becomes all consuming and inordinately expensive. Overpriced and often inefficient whole-house filtration devices are installed when simple cleaning and reduction of humidity and temperature would have been adequate. Clearly, there are situations in which extreme measures need to be undertaken. Before going down this path, however, it's best to consult with your doctor. Start with the easy things first.
The next section will describe the best steps to take in allergy-proofing your home. Always take a calculated approach, stepping up the process as needed for certain problems. First, we will focus on the best ways to clean and in the second part, on the available technologies.
Cleaning and More Cleaning: What Really Helps?
If you are going to undertake to thoroughly clean your home, it is best to ensure at the beginning that the techniques being used are the most effective. The tips discussed below will help you achieve the maximum benefit for all of your efforts.
Soap & Hot Water: Scientific studies of patients who are allergic to dust mites have shown that taking steps to minimize dust mite allergens in the bedroom leads to a decrease in allergic symptoms and medication requirements. Emphasis is placed on the bedroom since people spend at least one third of a 24 hour day there. It is also the room with the greatest number of dust mites.
New synthetic bedding materials are available that are equivalent to down for warmth but can withstand washing more easily because the fibers don't clump. The ideal water temperature for washing is at least 130 degrees F to completely kill the dust mites found throughout the bedding.
When the hot water heater is set to achieve a temperature of 130 degrees F, precautions must be taken to prevent scalding a child. For example, at bath time, always remain in the room with a child and make sure to always turn off the "hot" water faucet first and finish with the "cold" faucet.
The choice of bedding materials becomes important. They must be able to withstand the rigors of weekly hot water washing in order to kill the dust mites and remove accumulated allergens. Many bedding materials may be bulky, making them more difficult to wash. It may be easier to use several layers for warmth instead of bulky items for ease of washing. Since any type of blanket material can support dust mite growth, it is important to select one that can withstand repeated washings.
Vacuuming the Right Way: If the carpet can't be replaced by a solid surface such as linoleum or hardwood, then it must be cleaned thoroughly and frequently. Also remember to vacuum upholstered furniture, draperies, and other fabric items that cannot be washed, removed, or replaced. The trouble with vacuuming is that the allergenic dust mite and mold particles become airborne during the process. Dust mite particles can remain airborne for about 15 minutes and be redistributed throughout the home environment. Allergic persons clearly should not be doing the vacuuming and should also stay out of the area until the dust particles resettle. Dust mite particles also become airborne during bedding changes or the placement of dust covers on the mattress, box spring, and pillows. For severely allergic people, these tasks can lead to significant allergy and possible asthma attacks. Those affected by these allergies should definitely not perform these chores.
Allergic persons should not perform vacuuming tasks and should keep out of the immediate environment for at least 1 hour after the vacuuming has been completed. Damp dusting should then follow to catch any loose particles.
The vacuum cleaner collecting bag acts as the primary filter in most vacuum cleaning systems. A standard bag can be replaced with a high-filtration multi-layer bag and an exhaust filter can be added. These measures prevent the allergen particles from escaping and becoming airborne during the vacuuming process. Replacing the vacuum bags and adding exhaust filters are economical ways to increase the efficiency of an older vacuum. These bags and filters are easily obtained from allergy supply houses. The filters are available in 8" x 10" sheets that can be cut to size for any canister vacuum. Very expensive vacuum units with built-in HEPA systems (High Efficiency Particulate Air-filter) have been available for years. Now, more affordable brands of vacuums come equipped with HEPA filters and a removable canister that can be washed in the top rack of the dishwasher. This system eliminates the problem with vacuum bags. As the older generation of vacuums is phased out, this development should be quite helpful in allergy control. Whole-house vacuum systems, although quite expensive, are also helpful because the dirt collection system is located outside of the house, usually in the garage.
Hard Surfaces Are Easier to Clean Dust mites, molds, animal danders, and insect debris are difficult to thoroughly clear from the environment. However, it really is easier and quicker to clean a hard surface such as wood, tile, vinyl, or leather than it is to clean all those nooks and crannies found in carpet, fabric, or other soft surfaces.
Replacing the carpet with a hard-surfaced floor can eliminate over 90% of dust mites. If you absolutely have to have carpet, get the kind that has a low pile.
The following is a list of suggestions for how to make allergy-proofing an easier task. Hopefully, these ideas will lead to other methods you can use to thoroughly clean and maintain your environment allergy free. Take it one step at a time and focus on the bedrooms first. If you plan on moving, pay close attention to steps that can be taken to allergy-proof prior to moving into the new house. It is much easier to put these ideas into action in the beginning than after everything is in place. It's really not as hard as it looks!
- Avoid ornate furniture. Plain, simple designs accumulate less dust. No open bookshelves; they are great dust-catchers.
- Keep all clothes in drawers or closets, never lying about the room. Enclose wool clothes in plastic zipper bags. Avoid mothballs, insect sprays, tar paper, or camphor. Keep drawers and closet doors closed.
- Remove as much clutter as possible to make cleaning easier. Place hard-to-clean items in closets, drawers, or display cabinets with glass doors.
- When choosing furnishings, it is best to go with wood, leather, vinyl, or rubberized canvas furniture and avoid upholstered pieces. Upholstery easily traps allergens and is much harder to clean. You might try washable slipcovers on existing upholstered furniture.
- Install wood, tile, or linoleum flooring. Limit throw rugs to those that can be easily cleaned in the washer. They should be able to withstand washing weekly.
- Use allergen-proof encasings for pillows, mattresses, and box springs. Tape over zippers to help prevent leaks. Vacuum all casings frequently. Store nothing under the bed.
- Use washable cotton or synthetic blankets, not fuzzy surfaced ones. Use easily laundered cotton bedspreads or coverlets; avoid chenille.
- Install roll-up washable cotton or synthetic window shades. Avoid venetian blinds, mini-blinds, and pleated shades.
- Use washable cotton or fiberglass curtains. Avoid draperies and decorative fabric window treatments!
- Install central air conditioning or window units. Keep windows closed, especially during periods of high pollen counts and windy conditions. Grasses, weeds, and trees tend to pollinate during the early morning hours. Sleep with the windows closed.
- Use Dacron or other synthetics for pillows. Avoid feathers or foam rubber, which traps moisture and promotes mold and dust mite growth.
- Space heaters are preferred over hot air ducts. In homes with forced air heat, use filters or damp cheesecloth over inlets to reduce dust circulation. Change every two weeks. Consult your physician about air purifiers. Keep beds away from air vents.
- Damp dusting using a dampened cloth or an oiled mop will minimize the distribution of dust through the air.
Baby's Room - Special Tips: It's a good idea to eliminate potential irritants and allergens from your baby's environment. Here's what you can do to help eliminate potential sources of allergens from your baby's world.
- Wood or plastic chairs are best for baby's room.
- Again, avoid all feather bedding.
- Use dust-proof casings for all bedding.
- Stuffed animals should never be placed in the crib and, if used, should be washable. Put most of the stuffed items in a closed chest or closet. Store them in a freezer bag when not in use.
- When it comes to gifts for children, ask for books rather than stuffed animals. Keep the books in a bookcase with doors to help reduce allergens.
- Humidifiers should be reserved for croup. They should not be used routinely since they increase the dust mite and mold counts. If a humidifier is required, the cool water variety is safer than a steam humidifier in terms of burns. Also, be sure to change the water daily if a humidifier is necessary.
- Animal fur is a potential allergen. It's best to keep pets out of the baby's room.
- Overhead mobiles and wall hangings collect dust!
- Baby bumpers should be simple and washable. No ruffles or pleats.
- Ruffled curtains and venetian blinds collect a lot of dust. Vertical blinds are preferable. If levelers or shutters are used, be sure to clean them weekly with a damp cloth.
- The crib should be placed away from air vents.
- A HEPA filter (High Efficiency Particulate Air-filter) can be placed under the crib. The filter will help to decrease airborne allergens such as pollens, mold spores, and animal danders.
What are great techniques for mold patrol?
Greenhouses, antique shops, saunas, sleeping bags, summer cottages and hotel rooms are sources of increased mold exposure. Automobile air conditioners may harbor mold.
Numerous cleaning products specializing in mold control are available. The active ingredients in these products that are effective against molds are bleach and ammonia. So why should you pay a premium for anti-mold preparations when you can readily prepare the mixture at home for a fraction of the cost? As long as you are aware of the fabric fading effects and the potentially caustic nature of these cleaning materials, there should be no problems. Limited areas of mold collection (as occurs in the bathroom) can be cleaned with a bleach solution. An old toothbrush and bleach work wonders on the dark mildew that often collects between the tiles. If there is carpet in the bathroom (ideally there shouldn't be since this is a "moisture trap" for mold), be careful not to drip the bleach on the carpet! Regularly using a "squeegee" along with a bottle of dilute bleach will help keep the mold spores under control.
Shower curtains present a special problem for mold control. Once the curtain is stained with mold spots, it might be worth a wash and rinse cycle with bleach. Usually, however, by the time you can see dime-size deposits of mold on the plastic shower curtain, it's probably not worth the effort. At this point, it would be better to purchase a vinyl curtain with a mold inhibitor. (These are available for use in motel rooms.)
Larger areas, especially under the house, should be treated with either Orthocine, Captan's powder (8 oz in a gallon of water), or bleach (mix 1 cup of bleach to 1 gallon of water). These products are available in hardware stores. Using rubber gloves, scrub the affected areas and repeat the process in 2 hours.
For even more extensive molds under the house, buy a 5 lb. bag of Bordeaux mixture (mostly copper sulfate) from any regular nursery and mix it with 15 to 20 gallons of water in a large tank sprayer. Spray the areas under the house, the ground, and all wood thoroughly at least 3 to 4 times a year for the first several years.
If the Bordeaux mixture is unavailable or does not control the problem, Ziram can be used in a 1-2% spray solution. Mix 3 ounces of the concentrate to 1 gallon of water. Ziram can also be used in the home for walls and floors. When applied to some fabrics, it may produce a slightly yellow color. Protective clothing should always be used when spraying this fungicide. One application of Ziram is usually sufficient for mold control.
Caution: DO NOT STORE FUNGICIDES NEAR FIRE OR OPEN FLAMES. ALWAYS BE SURE THERE IS GOOD VENTILATION DURING USE BECAUSE MANY OF THESE SUBSTANCES ARE TOXIC!
Indoor Mold Control - Other Measures
- Lower the humidity level in the house.
- Use fans for proper ventilation.
- Clean visible mold from walls and ceilings.
- Keep firewood outside since the bark is covered with mold.
- Add mold inhibitor to paint before applying if it will be used in a damp environment, especially on brick and cinderblock walls in a basement or shady areas.
- Mold tends to grow in closets, as they tend to be dark and damp. Dry shoes and boots before storing. Consider a chemical moisture remover (desiccant) such as calcium carbonate flakes or crystals. One brand is Dri-Out Dome, which is readily available through allergy catalogs and home improvement stores.
- Do not carpet the bathroom.
- Mold grows in refrigerators. Keep them clean and defrosted. Remove spoiled food, preferably before it gets that way!
- Correct seepage or flooding problems and remove water-damaged carpet.
- Carpet and pad should not be laid on a concrete floor since this is a great place for moisture to accumulate, resulting in a flourishing population of dust mites and mold.
- Remove moldy stored items from the basement and keep it clean.
Farmers, gardeners, bakers, brewers, florists, carpenters, mill workers, upholsterers, and paper hangers have an increased exposure to mold due to their occupations. Your allergist can offer specific recommendations for handling these work environments.
How can people with allergies ideally control the air quality and climate in their homes?
Controlling the air quality and climate of your home may sound daunting, but it is actually not that difficult to achieve and can lead to substantial benefits. Good maintenance of these systems can increase the benefits you will receive and prolong the life-span of these devices.
HEPA Filters: HEPA stands for High Efficiency Particulate Air-filter. These devices were developed during the Apollo era of space exploration. They can filter most substances from the air, down to 0.3 microns in size. (A micron is a unit of length equivalent to 1/1000 of a millimeter.) They are helpful in filtering pollen, mold spores, animal dander, and fumes.
HEPA filters aren't for dust mites. Dust mite allergens are heavy and fall to the ground quickly, thus avoiding being trapped by HEPA filters.
It is important to remember that you can not filter the world. In other words, you need to run these filters with the windows closed. The size of the room also needs to be taken into consideration when deciding what size HEPA filter to purchase.
HEPA filters have become increasingly available in many discount home improvement stores. Previously, these devices had been primarily available through allergy supply companies and catalogs at a premium price. Now, you can do some comparative shopping before you buy. Other factors to consider before buying include the required interval between changing filters, the ease of obtaining replacement filters, and warranties. One critical factor in the use of HEPA filters is the noise level generated. Many people stop operating the unit due to the "white noise" associated with the device. Make sure that you listen to the device before you purchase it. The good news is that the newer generation of filters is much quieter.
Another type of filter is the electrostatic filter. So far, these have not been shown to be as efficient as the HEPA filter.
An important point to make here is that HEPA filters are not the ultimate solution to the problem of indoor allergens. They can help to some degree but in no way do they replace cleaning, temperature and humidity reduction, clutter removal, and avoidance of allergens such as pet dander.
Dehumidifiers & Humidifiers: Remember, house mites require high humidity to thrive. Dehumidifying the air is easily accomplished with an air conditioner, but this is practical only in hot weather. The correct placement and use of fans and vents can help reduce humidity as can a dehumidifier machine. It pays to find a knowledgeable sales source that can help you determine the appropriate size machine needed for your individual home or office. Clearly, the most important point about a dehumidifier is that it must be kept scrupulously clean. Otherwise, molds will flourish in the collection chamber making your problem worse than it was in the first place. Dehumidifiers must be cleaned daily. Some models have automatic shut off mechanisms that keep the tank from overflowing and some have a continuous drainage system.
Humidity gauges are readily available at any hardware store. A range of 40-50% humidity is good. Humidity lower than 35% can make breathing uncomfortable for some people with asthma or other respiratory conditions. Generally speaking, low humidity is not the health problem that high humidity can be.
Humidifiers are rarely needed except for children with croup. In most parts of the country, the humidity seldom drops below 35% and the nostrils and airways provide natural moisture. However, it is true that in certain parts of the country, a well heated home can become overly dry.
Croup is a viral infection in small children that is characterized by a harsh, barking cough. The condition is frequently worse at night. One of the recommended treatments is mist or steam, which is best provided by a cool air humidifier. Vaporizers should be avoided due to the risk of burns.
As previously noted, some central hot-air systems may include built-in humidifiers that can make the air more comfortable to breathe. However, there are definite problems with this type of system. Not only can these units blow mold spores and dust all through the air, but keeping these systems mold and bacteria free is extremely difficult.
Stand-alone humidifiers are available and are frequently used in homes with antiques or fine art that could be damaged from excessive dryness. They are often recommended for people with respiratory problems and eczema, which can be worsened by dryness. The truth is, though, that humidifiers tend to cause more problems than they solve. They should be used only sparingly, as their health benefits are primarily limited to infants or young children with croup.
The most frequently used stand alone unit is the evaporative humidifier. This system uses a wick or pad to absorb water from a reservoir. A fan then disperses the water vapor through the air. This method can cause bacterial counts in the air to skyrocket, leading to "humidifier fever," a flu-like infection of the respiratory tract.
Although ultrasonic humidifiers kill the bacteria, they also spray parts of the dead microorganisms into the air along with minerals that then deposit on surfaces throughout homes. A fine white dust on furniture evidences these mineral deposits. Generally, the ultrasonic models are no longer distributed but these devices are kept for years, so be sure to check what type of model you might own. A newer type of device is a vibratory humidifier that doesn't cause mineral deposits. All humidifiers should be used sparingly and MUST be cleaned after each use to prevent the rapid growth of bacteria and mold spores. Just by lowering the temperature of the home during the winter, the air will contain more moisture and the need for humidifiers will be minimized.
Air Conditioning & Heating Systems: Air conditioners are critical in filtering summertime air for patients allergic to molds and pollens. They also function as excellent dehumidifiers, thus limiting the growth of dust mites and molds. Another unexpected benefit is that the airflow discourages cockroaches since they prefer non-ventilated spaces.
Filters on both central and window units require frequent changing and or cleaning to remain efficient and prevent mold growth.
Separate room or area filtration units are more effective than whole house filtration units that are installed on central air systems. Claims that an entire house can be adequately filtered with just one unit are false. A HEPA filter can only cover a certain number of cubic feet and separate units need to be installed throughout the system.
Central air-conditioning and heating systems may also come with electrostatic filters that catch smaller particles than regular filters. The filters charge the particles in the air as they pass through the filter. The charged particles are then trapped by an oppositely charged plate in the unit. These devices must be cleaned frequently as well.
A concern about electrostatic filters has been ozone production, which can make asthma worse. This hazard has been reduced by the addition of charcoal filters.
Unfortunately, it is not clear whether the special filters available for home heating and air-conditioning units are completely effective. Be sure to inquire about the particle size that the filter is guaranteed to trap. A minimum of 5 microns is recommended. At this point, it appears that of the two options, HEPA filtration is superior.
Another option is the placement of individual filters over the outlet ducts themselves. These filters should be cleaned weekly and replaced as necessary. They are readily available from most allergy supply stores and catalogs and home hardware stores.
Some forced-air heating systems come with built-in humidifiers. This feature can backfire because dust particles are stirred up by the hot air and mold can flourish in the humidifier itself. Cleaning these units is of the utmost importance, but this can be a cumbersome task. If mold is a problem, it's probably best to have the humidifier removed.
Options apart from forced air systems include space heaters and radiant-heat systems. These two methods of heating are advantageous in that allergens and irritants are not distributed throughout the home environment as they are with forced air systems.
How can dust covers help?
People with allergies to dust mites and molds are well served by encasing their pillows, mattress, and box springs in zippered, allergen-impermeable encasings. These covers provide the patient with a protective barrier against dust mites, their fecal particles, and mold antigens. This is critical in reducing your dust mite exposure especially if you take into account that most people spend at least one-third of each day in the bedroom. The bedroom is also a haven for dust mites due its warmth and humidity and to the abundant food source from human skin flakes and secretions.
Formerly, dust covers were only available in plastic. Fortunately, the technology has improved to the point that the newer fabrics allow airflow but completely prevent the passage of antigens through the impermeable fibers. The flow of air and perspiration through the fabric provides excellent comfort without the clammy feel associated with plastic. These products are increasingly available through various allergy catalogs, allergy supply houses, home supply stores and an ever-increasing number of online computer sites. Grocery store chains are increasingly carrying these products as awareness of their effectiveness has grown. Be sure to examine the samples available so you will be comfortable with your product choice. There is a range of prices for these products, so be sure to compare. Your allergist will typically have an array of catalogs and order forms to assist you in your search.
When people invest in dust covers, they sometimes omit the purchase of the box spring cover in an effort to economize. Since the body is not in direct contact with the box spring, people might think it is not important enough to bother with. Unfortunately, it's not that simple. Several years ago, a study compared the dust mite counts of beds with partial versus complete coverings. It was quite clear that unless all parts are covered, the entire bed becomes reinfested with dust mites in a short period of time. The good news is that you can use a less expensive vinyl cover on the box spring since it does not touch the skin. The investment in complete dust covers is well worth the money.
Researchers in Spain recently found that children sleeping in the bottom and top bunks of bunk beds were equally likely to develop allergy to dust mites. However, the child sleeping on the bottom bunk was at a significantly higher risk of developing asthma than the child on the top bunk. It may be that the health aspects of bunking together should be considered when planning children's room designs, especially for families with asthma and allergy histories.
What are carpet powders? Can they help?
One option is tannic acid (3% solution). Although the acid doesn't kill the dust mites, it does destroy the mite allergens. The solution can be easily sprayed on troublesome surfaces and is fast acting. It may, however, cause staining of carpets and upholstery. On a positive note, tannic acid may inactivate cat allergens, but this requires frequent application. Unfortunately, tannic acid has a temporary effect at best.
Another option is an "acaracide," which comes as a powder or spray that actually kills the dust mites and decreases the antigen levels. This product is available through allergy supply companies, but remains unavailable in Canada.
The presence of a smoker in the home will sabotage the best of all possible treatment programs for allergies and asthma. If you, your spouse or partner, or your child have chronic allergies or asthma problems, don't smoke and don't allow smoking in the home. Smoking may be the reason why allergy and asthma symptoms are persisting despite an otherwise thorough allergy control and medication treatment program. Children who are exposed to cigarette smoke are at a 50% increased risk of developing asthma. There are no excuses and "smoking outside" is not good enough. If you smoke, quit now. It's terrible for you and for everyone who lives with you.
What to do with the pets?
This is frequently a challenging issue for both doctors and allergy sufferers. Common sense and emotion often collide and differences of opinion amongst family members may complicate the problem. In order of their effectiveness, the recommended control measures for a significantly allergic or asthmatic individual are:
- Find another home for the pet.
- Keep the pet outdoors at all times. Remember, though, that the allergens will come into your home on your clothes.
- Keep the pet out of the allergic person's bedroom at all times.
Even after you have found a new home for your pet, animal allergens may still persist in your home for many months in the typical reservoirs, carpeting, upholstery, and mattresses. Repeated vacuuming, steam cleaning, and applications of 3% tannic acid solution will help neutralize the remaining allergens.
If parting with your pet is unacceptable, the following are additional tips for managing the home environment.
- When the pet is indoors, keep it in a room with few allergy reservoirs, such as the kitchen.
- Provide your cat or dog with its own bed.
- Use a HEPA filter in the bedroom and a portable room heater if needed. Seal off the room air ducts.
- Wear a mask when handling the litter box, or even better, have a non-allergic family member do it.
- Vacuum with a double filter or a HEPA filter.
- Wash the cat weekly to help remove surface allergens.
Kittens take to regular bathing better than do older cats. Start slowly with a few drops of tepid water (soap is not necessary) on its fur and then progress to a full rinse. Reward the cat with treats - this might help.
What do I do with those ghastly cockroaches?
Elimination of cockroaches is best accomplished by using a professional exterminator. However, this is only the first step. After the cockroaches have been eliminated, the areas they inhabited must be thoroughly cleaned since their residual debris is highly allergenic. Entry points should be sealed to prevent re-infestation. Use covered trash bins and empty then frequently. Do not store cardboard boxes, newspapers, grocery bags, or empty cans and bottles in your home as they can serve as breeding areas.
Effectiveness of Avoidance Measures
Allergen - Dust Mites
- Most Effective
- Dust Covers
- Weekly hot water washing of bedding
- Carpet Removal
- Keep rooms cool and dry
- Possibly Effective
- Chemical treatment of carpet
- Least Effective
- Air duct cleaning
- Special vacuum cleaners
- Air filters
Allergen - Cockroaches
- Most Effective
- Extermination with regular cleaning
- Possibly Effective
- Elimination of food and water sources
- Least Effective
- Extermination without regular cleaning
Allergen - Cats
- Most Effective
- Complete removal of cat
- Possibly Effective
- Move cat outdoors
- Least Effective
- Air filters
- Carpet cleaners
- Cat washing
Medically reviewed by Michael Manning, MD; American Board of Allergy & Immunology