The period of protection afforded by a successful vaccination is uncertain, because it varies with different individuals. In a general way immunity for about four or five years is thus secured; ten or twelve years after vaccination the protection is certainly lost and smallpox may be then acquired. Every individual should be vaccinated between the second and third month after birth, and between the ages of ten and twelve, and at other times whenever an epidemic threatens. An unvaccinated person should be vaccinated and revaccinated, until the result is successful, as immunity to vaccination in an unvaccinated person is practically unknown. When unsuccessful, the vaccine matter or the technique is faulty. A person continuously exposed to smallpox should be vaccinated every few weeks—if unsuccessful, no harm or suffering follow; if successful, it proves liability to smallpox. A person previously vaccinated successfully may "take" again at any time after four or five years, and, in event of possible exposure to smallpox, should be revaccinated several times within a few weeks—if the vaccination does not "take"—before the attempt is given up. An unvaccinated person, who has been exposed to smallpox, can often escape the disease if successfully vaccinated within three days from the date of the exposure, but is not sure to do so.
Diseases are not introduced with vaccination now that the vaccine matter is taken from calves and not from the human being, as formerly. Most of the trouble and inflammation of the vaccinated part following vaccination may be avoided by cleanliness and proper care in vaccinating.
In the absence of a physician, vaccination may be properly done by any intelligent person when the circumstances demand it. Vaccination is usually performed upon the outside of the arm, a few inches below the shoulder, in the depression situated in that region. If done on the leg, the vaccination is apt to be much more troublesome and may confine the patient to bed. The arm should be thoroughly washed in soap and warm water, from shoulder to elbow, and then in alcohol diluted one-third with water. When this has evaporated (without rubbing), the dry arm is scratched lightly with a cold needle which has previously been held in a flame and its point heated red hot. The point must thereafter not be touched with anything until the skin is scratched with it. The object is not to draw blood, but to remove the outer layer of skin, over an area about one-fourth of an inch square, so that it appears red and moist but not bleeding. This is accomplished by very light scratching in various directions. Another spot, about an inch or two below, may be similarly treated. Then vaccine matter, if liquid, is squirted on the raw spots, or, if dried on points, the ivory point is dipped in water which has been boiled and cooled, and rubbed thoroughly over the raw places. The arm must remain bare and the vaccination mark untouched until the surface of the raw spot is perfectly dry, which may take half an hour. A piece of sterilized surgical gauze, reaching halfway about the arm and kept in place with strips of adhesive plaster (or an absolutely clean handkerchief bound about the arm, and held by sewing or safety pins), ought to cover the vaccination for three days. After this time the sore must only come in contact with soft and clean old cotton or linen, which may be daily pinned in the sleeve of the under garment. If the scab is knocked off and an open sore results it should be treated like any wound.
If the vaccination "takes," it passes through several stages. On the third day following vaccination a red pimple forms at the point of introduction of the matter, which is surrounded by a circle of redness. Some little fever may occur. On the fifth day a blister or pimple containing clear fluid with a depressed center is seen, and a certain amount of hard swelling, itchiness, and pain is present about the vaccination. A sore lump (gland) is often felt under the arm. The full development is reached by the eighth day, when the pimple is full and rounded and contains "matter," and is surrounded by a large area of redness. From the eleventh day the vaccination sore dries, and a brown scab forms over it about the end of the fourteenth day, and the redness and swelling gradually depart. At the end of about three weeks the scab drops off, leaving a pitted scar or mark. Not infrequently the vaccination results in a very slight pimple and redness, which passes through the various stages described, in a week or ten days, in which case the vaccination should be repeated. Unless the vaccination follows very closely the course described, it cannot be regarded as successful, although after the first one or two vaccinations the result is often not so severe, and the time of completion of the various stages somewhat shortened.
Rarely an eruption, resembling that at the vaccination site, appears on the vaccinated limb and even becomes general upon the body, due to urticaria or to inoculation, through scratching.
The special treatment of an attack of smallpox is largely a matter of careful nursing. A physician or nurse can scarcely lay claim to any great degree of heroism in caring for smallpox patients, as there is no danger of contracting the disease providing a successful vaccination has been recently performed upon them. The patient should be quarantined in an isolated building, and all unnecessary articles should be removed from the sick room, in the way of carpets and other furnishings. It is well that the room be darkened to save irritation of the eyes. The diet should be liquid: milk, broths, and gruels. Laudanum, fifteen drops, or paregoric, one tablespoonful in water, may be given to adults, once in three hours, to relieve pain during the first few days. Sponging throughout the course of the disease is essential; first, with cool water, as directed for scarlet fever, with the use of cold on the head to relieve the itching, fever, and delirium. The cold pack is still more efficient. To give this, the patient is wrapped in a sheet wrung out in water at a temperature between 68° and 75° F. The sheet surrounds the naked body from feet to neck, and is tucked between the legs and between the body and arms; the whole is then covered with a dry blanket, and a cold, wet cloth or ice cap is placed upon the head. The patient may be permitted to remain in the pack for an hour, when it may be renewed, if necessary, to allay fever and restlessness; otherwise it may be discontinued. The cold sponging or cold pack are indicated when the temperature is over 102.5° F., and when with fever there are restlessness and delirium. Great cleanliness is important throughout the disease; the bedclothes should be changed daily and the patient sponged two or three times daily with warm water, unless fever is high. Cloths wet with cold carbolic-acid solution (one-half teaspoonful to the pint of hot water) should be kept continuously on the face and hands. Holes are cut in the face mask for the eyes, nose, and mouth, and the whole covered with a similar piece of oil silk to keep in the moisture. Such applications give much relief, and to some extent prevent pitting. The hair must be cut short, and crusts on the scalp treated with frequent sponging and applications of carbolized vaseline, to soften them and hasten their falling. The boric-acid solution should be dropped into the eyes as recommended for measles, and the throat sprayed every few hours with Dobell's solution. Diarrhea in adults may be checked with teaspoonful doses of paregoric given hourly in water. Vaseline and cloths used on a patient must not be employed on another, as boils are thus readily propagated. All clothing, dishes, etc., coming in contact with a patient must be boiled, or soaked in a two-per cent carbolic-acid solution for twenty-four hours, or burned. When the patient is entirely free from scabs, after bathing and putting on disinfected or new clothes outside of the sick room, he is fit to reënter the world.
CHICKENPOX.—Chickenpox is a contagious disease, chiefly attacking children. While it resembles smallpox in some respects, at times simulating the latter so closely as to puzzle physicians, it is a distinct disease and is in no way related to smallpox. This is shown by the fact that chickenpox sometimes attacks a patient suffering with, or recovering from, smallpox. Neither do vaccination nor a previous attack of smallpox protect an individual from chickenpox. Chickenpox is not common in adults, and its apparent presence in a grown person should awaken the liveliest suspicion lest the case be one of smallpox, since this mistake has been frequently made, and with disastrous results, during an epidemic of mild smallpox. One attack of chickenpox usually protects against another, but two or three attacks in the same individual are not unknown. The disease may be transmitted from the patient to another person from the time of the first symptom until the disappearance of the eruption. The disease ordinarily occurs in epidemics, but occasionally in isolated cases.
Development.—A period of two weeks commonly elapses after exposure to the disease before the appearance of the first symptom of chickenpox, but this period may vary from thirteen to twenty-one days.
Symptoms.—The characteristic eruption is often the first warning of chickenpox, but in some cases there may be a preliminary period of discomfort, lasting for a few hours, before the appearance of the rash; particularly in adults, in whom the premonitory symptoms may be quite severe. Thus, there may be chilliness, nausea, and even vomiting, rarely convulsions in infants, pain in the head and limbs, and slight fever (99° to 102° F.) at this time. The eruption shows first on the body, in most cases, especially the back. It consists of small red pimples, which rapidly develop into pearly looking blisters about as large as a pea to that of the finger nail, and are sometimes surrounded by a red blush on the skin. These blisters vary in number, from a dozen or so to two hundred. They do not run together, and in three to four days dry up, become shriveled and puckered, and covered with a dark-brown or blackish crust, and drop off, leaving only temporary red spots in most cases. The fever usually continues during the eruption. During the first few days successive fresh crops of fresh pimples and blisters appear, so that while the first crop is drying the next may be in full development. This forms one of its distinguishing features when chickenpox is compared with smallpox. In chickenpox the eruption is seen on the unexposed skin chiefly, but may occur on the scalp and forehead, and even on the palms, soles, forearms, and face. In many cases the eruption is found in the mouth, on its roof, and the inside of the cheeks. The blisters rarely contain "matter" or pus, as in smallpox, unless they are scratched. Scratching may lead to the formation of ugly scars and should be prevented, especially when the eruption is on the face. Pitting rarely occurs.
Determination.—The discrimination between chickenpox and smallpox is sometimes extremely puzzling and demands the skill of an experienced physician. When one is unavailable, the following points may serve to distinguish the two disorders: smallpox usually begins like a severe attack of grippe, with pain in the back and head, general pains and nausea or vomiting, with high fever (103° to 104° F.) These last two or three days, and may completely subside when the rash appears. In chickenpox preliminary discomfort is absent, or lasts but a few hours before the eruption. The eruption of smallpox usually occurs first on the forehead, near the hair, or on the palms of the hands, soles of the feet, the arms and legs, but is usually sparse on the body. The eruption appears about the same time in smallpox and not in successive crops, as in chickenpox. Chickenpox is more commonly a disease of childhood; smallpox attacks all ages. The crusts in chickenpox are thin, and appear in four or five days, while those of smallpox are large and yellow, and occur after ten or twelve days.