Clostridium tetani, which has been treated with formaldehyde. It is a brownish yellow or slightly turbid liquid, usually having the distinctive odor of formaldehyde. Alum Precipitated Diphtheria and Tetanus Toxoids and Pertussis Vaccines Combined (DPT).— This is a markedly turbid, whitish liquid. It is nearly odorless or may have a slight odor of the preservative. It is a sterile suspension of the precipitate obtained by treating the mixture of diphtheria toxoid, tetanus toxoid, and pertussis vaccine with alum and combining in such proportions as to ensure an immunizing dose of each in the total dosage as listed on the label. Cholera Vaccine.—Cholera vaccine is a suspension of killed cholera, Vibrio comma, in a suitable diluent, usually normal saline. The vaccine presents a turbid appearance, and there may be a slight odor due to the preservative. On storage, autolysis may occur so that the vaccine may become almost as clear as water. Poliovirus Vaccine.—There are two kinds of polio vaccine: Inactivated poliovirus vaccine (IPV), which is the shot recommended in the United States today, and a live, oral polio vaccine (OPV), which consists of drops that are swallowed. Until recently, OPV was recommended for most children in the United States. OPV helped us rid the country of polio, and it is still used in many parts of the world. Both vaccines give immunity to polio, but OPV is better at keeping the disease from spreading to other people. However, for a few people (about one in 2.4 million), OPV actually causes polio. Since the risk of getting polio in the United States is now extremely low, experts believe that using oral polio vaccine is no longer worth the slight risk, except in limited circumstances. Inactivated poliovirus vaccine (IPV) must be stored between 2^BC and 8^BC (24^BF and 46^BF). The vaccine is clear and colorless, and it should be administered intramuscularly or subcutaneously. ORAL POLIOVIRUS VACCINE MUST NEVER BE ADMINISTERED PARENTERALLY. To maintain potency, OPV must be stored in the freezer compartment of the refrigerator. It should be noted that certain forms of this vaccine will remain fluid at temperatures above -14^BC. If frozen, after thawing, agitate the vaccine to ensure homogeneity of its contents before use. Once the temperature rises above 0^BC, the vaccine MUST BE USED WITHIN 7 DAYS. During this period, it must be stored below 10^BC. Yellow Fever Vaccine.—This vaccine is a dull, light orange, flaky or crust-like desiccated mass that requires rehydration immediateley before use. It must be stored at or below 0^BC until rehydration is effected with sterile sodium chloride injection USP. Plague Vaccine.—The vaccine for plague is a sterile suspension of killed plague bacilli in an isotonic solution. The strain of bacilli used has been selected for its high antigenic efficiency. The vaccine is a turbid, whitish liquid with little or no odor. The presence of any precipitate is reason to suspect contamination. Influenza Virus Vaccine.—The influenza virus vaccine is prepared from the allantoic fluid of incubated fertile hen eggs. It is a slightly hazy fluid, the result of minute amounts of egg protein. Its color varies from gray to very faint red, depending upon the method of manufacture. The duration of immunity is probably no longer than a few months, which necessitates repeating the inoculation before the expected seasonal occurrence. Do not inoculate individuals who are known to be sensitive to eggs or egg products, or personnel suffering from upper respiratory infections. Dried Smallpox Vaccine.—This vaccine is prepared directly from calf lymph, purified, concentrated, stabilized, and dried by lyophilization. Dried smallpox vaccine is much more stable than the conventional liquid. When stored at or below 25EC, it retains its full potency for 18 months. When reconstituted and stored below 4EC (preferably 0EC), it retains its full potency for 3 months. Smallpox is no longer considered to be a threat to world health, and immunizations against it are no longer required. However, a general knowledge of the disease and its prevention is important. Anthrax Vaccine.—The anthrax vaccine for humans licensed for use in the United States is a cell-free filtrate vaccine (using dead as opposed to live bacteria). Inspect the vaccine visually for particulate matter and discoloration before administration. Anthrax vaccine should be stored between 2EC and 8EC (refrigerator temperature); it must not be frozen. Do not use the vaccine if the expiration date listed on the package has expired. The vaccine should be administered only to healthy men and women from 18 to 65 years of age. It should NOT be administered to pregnant women. 6-9