Vaccinations or inoculations are excluded as immunizations unless directly
related to the treatment of an injury or direct exposure to a disease or
condition as listed below. Preventive immunizations are not covered except for
the following: pneumococcal, hepatitis B, and influenza virus vaccines. If a
vaccine or inoculation is not covered, related charges are also not covered.
(CMS Pub 100-02 _Medicare Benefit Policy Manual_ , Chapter 15 - Covered
Medical and Other Health Services, Section 50.4.4.2 - Immunizations.)  
  
Each specific immunization has specific coverage criteria.  
The following immunizations are covered post-exposure:

  1. Tetanus, Diphtheria and Pertussis (Tdap) Vaccines and Tetanus Diphtheria (Td) Vaccines  
These injections are covered when given for an acute injury to a person who is
incompletely immunized for tetanus.

    1. Recommendations on tetanus prophylaxis are based on the condition of the wound and the patient's immunization history. 
      1. For more serious wounds, toxoid should be administered if the patient has not had a booster dose within the past 5 years.
      2. A wound with any of the following clinical features is a tetanus-prone wound: more than 6   
hours old; stellate; avulsion; abrasion; greater than 1 cm deep; injury due to
missile, crush,  
burn, or frostbite; signs of infection; devitalized tissue; or a wound which
affords anaerobic  
conditions or which has been incurred in a circumstance with probability of
exposure to  
tetanus spores.

      3. In cases of clean, minor wounds, tetanus toxoid should be administered only if the patient has not had a booster dose within the past 10 years.
    2. When a patient has not received primary immunization, or the primary immunization status is not known, and the patient has sustained a high-risk wound, administration of Tdap is recommended. Administration of Td may be appropriate based on the time since the patient received their last Tdap and the severity of the wound.
    3. When a tetanus booster is given to a patient in the absence of an injury/potential exposure, the injection does not meet the coverage criteria for Medicare (even though it may be appropriate preventative treatment). Preventative services should not be billed to Medicare.
  2. Diphtheria antitoxin will be covered for the treatment of diphtheria. 
  3. Hepatitis A vaccine 

Hepatitis A is an acute, usually self-limiting infection of the liver caused
by hepatitis A virus (HAV). The virus has a worldwide distribution and causes
about 1.5 million cases of clinical hepatitis each year. The disease burden
due to hepatitis A in the United States has been estimated to be approximately
143,000 infections per year, of which 75,800 results in clinical hepatitis.  
Humans are the only reservoir of the organism. Transmission occurs primarily
through the fecal-oral route, and is closely associated with poor sanitary
conditions. The most common modes of transmission include close personal
contact with an infected person and ingestion of contaminated food and water.
The virus is shed in the feces of persons with both asymptomatic and
symptomatic infection. Under favorable conditions HAV may survive in the
environment for months. Blood born transmission of HAV occurs but is much less
common.

The average incubation period is 28 days but may vary from 15-50 days.
Approximately 10-12 days after infection the virus can be detected in blood
and feces. In general, a person is most infectious from 14-21 days before the
onset of symptoms, through 7 days after the onset of symptoms. Once a person
has had Hepatitis A, they have lifetime immunity, so vaccines are unnecessary
for these individuals.

Hepatitis A Vaccine will be covered for those patients who have been exposed
either by close personal contact with an infected person or after ingestion of
contaminated food or water.

Several vaccines against hepatitis A are now available that are highly
efficacious and provide long-lasting protection in adults and in children
above one to two years of age. For those requiring both immediate and long-
term protection, the vaccine may be administered concomitantly with Immune
Globulin (IG).

Immunization for adults, children and adolescents consists of a two-dose
regimen with the second dose being administered 6-18 months later depending on
the vaccine used.  
Examples of the vaccines available are:  
          HAVRIX (Hepatitis A Vaccine, Inactivated)  
          VAQTA (Hepatitis A Vaccine, Inactivated)

  4. Rabies Prophylaxis   
Rabies is a disease that rarely affects humans. It is carried by animals and
transmitted by bite or scratch. The most common carriers are skunks, foxes,
bats, raccoons, or domestic animals that have had infectious encounters with a
carrier. When a human has had an encounter with an animal, the physician can
determine if the encounter was at high risk for rabies exposure.

    1. Post-exposure prophylaxis treatment utilizes two rabies immunizing products concurrently: 
      1. Vaccines - induce an active immune response that requires about 7-10 days to develop but persists for as long as a year or more. Types can include:  
\- Human Diploid Cell Rabies Vaccine (HDCV)  
\- Rabies Vaccine, Adsorbed (RVA)

      2. Globulins - provide rapid passive immunity that persists for a short time (half-life of about 21 days). Types can include:  
\- Rabies Immune Globulin (RIG)  
\- Antirabies Serum, Equine (ARS) - preferred over RIG due to less side
effects than RIG.

    2. Post-exposure injections are given in the following way: 
      1. When the patient has not been previously immunized  
\- RIG; half the dose IM, the other half in the wound (bite), on the day of
the exposure; and  
\- HDCV, IM, on the day of exposure and days 3, 7, 14, and 28.

      2. When the patient has been previously immunized  
\- HDCV on the day of the exposure and day 3.

  5. When immune globulin treatment is administered, see the policy Immune Globulins for coverage criteria. 
  6. **Drug Wastage**  
Medicare provides payment for the discarded drug/biological remaining in a
single-use drug product after administering what is reasonable and necessary
for the patient's condition. If the physician has made good faith efforts to
minimize the unused portion of the drug/biological by how it is supplied; how
patients are scheduled; and how it is ordered, accepted, stored, and used;
Medicare will cover the amount of drug discarded along with the amount
administered.  For further information, refer to national policy: CMS Pub
100-04 _Medicare Claims Processing Manual_ , Chapter 17 - Drugs and Biologics,
Section 40 - Discarded Drugs and Biologicals.

  7. For coverage information regarding vaccinations for Influenza, pneumococcal pneumonia and hepatitis B see:   
CMS Pub 100-04 _Medicare Claims Processing Manual_ , Chapter 18 - Preventive
and Screening Services and CMS Pub 100-02 _Medicare Benefit Policy Manual_ ,
Chapter 15 - Covered Medical and Other Health Services.