Immunizations - Smallpox

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Due to the urgency of the H1N1 situation, and the late emergence of the virus in the spring of 2009, manufacturers of the seasonal flu vaccine shifted their efforts to manufacturing the H1N1 vaccine, resulting in shortages of both flu vaccines in 2009.

While in 2009, the H1N1 vaccine was released as a separate immunization, it is now included as one of the three virus strains in the 2010-11 seasonal flu vaccine. A separate H1N1 or swine flu vaccine is not needed and is not available.

The World Health Organization (WHO) recommended the following three viruses in the 2010-11 seasonal flu vaccine:

A/California/7/2009 (H1N1) - like virus,
A/Perth/16/2009 (H3N2) - like virus, and a
B/Brisbane/60/2008 - like virus.

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There are two types flu vaccines/delivery systems. One is given as an injection, the other is a nasal spray.

The flu injection contains killed (inactive) viruses. It is not possible to get the flu from this type of vaccine. The flu injection is approved for people age 6 months and older. A preservative-free vaccine (Fluzone) is also available.

The Nasal spray flu vaccines use a live, weakened virus instead of a dead one.

It is engineered to multiply in the cool temperatures of the nasal passages, but not in the warmer lungs and lower airways. Its presence in the nasal passages boosts the specific immune factors in the mucous membranes that fight off the epidemic flu viruses.
It is approved for healthy people ages 2 - 49, who are not pregnant. It should NOT be used in those who have asthma or in children under age 5 who have repeated wheezing episodes.

The avian flu vaccine is designed for people aged 18 - 64 who are at risk for exposure to the avian H5N1 virus. The vaccine is given as 2 doses, spaced about 1 month apart. In studies, the vaccine appeared to be effective and well tolerated. Currently, the government is stockpiling the vaccination in case of an avian influenza outbreak. The vaccine is not available to the general public.

Timing and Effectiveness of the Vaccine

Ideally, appropriate candidates should be vaccinated every October or November. However, it may take longer for a full supply of the vaccine to reach certain locations. In such cases, the high-risk groups should be served first.

Antibodies to the flu virus usually develop within 2 weeks of vaccination, and immunity peaks within 4 - 6 weeks, then gradually wanes.