Relieving concerns that the fall/winter outbreak of H1N1 influenza might peak before a vaccine became widely available, the first batches of the vaccine have now been shipped, and the first patients should begin receiving vaccinations by the end of this week.
In related news, the Department of Health and Human Services also began to release oseltamivir for children from the national stockpile, distributing enough of the liquid formulation of the drug to treat 30,000 pediatric patients. The Food and Drug Administration (FDA) approved use of medication past its expiration date after testing indicated that it was still usable.
Sanofi-Aventis, the maker of an injected killed virus vaccine, was able to finish production nearly 2 weeks earlier than expected, and other manufacturers have also sped up production.
Much of the vaccine to be distributed in the U.S. will be a nasal spray formulation containing live attenuated (weakened) virus. However, this live virus vaccine is not suitable for pregnant women, children under age 2, elderly adults, or people with compromised immune function. These groups should therefore receive the killed or inactivated virus injection.
As previously reported, the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) announced in August which groups are to be given priority for H1N1 vaccination:
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Pregnant women; |
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People who live with or care for children younger than 6 months of age; |
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Healthcare and emergency services personnel; |
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People between the ages of 6 months and 24 years; |
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People between the ages of 25 and 64 years who are at higher risk due to pre-existing chronic health conditions. |
Pregnant women have top priority because they have an increased risk of complications and death related to H1N1 influenza. According to a CDC report released last week, 100 pregnant women with H1N1 flu have been hospitalized in intensive care units and 28 have died during the first 4 months of the outbreak starting this past April.
U.S. military personnel will also be among the first to receive the H1N1 vaccine, which will be mandatory. No other Americans will be compelled by federal law to receive the vaccine, though healthcare facilities and emergency service departments may require their employees to be vaccinated.
To date, people with HIV have not been among those at increased risk for flu complications or death. Nevertheless, HIV positive individuals with a low CD4 cell count should ask their doctor about receiving the vaccine.
As stocks of vaccine become available, they will be distributed to health departments and healthcare providers across the country. Some 6 to 7 million doses are expected to become available this week. CDC director Thomas Frieden indicated that he predicts a "challenging few weeks" as healthcare workers gear up to vaccinate 75 million or more people nationwide by the end of the year.
Research has shown that a single dose of the vaccine -- rather than the 2 doses that had been predicted -- provides adequate protection for most individuals, which effectively doubles the number of people who can be vaccinates with available supplies.
However, there are indications that the vaccine may not be in as high demand as health officials expected. People have expressed a variety of concerns about vaccine ingredients and side effects. One recent telephone survey, for example, found that only 35% of parents said they would definitely have their children vaccinated against the new flu.
The H1N1 vaccines currently being produced are comparable to the 100 million seasonal flu vaccinations given each year, and in fact are purified in the same factories. Studies have shown that the H1N1 vaccine has similar side effects, primarily injection site soreness and mild fever.
The H1N1 flu vaccines being produced in the U.S. do not contain adjuvants, or agents that boost immune response, given that the base vaccine produces good responses on its own. Some other countries, however, are including adjuvants, which enables a given supply of vaccine to be used for more people. Some of the swine flu vaccines now being produced contain a small amount of thimerosal (a mercury-based preservative), but others do not.
This caution on the part of the public suggests that the task for public health officials may shift from allaying panic about unavailable vaccine to encouraging people to receive it -- especially those at greatest risk of adverse H1N1 flu outcomes. Authorities are keen to promote widespread vaccination, as another recent CDC report suggested that 15 states could run out of hospital beds due to the ongoing outbreak.
For further flu newws as it developed, visit the CDC H1N1 influenza web site.
An updated CDC fact sheet, "2009 H1N1 Influenza Shots and Pregnant Women: Questions and Answers for Patients," is available online.
10/06/09
Sources
Kaiser Family Foundation. Injectible H1N1 Vaccine Ships Ahead of Schedule in U.S. Kaiser Daily Global Health Policy Report. September 30, 2009.
Kaiser Family Foundation. First U.S. Patients Could Receive H1N1 Vaccine Next Week. Kaiser Daily Global Health Policy Report. October 2, 2009.
National Partnership for Women and Families. New H1N1 Strain Appears Especially Dangerous in Pregnant Women, CDC Says. Women's Health Policy Report. October 2, 2009.
DG McNeil, Jr. Swine Flu Spread Prompts Move on Vaccine. New York Times. October 2, 2009.
R Knox. What You Need To Know About Swine Flu Vaccine. NPR. October 5, 2009.
