What to know about getting H1N1 vaccine
Next week, the long-awaited H1N1 vaccine is expected to arrive. At least three of the four vaccine makers have begun shipping their products to undisclosed distribution centers.
There are two types of the vaccine available: the flu shot, an inactivated vaccine containing fragments of killed influenza virus, and a nasal spray, which is made using a weakened live flu virus. The nasal spray will most likely be the first to be widely distributed, however certain groups, including pregnant women, young children and people with compromised immune systems, cannot receive the nasal spray.
So far officials of the National Institutes of Health say that in clinical trials they've seen no serious side effects and that study subjects who have been immunized have generated a good response.
The Centers for Disease Control and Prevention recommends the vaccine for certain high-priority groups because they are more likely to have serious complications if they develop swine flu. These groups include: pregnant women; caregivers and household contacts of children younger than 6 months; everyone between the ages of 6 months and 24 years; and people ages 25 to 64 with existing health problems.
Even people who are not in these groups can get the vaccine. But now the vaccine is almost here, the question is, "Do you want it?" We looked through our Empowered Patient inbox and it turns out that many of our readers still have questions. We consulted a team of experts to get their answers, which are edited for brevity and clarity.
Production and availability of pandemic influenza A (H1N1) vaccines
Is a vaccine against pandemic influenza A (H1N1) virus available to immunize people?
No, but work is well under way to develop such a vaccine. Making new influenza vaccines ready to immunize people generally takes five to six months after first identification of the pandemic virus. The pandemic influenza A (H1N1) 2009 virus was identified at the end of April 2009.
How quickly will pandemic influenza A (H1N1) vaccines be available for use?
The very first doses of influenza A (H1N1) vaccine usable to immunize people, from one or more manufacturers, are expected as early as September 2009.
What implications does the declaration of a pandemic (phase 6) have on influenza vaccine production?
When the WHO Director-General declared the influenza A (H1N1) pandemic on 11 June 2009, she noted that production of seasonal influenza vaccines would be completed soon and that full industrial production capacity would then be available to ensure the largest possible supply of pandemic vaccine in the months to come.
Which manufacturers will make pandemic influenza A (H1N1) vaccines?
There are currently around twenty vaccine manufacturers with licenses to produce seasonal influenza vaccines. There are other qualified vaccine manufacturers who are preparing to make influenza A (H1N1) vaccine, but do not yet have a licensed seasonal influenza vaccine.
What is the global manufacturing capacity for a potential influenza A (H1N1) pandemic vaccine?
Based on a global survey made by WHO on 15 May 2009, a maximum of 4.9 billion doses potentially could be produced in 12 months, but only if several assumptions are met. First, full global manufacturing capacity is devoted to this production. Second, production yields for influenza A (H1N1) vaccine are similar to those usually obtained for seasonal vaccines. Third, each manufacturer uses the vaccine formulation that is most "dose-sparing" (i.e. using a smaller quantity of active principle). A more conservative estimate of global capacity is at least 1 to 2 billion doses per year. The numbers of persons who might be vaccinated will not be known until it is determined whether one or two doses of the vaccine will be needed to achieve protection.
What technologies will be used to grow pandemic influenza A (H1N1) viruses to make vaccines?
Most of these vaccines will be produced using chicken eggs, while a few manufacturers are using cell culture technology for vaccine production.
How is the production capacity for influenza vaccines distributed geographically?
Around 70% of the global seasonal influenza vaccine production capacity today is located in Europe and North America, with further significant manufacturing capacity in Australia, Japan and China. During the past three years, six manufacturers in developing countries have begun to acquire the technology to produce influenza vaccines and have received technical and financial support from WHO. Since May 2009, five additional new producers have joined this initiative.
Will there be enough pandemic influenza A (H1N1) vaccine for everyone?
When pandemic vaccine first becomes available, it is anticipated that the demand will be greater than the supply. This gap will narrow as more vaccine becomes available over time.
Who will receive priority for vaccination?
WHO is working with the Strategic Advisory Group of Experts (SAGE) on Immunization and partners on the options for deciding in which target groups vaccination should begin first. At its July 7 meeting, SAGE recommended that health care workers worldwide should be immunized as a first priority (see: Pandemic (H1N1) 2009 briefing note 2 below). Ultimately, national authorities will identify priority groups for vaccination based on circumstances within the country.
Will developing countries have access to pandemic influenza vaccines?
The WHO Director-General has called for international solidarity to provide fair and equitable access for all countries to pandemic vaccine when it becomes available. WHO has requested that manufacturers set aside future influenza A (H1N1) vaccines for developing country populations, through donations or affordable pricing arrangements.