What are the plans for developing 2009 H1N1 vaccine?

Vaccines are the most powerful public health tool for control of influenza, and the U.S. government is working closely with manufacturers to take steps in the process to manufacture a 2009 H1N1 vaccine. Working together with scientists in the public and private sector, CDC has isolated the new H1N1 virus and modified the virus so that it can be used to make hundreds of millions of doses of vaccine. Vaccine manufacturers are now using these materials to begin vaccine production. Making vaccine is a multi-step process which takes several months to complete. Candidate vaccines will be tested in clinical trials over the few months.

When is it expected that the 2009 H1N1 vaccine will be available?

The 2009 H1N1 vaccine is expected to be available in the fall. More specific dates cannot be provided at this time as vaccine availability depends on several factors including manufacturing time and time needed to conduct clinical trials.

Will the seasonal flu vaccine also protect against the 2009 H1N1 flu?

The seasonal flu vaccine is not expected to protect against the 2009 H1N1 flu.

Can the seasonal vaccine and the 2009 H1N1 vaccine be given at the same time?

Inactivated 2009 H1N1 vaccine can be administered at the same visit as any other vaccine, including pneumococcal polysaccharide vaccine. Live 2009 H1N1 vaccine can be administered at the same visit as any other live or inactivated vaccine EXCEPT seasonal live attenuated influenza vaccine.

Who will be recommended to receive the 2009 H1N1 vaccine?

CDC’s Advisory Committee on Immunization Practices (ACIP) has recommended that certain groups of the population receive the 2009 H1N1 vaccine when it first becomes available. These target groups include pregnant women, people who live with or care for children younger than 6 months of age, healthcare and emergency medical services personnel, persons between the ages of 6 months and 24 years old, and people ages of 25 through 64 years of age who are at higher risk for 2009 H1N1 because of chronic health disorders or compromised immune systems.

We do not expect that there will be a shortage of 2009 H1N1 vaccine, but availability and demand can be unpredictable. There is some possibility that initially the vaccine will be available in limited quantities. In this setting, the committee recommended that the following groups receive the vaccine before others: pregnant women, people who live with or care for children younger than 6 months of age, health care and emergency medical services personnel with direct patient contact, children 6 months through 4 years of age, and children 5 through 18 years of age who have chronic medical conditions.

The committee recognized the need to assess supply and demand issues at the local level. The committee further recommended that once the demand for vaccine for these target groups has been met at the local level, programs and providers should begin vaccinating everyone from ages 25 through 64 years. Current studies indicate the risk for infection among persons age 65 or older is less than the risk for younger age groups. Therefore, as vaccine supply and demand for vaccine among younger age groups is being met, programs and providers should offer vaccination to people over the age of 65.

Should I get vaccinated against 2009 H1N1 if I have had flu-like illness since the Spring of 2009?

The symptoms of influenza (flu-like illnesses) are similar to those caused by many other viruses. Even when influenza viruses are causing large numbers of people to get sick, other viruses are also causing illnesses. Specific testing, called “RT-PCR test,” is needed in order to tell if an illness is caused by a specific influenza strain or by some other virus. This test is different from rapid flu tests that doctors can do in their offices. Since most people with flu-like illnesses will not be tested with RT-PCR this season, the majority will not know whether they have been infected with 2009 H1N1 flu or a different virus.

Therefore, if you were ill but do not know if you had 2009 H1N1 infection, you should get vaccinated, if your doctor recommends it. So, most people recommended for 2009 H1N1 vaccination should be vaccinated with the 2009 H1N1 vaccine regardless of whether they had a flu-like illness earlier in the year. If you have had 2009 H1N1 flu, as confirmed by an RT-PCR test, you should have some immunity against 2009 H1N1 flu and can choose not to get the 2009 H1N1 vaccine. However, vaccination of a person with some existing immunity to the 2009 H1N1 virus will not be harmful. For more information on flu tests, see Influenza Diagnostic Testing During the 2009-2010 Flu Season.

Any immunity from 2009 H1N1 influenza infection or vaccination will not provide protection against seasonal influenza. All people who want protection from seasonal flu should still get their seasonal influenza vaccine.

Where will the vaccine be available?

Every state is developing a vaccine delivery plan. Vaccine will be available in a combination of settings such as vaccination clinics organized by local health departments, healthcare provider offices, schools, and other private settings, such as pharmacies and workplaces. For more information, see State/Jurisdiction Contact Information for Health Care Providers Interested in Providing H1N1 Vaccine.

Will this vaccine be made differently than the seasonal influenza vaccine?

No. This vaccine will be made using the same processes and facilities that are used to make the currently licensed seasonal influenza vaccines.

What about the use of antivirals to treat 2009 H1N1 infection?

CDC has issued interim guidance for the use of antiviral drugs for this season. CDC also has published Questions & Answers related to the use of antiviral drugs for this season.

Other Resources

* Find a Flu Clinic
American Lung Association's Flu Clinic Locator site.

* Your Questions Answered
2009-10 Seasonal Influenza Vaccine Updates: Questions & Answers.

* How Well Does the Seasonal Flu Vaccine Work?
Find out the myths and facts of the vaccine.

* Protect Your Children
Children, the Flu, and the Flu Vaccine.

Please visit the CDC for more information and to learn more.