Q&A about Flu with David Neumann, PhD, Executive Director of the National Partnership on Immunization

David A. Neumann, PhD, is the Executive Director of the National Partnership for Immunization (NPI), a non-profit organization founded in 2000 to increase awareness, acceptance and use of licensed vaccines by people of all ages throughout the US. His organization created National Immunization Awareness Month, which is observed each August, to remind the public as well as health care providers that vaccines protect individuals, families and communities from the debilitating and potentially deadly consequences of vaccine-preventable diseases. David has led NPI’s efforts to build partnerships within the public health community to provide the public, the media and health care professionals with educational tools and resources about the importance and value of timely immunization. HMHB recently spoke with David about the “flu.”

Q. Why do we hear so much about the flu each fall? It’s really that serious, is it?

A. Influenza or flu is extremely serious, and all too often deadly. Influenza disease is caused by two types of viruses that typically circulate through the US each fall and winter. The disease’s symptoms include fever, headache, sore throat, cough, muscle ache and tiredness. In children, it also may cause nausea and vomiting. The symptoms may persist for two weeks or more and it can aggravate underlying disease such as asthma or diabetes and lead to the development of pneumonia or other infections. These symptoms result in lost time from school and work and disrupt people’s day-to-day activities. Although people tend to characterize each influenza season as mild or serious, every season is really serious. On average each year, over 200,000 people are hospitalized and 36,000 die because of flu and its complications. Those who make light of the flu really don’t appreciate the seriousness of the disease nor its potentially deadly consequences.

Q. Last year there were many reports about children being hospitalized and even dying because of the flu, is this unusual? Isn’t influenza more of an issue for the elderly?

A. For many years, public health concerns about influenza were largely focused on the elderly, those 65 years of age and older. This was because people in that age group who contracted flu often had a more severe case of the disease or developed complications, like pneumonia, which resulted in high rates of hospitalization and large numbers of deaths each year. Preliminary data for 2002 from the Centers for Disease Control and Prevention (CDC) indicate that influenza and pneumonia are the 5th leading cause of death among people 65 and older.

The 2003-2004 flu season was unusual because it arrived early (October) and was accompanied by well-publicized reports of serious cases of disease among children resulting in hospitalization and death. The CDC has since confirmed that there were 152 influenza related deaths among children last flu season. We don’t know whether this represents an unusually large number of pediatric deaths or is typical of most flu seasons. Because of this uncertainty, the CDC now requires that all influenza-related deaths among children be reported to the agency.

Q. What are public health officials going to do about protecting children from the flu?

A. Actually, the public health community has been concerned about influenza and children for some time because a number of published studies have shown that flu-related hospitalizations of young children are similar to the rates seen among the elderly. This led the CDC to recommend that all children between the ages of six (6) and 23 months be given the influenza vaccine. This recommendation applies to the current (2004-2005) flu season and was actually put into practice during the 2003-2004 season as the spread and impact of the disease became apparent.

Q. Can you describe the vaccine?

A. The disease can be caused by several different types of influenza virus; most is attributable to types A and B. Type A is associated with more severe disease and has a variety of subtypes that can change through various natural processes, referred to as antigenic drift. Type B virus also drift, but less rapidly than the A viruses.

The vaccine that protects against influenza is targeted to the portions of the A and B viruses that are most prone to antigenic drift. Because type A can drift so quickly, we often need to produce a somewhat different vaccine each year in order to protect against disease. This poses a considerable challenge to the public health community because in order to have enough vaccine to go around during the fall and winter flu season, decisions about the composition of the vaccine must be made early in the calendar year. Health officials are usually able to accurately predict the relevant subtypes to include in the vaccine. Occasionally, like last year, the virus in the vaccine and the virus that is responsible for most flu season illness are not well-matched. Even so, the vaccine can reduce the severity of the disease, lost time from work or school, the risk of hospitalization and the risk of influenza-related death.

We now have two types of influenza vaccine. One, the familiar injectable vaccine is made from two Type A viruses and one Type B virus. The viruses in this vaccine are inactivated and cannot cause influenza in vaccine recipients. A new influenza vaccine was introduced last year that is administered as a nasal spray. It also contains two Type A viruses and one Type B virus. The viruses in this vaccine are live, but have been attenuated, that is, altered to produce a protective response when given without causing serious disease. The intranasal vaccine is recommended only for healthy people ages five (5) to 49; the injectable vaccine is appropriate everyone for whom the vaccine is recommended.

Q. How does the vaccine work?

A. When we are naturally exposed to influenza viruses in the absence of immunization, they localize in the lungs and elicit the variety of familiar flu symptoms. Our immune systems respond to the virus invasion by producing antibodies and other agents that seek out and destroy the viruses. Some of the symptoms that we experience result from our response to the infection. The end result is that we develop immunity to the virus, but at the expense of experiencing the disease. If we later encounter the same type of virus, we will be protected against the associated disease. The vaccines are designed to trigger a much more modest set of responses that result in a similar level of immune protection that will protect us against disease, even on a first time exposure to the viruses.

Q. Why does flu spread so quickly through communities?

A. The disease causing viruses are easily spread from person to person by coughing and sneezing. Covering your mouth when coughing and using tissues can help block the spread of the viruses. Frequent hand washing is also important in limiting disease transmission.

Vaccines play an important role in limiting the spread of the disease. By being immunized, an individual is less likely to acquire the disease from others or to be a source of infection. The term community immunity refers to the idea that, as more people in a community are immunized, the risk that others in the community will become infected is reduced. Current influenza immunization recommendations call attention to the importance of parents, siblings and child care givers being immunized in order to reduce the likelihood of exposing children six (6) to 23 months of age to disease-causing viruses. Likewise, those caring for or in households with the elderly, people with diabetes or asthma or chronic diseases of the heart, lungs or liver, all of whom are at high risk for influenza or its complications, should be immunized annually against influenza.

Q. Who else should be immunized against influenza?

A. Actually, the vaccine is recommended for nearly two thirds of the US population. In addition to the groups that we’ve already discussed, it’s recommended for all adults between 50 and 64 years of age, women who will be pregnant during flu season, residents of nursing homes and chronic care facilities regardless of age, those whose immune systems are suppressed due to medications or human immunodeficiency virus infections and people six (6) months to 18 years of age who receive chronic aspirin therapy. It is worth repeating that the intranasal vaccine is recommended only for healthy people five (5) to 49 years of age; it is not recommended for people in any of the risk groups that I’ve mentioned.

Q. Are there people who should not receive the vaccine?

A. Influenza vaccine is not recommended for people known to have acute hypersensitivities to eggs or other components of the vaccine. It also should not be given to people with acute febrile illness until their symptoms have abated.

Q. Are there side effects of or adverse reactions to the vaccine?

A. For the injectable vaccine, adults often note soreness at the injection site that may persist for one or two days; swelling has also been reported. Similar reactions are seen in children. Reactions such as fever, tiredness, headache and muscle ache have been observed, particularly in those with no previous exposure to the virus in the vaccine. For the nasal spray vaccine, possible side effects for both and children include headache and runny nose or nasal congestion. Children may experience fever, vomiting and muscle ache, while adults may experience cough, sore throat or tiredness.

Q. When should people be immunized against influenza?

A. Typically, the manufacturers begin shipping vaccines to health care providers and public health facilities during September, with immunizations beginning around the first of October. Generally, the vaccine is first given to people 50 and older, those under 50 who are at increased risk for influenza-related complications, their household contacts and health care workers. Children under the age of nine (9) should also be given the vaccine during October because they actually need two doses, one month apart. All other people should be given the vaccine during November, and the vaccine can be administered in December or later. In the US, peak influenza activity typically can occur between late December and early March.

Q. Any final thoughts, David?

A. Influenza is a serious, life-threatening disease that affects people of all ages. We have vaccines that can reduce the burden of disease caused by the flu each year, yet these vaccines are underutilized. Although approximately 180 million people in the US qualify to receive the vaccine under the current recommendations, vaccine use is disappointingly low. Each year over the past five or six years, roughly 80 to 85 million doses of the vaccine have been produced. Except for last year when virtually every available dose was used, we usually find that 10 to 15 million doses go unused. We need to do much better than that. If we’re serious about disease prevention and about being prepared for disease outbreaks, then we need to get serious about influenza immunization.

For more information about NPI and immunizations, contact them at 703-837-4792.