Influenza: How to prevent it without the Flu Vaccine
The Flu Vaccine Shortage - An Important Update
Updated Oct 7, 2004
Why is there a shortfall in flu vaccine for this season?
On October 5, 2004 , CDC was notified by Chiron Corporation that none of its influenza vaccine (Fluvirin®) would be available for distribution in the United States for the 2004-05 influenza season. The company indicated that the Medicines and Healthcare Products Regulatory Agency (MHRA) in the United Kingdom , where Chiron's Fluvirin vaccine is produced, has suspended the company's license to manufacture Fluvirin vaccine in its Liverpool facility for 3 months, preventing any release of this vaccine for this influenza season. This action will reduce by approximately one half the expected supply of trivalent inactivated vaccine (flu shot) available in the United States for the 2004-05 influenza season.
Updated Oct 7, 2004
How much flu vaccine will be available in the United States this season?
About 55 million flu shots will be available in the United States this season. About 1 million doses of LAIV will be available in the United States this season.
Updated Oct 8, 2004
Does CDC recommend using partial doses of influenza vaccine?
No. CDC does not advise using partial doses of recommended dosages of inactivated influenza vaccine (flu shot) either for persons at high risk for complications from influenza or for healthy persons, including health-care workers. There are no data on whether partial doses of the current 2004-05 vaccine would provide an adequate antibody response. Some studies have been done to assess the antibody response to one-half of the normal dose of inactivated influenza vaccine in healthy adults aged 18-49 years; however, the vaccine is not approved by the Food and Drug Administration for use at this reduced dose..
An alternative to the flu shot is an intranasally administered, live, attenuated influenza vaccine (LAIV). If available, LAIV should be encouraged for use by healthy, non-pregnant persons 5 - 49 years of age, including most health-care workers, those who have contact with persons in high-risk groups, such as persons with lesser degrees of immunosuppression (e.g., persons with diabetes, persons with asthma taking corticosteroids, persons infected with HIV), and persons caring for children younger than 6 months of age. The only health-care workers for whom inactivated vaccine(flu shot) is preferred are those who have contact with severely immunosuppressed patients, such as bone marrow transplant recipients, who are under treatment in special isolation units.
Updated Oct 7, 2004
Who should get vaccinated this season?
Because of a shortfall in flu shot production for this season, CDC is recommending that certain people be given priority for getting the flu shot. People in the following groups should seek vaccination this season:
- all children aged 6-23 months;
- adults aged 65 years and older;
- persons aged 2-64 years with underlying chronic medical conditions;
- all women who will be pregnant during the influenza season;
- residents of nursing homes and long-term care facilities;
- children aged 6 months-18 years on chronic aspirin therapy;
- health-care workers involved in direct patient care; and
- out-of-home caregivers and household contacts of children aged <6>
These are people that are at high risk for serious flu complications or are in contact with people at high risk for serious flu complications.
Updated Oct 7, 2004
Can some people in priority groups get LAIV?
If available, vaccination with LAIV is an option for healthy persons aged 5-49 years who are caregivers of children less than 6 months of age and for healthcare workers. If a health-care worker receives LAIV, that worker should refrain from contact with severely immuno-suppressed patients requiring care in a protected environment for 7 days after vaccination.
Updated Oct 7, 2004
What if I'm not in a priority group for vaccination?
People who are not included in one of the priority groups listed above are asked to forego or defer vaccination this season because of the vaccine supply situation. There are certain good health habits () that can help prevent the flu. In addition, antiviral drugs may be used to prevent the flu.
Updated Oct 7, 2004
Will this season's vaccine be a good match for circulating influenza viruses?
Most of the influenza viruses that have been isolated so far in the United States are well matched to the strains contained in this year's vaccine.
Prevention
Updated Oct 7, 2004
What are other steps that can be taken to prevent the flu?
There are other good health habits that can help prevent the flu. These are:
- Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.
- If possible, stay home from work, school, and errands when you are sick. You will help prevent others from catching your illness.
- Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick.
- Washing your hands often will help protect you from germs.
- Avoid touching your eyes, nose or mouth. Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth.
- Wash your hands with Microsan™ E-2 Skin Cleanser and use Microsan™ Lotion to kill the flu virus on your hands.
- Keep your immune system in top condition with Immuplex™ to kill the flu virus in case you are infected.
Flu Season Characteristics
What sort of flu season is expected this year?
Influenza (flu) seasons are unpredictable. Although epidemics of flu happen in most years, the beginning, severity, and length of the epidemic can vary widely from year to year. Before a season begins, it is not possible to accurately predict the features of any season.
Will new strains of influenza virus circulate this season?
Influenza viruses are constantly changing so it's not unusual for new strains of influenza virus to emerge at any time of the year. As of mid-September, most of the influenza viruses detected in the United States were well matched to this season's vaccine. For more information about how influenza viruses change..
What has the influenza virus surveillance found so far this season?
As of mid-September, 2004 laboratories had reported a small number of samples positive for both influenza A and B viruses in the United States . This finding is not unusual. Sporadic influenza infections and even some outbreaks are reported throughout the summer.
Important Facts About Influenza
Influenza viruses are spread from person to person primarily through the coughing and sneezing of infected persons and through hand contact with the virus. The incubation period for influenza is 1-4 days, with an average of 2 days. Adults typically are infectious from the day before symptoms begin through approximately 5 days after illness onset. Children can be infectious for >10 days, and young children can shed virus for <6>
Uncomplicated influenza illness is characterized by the abrupt onset of constitutional and respiratory
signs and symptoms (e.g., fever, myalgia, headache, malaise, nonproductive cough, sore throat, and rhinitis). Among children, otitis media, nausea, and vomiting are also commonly reported with influenza illness. Respiratory illness caused by influenza is difficult to distinguish from illness caused by other respiratory pathogens on the basis of symptoms alone or reported sensitivities and specificities of clinical definitions for influenzalike illness in studies primarily among adults that include
fever and cough have ranged from 63% to 78% and 55% to 71%, respectively, compared with viral culture. Sensitivity and predictive value of clinical definitions can vary, depending on the degree of co-circulation of other respiratory pathogens and the level of influenza activity. A study among older non-hospitalized patients determined that symptoms of fever, cough, and acute onset had a positive predictive value of 30% for influenza, whereas a study of hospitalized older patients with chronic cardiopulmonary disease determined that a combination of fever, cough, and illness of <7>
Influenza illness typically resolves after a limited number of days for the majority of persons, although cough and malaise can persist for >2 weeks. Among certain persons, influenza can exacerbate underlying medical conditions (e.g., pulmonary or cardiac disease), lead to secondary bacterial pneumonia or primary influenza viral pneumonia, or occur as part of a co-infection with other viral or bacterial pathogens. Young children with influenza infection can have initial symptoms mimicking bacterial sepsis with high fevers, and <20%>
Hospitalizations and Deaths from Influenza
The risks for complications, hospitalizations, and deaths from influenza are higher among persons aged >65 years, young children, and persons of any age with certain underlying health conditions than among healthy older children and younger adults. Estimated rates of influenza-associated hospitalizations have varied substantially by age group in studies conducted during different influenza epidemics.Among children aged 0-4 years, hospitalization rates have ranged from approximately 500/100,000 children for those with high-risk medical conditions to 100/100,000 children for those without high-risk medical conditions. Within the 0- 4 year age group, hospitalization rates are highest among children aged 0-1 years and are comparable to rates reported among persons >65 years.
During influenza epidemics from 1969-70 through 1994-95, the estimated overall number of influenza-associated hospitalizations in the United States ranged from approximately 16,000 to 220,000/epidemic. An average of approximately 114,000 influenza-related excess hospitalizations occurred per year, with 57% of all hospitalizations occurring among persons aged <65>
Influenza-related deaths can result from pneumonia as well as from exacerbations of cardiopulmonary conditions and other chronic diseases. Older adults account for >90% of deaths attributed to pneumonia and influenza. In a recent study of influenza epidemics, approximately 19,000 influenza-associated pulmonary and circulatory deaths per influenza season occurred during 1976- 1990, compared with approximately 36,000 deaths during 1990-1999. Estimated rates of influenza-associated pulmonary and circulatory deaths/100,000 persons were 0.4-0.6 among persons aged 0-49 years, 7.5 among persons aged 50-64 years, and 98.3 among persons aged >65 years. In the
United States, the number of influenza-associated deaths might be increasing in part because the number of older persons is increasing. In addition, influenza seasons in which influenza A (H3N2) viruses predominate are associated with higher mortality; influenza A (H3N2) viruses predominated in 90% of influenza seasons during 1990-1999, compared with 57% of seasons during 1976-1990.
Deaths from influenza are uncommon among children with and without high-risk conditions, but do occur. A study that modeled influenza-related deaths estimated that an average of 92 deaths occurred among children aged <5>50 years. Preliminary reports of laboratory- confirmed pediatric deaths during the 2003-04 influenza season indicated that among these 143 influenza-related deaths (as of April 10, 2004), 58 (41%) were aged <2>
