Frequently Asked Questions (FAQ) on Influenza Vaccination

Topic Areas / Quick Menu

1. General Questions
2. Novel or Pandemic Influenza
3. Eligibility for Influenza Vaccination in VA
4. HIV/AIDS and Influenza Vaccination
5. Influenza Vaccine Storage
6. Live, attenuated, intranasal influenza vaccine (LAIV)

1. General questions

How is influenza illness defined?

Influenza is a febrile respiratory illness caused by influenza virus that can be prevented by vaccination. The table below differentiates influenza from a ‘cold’.

What should everyone know about the flu season?

• The first cases of influenza in the U.S. are usually identified in October.
• Widespread influenza activity appears 6-10 weeks after the first case.
• Influenza kills about 36,000 and hospitalizes more than 200,000 persons in the U.S. each year
• The influenza vaccine changes each year to match the currently circulating type of influenza.
• The 2005-06 influenza vaccine contains the following types:
  • A/California (H3N2)
  • A/New Caledonia (H1N1)
  • B/Shanghai
• One needs an influenza vaccine each year to get the latest protection.
• Influenza vaccination usually begins in September and October in the VA health care system, and continues through March or April.
• Influenza vaccine takes 1-2 weeks to generate protective immunity.

What are the recommendations for vaccination of health care workers against influenza?

All health care workers with patient contact should receive annual influenza vaccination unless they have a contraindication to the vaccine. Vaccination is recommended for health care workers for at least 3 reasons:

• health care workers can give influenza to their patients, co-workers, family members, and others;
• health care workers are at risk of getting influenza from patients with influenza; and
• preventing influenza by vaccinating keeps health care workers healthy and available to come to work to take care of patients.

How will we know whom to vaccinate when? For example, early in the 2004-2005 season, employees not involved in direct care were not supposed to be vaccinated by VA even if the individual employee was over 65 and/or had medical risks from consequences of flu. Will this be the correct approach this year?

For the 2005-2006 season, it is uncertain what the total influenza vaccine supply will be. The CDC and the VA Undersecretary for Health will issue regular advisories and updates to define the timing of priority groups for vaccination. Watch for VA Influenza Vaccine Advisories sent out broadly by email and posted on http://www.publichealth.va.gov/flu/

What else (besides vaccine) can one do to protect oneself and others from influenza illness?

• Cover your nose and mouth with a tissue when you cough or sneeze, and dispose of the tissue afterward.
• If you don't have a tissue, cough or sneeze into your sleeve.
• Clean your hands after you cough or sneeze with soap and warm water or an alcohol-based hand cleaner.
  This VA Infection: Don't Pass It On campaign website includes posters, information, and links about hand and respiratory hygiene: http://www.publichealth.va.gov/infectiondontpassiton/
• If you get the flu, avoid exposing others. Stay home from work or school until your fever is gone, and you feel ready to resume normal activities.
• Get pneumococcal vaccine if you’re age 65 or older or have a chronic health condition.

What about antiviral medications?

The antiviral medications amantadine (Symmetrel®) and rimantadine (Flumadine®) are on the VA National Formulary and approved for prevention and treatment of influenza A. An alternative for treatment is oseltamivir (Tamiflu®). A supply of oseltamivir is maintained in a VA stockpile for outbreaks of a very serious nature.

Antivirals are most often used to help contain influenza outbreaks in setting such as nursing homes or to protect a high-risk person who is in direct contact with someone who has influenza.

There are some risks in taking antivirals. Some people have serious side effects from them.

To be effective, antivirals should be taken within 24-48 hours of being exposed to influenza or onset of symptoms.

2.  Novel Pandemic or Avian Influenza

What is the difference between regular influenza that is around every year and novel pandemic or avian flu?

Influenza virus circulates in humans every year, usually in winter. Several times each century, a strain that is new to humans originates from the re-assortment of a human and animal (sometimes bird or avian) strains. These new or novel strains cause pandemics that can be very serious, because humans have little pre-existing immunity to them and vaccines and antiviral medications take time to develop, supply, and distribute. The 1918-19 pandemic caused as many as 500,000 deaths in the U.S. and 50 million globally. Public health experts around the world and within VA are concerned about and are taking steps to prepare for a pandemic of novel influenza.

3. Eligibility for Influenza Vaccination in VA 

Many wives and children of 100% service connected veterans who have CHAMPVA (Civilian Health and Medical Program of the Department of Veterans Affairs) visit VA medical facilities for flu shots. In some cases, vaccination has been provided to these groups if they meet criteria for flu vaccine. Is this the correct approach?

VA medicines, supplies, etc, cannot legally be given to non-veterans--even if giving influenza vaccine to a non-veteran caregiver of a veteran might prevent the transmission of the flu to a veteran.

Our facility has permitted veterans not currently enrolled for VA health care to go through screening for income or service-connected criteria for enrollment in order to get influenza vaccination. If they meet VA enrollment criteria, then they are given vaccine if they are within one of the priority groups for vaccine. Is this the correct procedure for veterans who might not be cared for by VA?

As long as a supply of vaccine is available, vaccine should be provided to veterans who are enrolled in VA care and who are currently in one of the priority groups as advised by the Under Secretary for Health’s Annual Influenza Directive or by a current Influenza Vaccine Advisory. These documents will be posted and kept current at http://www.publichealth.va.gov/flu/

Requests for vaccine have been received from our state Soldiers Homes and Nursing Homes that house VA patients. It is difficult to control the supply in these situations, especially in nursing homes where only a few are VA patients. Also, is VA mandated to provide vaccine for employees in Soldier’s Homes and Nursing Homes?

State Soldiers Homes’ supplies are provided via individual contracts. Unless a VA facility has an agreement to vaccinate residents in a state Soldiers Home or Nursing Home, those veterans would need to visit a VA facility for their vaccination if they are enrolled for VA health care and belong to one of a priority group for vaccination. Only appropriate (i.e. direct patient care) employees within VA facilities can be vaccinated (unless an existing agreement has been negotiated for the State Home or Nursing Home employees). Even if a place houses and cares for veterans, it is not a de facto responsibility of VA to go on site and deliver care unless there are existing agreements to provide care.

Our facility does not vaccinate direct patient care volunteers based on the assumption that they can stay at home if necessary. Is this interpretation correct?

The decision with regard to volunteers is an individual VA facility decision. Some VA medical facilities consider volunteers to be necessary for direct patient care functions and include them in the vaccination plans as they would paid employees. Individual VA facilities must evaluate their volunteers’ functions and decide on vaccine eligibility.

Should we offer vaccine to medical residents and other trainees who provide direct patient care at the VA during the flu season through our Occupational Health Department?

The decision with regard to residents and other trainees is an individual VA facility decision and should take into account the contractual agreement with the academic affiliate and the availability of the vaccine. Facilities may want to make the same decisions about providing flu vaccine for rotating or temporary trainees (e.g. house staff/medical residents) as they would for volunteers: if they provide needed, direct, hands-on patient care and the VA facility has vaccine available, these individuals should be vaccinated.

Are homeless veterans who attend stand-downs eligible for influenza vaccine?

Flu vaccine given by VA is for veterans who are enrolled for VA health care and who meet existing priority group and tiered vaccination timing plans (if any). If there is any question about a homeless veteran falling within a priority group, VA staff should use their best medical judgment. A very large percentage of homeless veterans are likely to have qualifying medical conditions that meet CDC criteria.

4. HIV/AIDS and Influenza Vaccination

Should people with HIV/AIDS receive influenza vaccine?

People with chronic underlying medical conditions, including HIV/AIDS, should be vaccinated with inactivated influenza vaccine. People with HIV/AIDS are considered at increased risk from serious influenza-related complications. Persons with advanced HIV disease may have a poor response to immunization. Therefore, chemoprophylaxis (use of antiviral medications for prevention) should also be considered for these patients if they are likely to be exposed to people with influenza. 

Are there people with HIV/AIDS who should NOT receive flu shots?

Contraindications to the use of the flu shot in persons with HIV/AIDS are the same as those for uninfected persons: a history of severe allergy (i.e., anaphylactic allergic reaction) to hens' eggs, or a history of onset of Guillain-Barre syndrome during the 6 weeks after vaccination.

Can people with HIV/AIDS receive the live attenuated flu vaccine (LAIV, sold commercially as FluMist™)?

No. Persons with HIV/AIDS are not recommended to receive the live influenza vaccine. LAIV is approved for use only among healthy persons between the ages of 5 and 49 years.

When should people with HIV/AIDS be prescribed antiviral medications for chemoprophylaxis (prevention)?

Persons at high risk of serious influenza-related complications should be given antiviral medications if they are likely to have been exposed to other people with influenza. For example, when a family or household member is diagnosed with influenza, the exposed person with HIV/AIDS should be given chemoprophylaxis for 7 days. Vaccinated and unvaccinated HIV-infected persons who are residents of institutions experiencing an influenza outbreak should be given chemoprophylaxis for the duration of the outbreak or until discharge. People with advanced HIV disease who are not expected to mount an adequate antibody response to influenza vaccination should consider chemoprophylaxis with antiviral medications for the duration of influenza activity in the community, if antiviral medications are available in adequate supply.

There are no published data on interactions between anti-influenza agents such as amantidine and rimantidine and drugs used in the management of HIV infected persons. Patients should be observed for adverse drug reactions to anti-influenza chemoprophylaxis agents, especially when neurologic conditions or renal insufficiency are present.

Should health care workers who have contact with HIV/AIDS patients be vaccinated?

All health care workers with patient contact should receive annual influenza vaccination unless they have a contraindication to the vaccine. Vaccination is recommended for health care workers for at least 3 reasons:

• health care workers can give influenza to their patients, co-workers, family members, and others
• health care workers are at risk of getting influenza from patients with influenza;
• preventing influenza by vaccinating keeps health care workers healthy and available to come to work to take care of patients

5. Influenza Vaccine Storage

CDC recommends that influenza vaccine be refrigerated during shipment and immediately upon being received and to prevent from freezing. Would pre-filling syringes and leaving them out of the refrigerator for use during high volume vaccination efforts affect the potency of the vaccine?   

A contact at CDC knew of no data on vaccine stability once the vaccine is in the syringe, but the following cautions make sense:

• Don’t prefill a large number of syringes because of:
  • Increased risk for administration errors
  • Chance of wasting vaccine
  • Risk of inappropriate storage conditions
  • Potential for bacterial overgrowth in vaccines that do not contain a preservative
  • Reduced vaccine potency
• Prefill only a few syringes at a time
  • Prefill the smallest logical number according to your patient flow
  • Try to fill no more than 10 prefilled syringes at a time (1 vial) per person vaccinating
  • Discard any prefilled syringes remaining at the end of the clinic session.
  • Mark the container of prefilled syringes with the date and time of filling
  • Mark each syringe with the date, time and medication.
• In setting up a mass vaccination clinic:
  • Administer only one type of vaccine per station (keep influenza and pneumococcal vaccines separate)
  • Transport the vaccine to the clinic in the manufacturer-supplied packaging at the recommended temperatures
  • Keep vaccine vials and prefilled syringes in a cooler (but not in direct contact with ice)

6. Live, Attenuated, Intranasal Influenza Vaccine (LAIV or Flumist™)

LAIV is so new. Is it a safe vaccine?

The development of the live attenuated influenza vaccine has been going on since the 1960s. Prior to licensure, the safety of LAIV was studied in 20 clinical trials. More than 6,000 clinical trial participants were in the approved age range of 5-49 years. In healthy children there were no significant differences between vaccine and placebo recipients. Serious adverse reactions have been identified in less than 1% of LAIV recipients, either children or adults, since licensure.

There have been no instances of Guillain-Barré Syndrome reported among LAIV recipients.

Is LAIV really an option for health care workers?

Yes, LAIV is an option for healthy health care workers up through age 49, especially when there is a shortage of inactivated influenza vaccine. Choosing LAIV, currently available as FluMist™, means you are helping to conserve when there is limited inactivated influenza vaccine for high-risk persons who do not have the option of live attenuated influenza vaccine.

Is FluMist™ the only live attenuated influenza vaccine available in the United States?

Yes. FluMist™ is the only live attenuated influenza vaccine licensed for use in the United States. FluMist™ was approved by the FDA in June 2003 and is given intranasally (in the nose).

What does “attenuated” mean?

Attenuated means that the influenza viruses used to make LAIV have been weakened so they cannot grow well in human tissue. Six parts of the genetic material used to make the vaccine have been modified. In order for the vaccine to become as strong as the wild influenza virus, all six of these components would have to undergo genetic changes. Throughout clinical trials, the stability of the virus was studied and it was found that all six of the genetic components of LAIV remained stable maintaining its attenuated, cold-adapted characteristics.

I read that LAIV is “cold adapted.” What does that mean?

Cold adapted means the vaccine survives and replicates only at temperatures less than 25° Celsius. This temperature range allows the vaccine to grow well in the nose and throat. However, once the virus reaches the lower respiratory tract, the warm temperature destroys the virus. This means the vaccine virus, unlike influenza virus, cannot replicate and cause disease.

Is shedding the virus a problem for health care workers?

The FluMist™ package insert states that a person can shed the virus for up to three weeks because that is what the studies in humans showed, but shedding alone should not be equated with person-to-person transmission. In fact, studies have found that it is very rare. In a study conducted in a Finnish daycare center that was designed to maximize the chance of detecting vaccine virus transmission, one child shed the virus for 21 days. Other children in this study shed the virus a mean of 7.6 days. Estimated transmission rates were extremely low (0.6%-2.4%). There was actually only one documented case of LAIV transmission. An additional small study of 40 adults conducted since licensure found that only 50% of the adults were shedding the vaccine influenza virus on day three after vaccination, one adult shed the virus on day seven. That means that half the adults had stopped shedding the virus by day three. These post licensure studies prompted the Advisory Committee on Immunization Practices (ACIP, an independent committee that advises CDC) to reduce the recommended number of days a HCW should avoid contact with patients requiring protective isolation - from three weeks to seven days.

What if the shed virus is transmitted? Isn't that dangerous?

The virus is shed in lower titers than typically occur with shedding of wild-type influenza viruses. So even if transmission were to occur, there are not enough viral particles to make a person ill. The virus also retains its attenuated characteristics, thus cannot replicate in the lower respiratory tract. The bottom line? Shedding and rare subsequent transmission cannot be presumed to cause disease.

Is LAIV as effective as the regular influenza vaccine?

Yes. Studies conducted before the licensure of LAIV show that it is very protective against influenza disease. CDC discusses the efficacy as follows: “In one large study among children aged 15-85 months, the nasal-spray flu vaccine (LAIV) reduced the chance of influenza illness by 92% compared with placebo. In a study among adults, the participants were not specifically tested for influenza. However, the study found 19% fewer severe febrile respiratory tract illnesses, 24% fewer respiratory tract illnesses with fever, 23-27% fewer days of illness, 13-28% fewer lost work days, 15-41% fewer health care provider visits, and 43-47% less use of antibiotics compared with placebo.” Efficacy of inactivated influenza vaccine is about 70-90% in adults <65 years, and 77-91% effective in children 1-15 years of age. Thus, LAIV is at least as effective as inactivated vaccine.

Who can get LAIV?

People 5 through 49 years of age without any chronic health conditions are eligible for LAIV. This includes household contacts and out-of-home caregivers of infants less than 6 months of age, health care workers, and contacts of persons who have chronic health conditions.

Who cannot get LAIV?

Because no studies were completed at licensure to determine the efficacy or safety in certain persons, LAIV is not recommended for the following:

• People with medical conditions that place them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airways disease; people with medical conditions such as diabetes or kidney failure; or people with illnesses that weaken the immune system or who take medications that can weaken the immune system.
• Children or adolescents receiving aspirin therapy.
• People with a history of Guillain-Barré Syndrome, a rare disorder of the nervous system.
• Pregnant women.
• People with a history of allergy to any of the components of LAIV or to eggs.

Can contacts of the persons listed above be vaccinated with LAIV?

Yes. There is only one instance in which healthy people should consider the inactivated flu injection over LAIV – when they are caring for persons requiring protective isolation, e.g., post bone marrow transplant.

Can contacts of persons with weakened immune systems be vaccinated with LAIV?

Yes, LAIV can be used in contacts of persons who have HIV/AIDS, who are on chemotherapy, or who have diseases that weaken their immune system. Remember that the vaccine uses a weakened virus that doesn’t contain a viral dose big enough to cause disease. Also, once the virus gets to the lower respiratory tract the warmer temperatures kill it.

Should health care workers who have a contraindication to LAIV administer it?

Environmental contamination with LAIV during administration is probably unavoidable. However, because it is an attenuated virus (weakened), that is designed not to replicate at the warm temperatures of the lower respiratory tract, the ACIP does not believe that administration of LAIV by a person with one of the contraindications to it (like asthma, chronic obstructive pulmonary disease, etc) is at risk from infection or illness from the vaccine virus.

What side effects are associated with LAIV?

In children, the most common side effects can include runny nose, headache, vomiting, muscle aches, and fever. In clinical trials upper respiratory symptoms, such as runny nose and nasal congestion, fever, or other systemic symptoms, were reported in 10%-40% of both vaccine and placebo recipients. Adults may experience a runny nose, headache, sore throat, and cough. Unlike children, fever is not a common side effect in adults receiving LAIV.

Can LAIV be given to patients when they are ill?

Persons with mild illnesses, e.g., diarrhea or mild upper respiratory tract infection, with or without fever, may receive the nasal spray flu vaccine (LAIV). Vaccination may need to be delayed for persons who have an illness that has caused nasal congestion because of the interference of vaccine delivery.

Some general questions and questions on LAIV in these FAQs were adapted from the Minnesota Department of Health’s website on influenza, available at http://www.health.state.mn.us/divs/idepc/diseases/flu/*.

Used with permission.

* External Link Disclaimer:
All the links marked with asterisk ( * ) are External links. By clicking on these links, you will leave the Department of Veterans Affairs Website. VA does not endorse and is not responsible for the content of the linked website. Links will open in a new browser window.

Public Health Strategic Healthcare Group | Office of Public Health and Environmental Hazards