Influenza Vaccination Information for Health Care Workers

Did You Know?

  • CDC, the Advisory Committee on Immunization Practices (ACIP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) recommend that all U.S. health care workers get vaccinated annually against influenza.
  • Health care workers include (but are not limited to) physicians, nurses, nursing assistants, therapists, technicians, emergency medical service personnel, dental personnel, pharmacists, laboratory personnel, autopsy personnel, students and trainees, contractual staff not employed by the health-care facility, and persons (e.g., clerical, dietary, housekeeping, laundry, security, maintenance, administrative, billing, and volunteers) not directly involved in patient care but potentially exposed to infectious agents that can be transmitted to and from health care workers and patients.

Why Get Vaccinated?

  • Influenza (flu) can be a serious disease that can lead to hospitalization and sometimes even death. Anyone can get very sick from flu, including people who are otherwise healthy.
  • You can get flu from patients and coworkers who are sick with flu.
  • If you get the flu, you can spread it to others even if you don’t feel sick.
  • By getting vaccinated, you help protect yourself, your family, and your patients.

How Many Health Care Workers Got Vaccinated Last Season?

  • 2017–18 flu vaccination coverage among health care personnel (HCP) was 78.4%, similar to coverage during the 2016–17 season (78.6%).
    • By occupation, flu vaccination coverage was highest among physicians (96.1%), pharmacists (92.2%), nurses (90.5%), and nurse practitioners and physician assistants (87.8%)
    • Flu vaccination coverage was lowest among other clinical health care personnel (80.9%), assistants and aides (71.1%), and nonclinical health care personnel (72.8%).
  • By work setting, flu vaccination coverage was highest among HCP working in hospitals (91.9%).
    • Flu vaccination coverage continues to be lower among HCP working in long-term care (LTC) settings (67.4%) compared with those working in hospitals and ambulatory settings (75.1%).
    • Vaccination coverage was highest (94.8%) among health care personnel working in settings where vaccination was required. Among health care personnel whose employers did not have a requirement for vaccination coverage was higher among those who worked in locations where vaccination was offered at the worksite at no cost for 1 day only (70.4%) or >1 day (76.0%) or who worked in locations where their employer did not provide influenza vaccination on-site at no cost but actively promoted vaccination through other mechanisms (75.1%) compared with that among health care personnel working in locations where employers did not have any vaccination-related requirements or provisions (47.6%).
  • Among unvaccinated health care personnel surveyed early in the 2017-18 flu season who did not intend to get a flu vaccination during the flu season, the most common reason reported for not getting vaccinated was fear of experiencing side effects or getting sick from the vaccine (22.1%).
  • Visit Influenza Vaccination Coverage Among Health Care Personnel — United States, 2017–18 Influenza Season for more information.
  • Visit A Toolkit for Long-term Care Employers: Increasing Influenza Vaccination among Healthcare Personnel in Long-term Care Settings.

Influenza (Flu) Facts

  • People with flu can spread it to others. Influenza viruses are spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are up to about 6 feet away or possibly be inhaled into the lungs. Less often, a person might get flu by touching a surface or object that has flu virus on it and then touching their own mouth or nose.
  • Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Children may pass the virus for longer. Symptoms start 1 to 4 days after the virus enters the body. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Some persons can be infected with the flu virus but have no symptoms. During this time, those persons may still spread the virus to others.
  • Some people, such as people 65 years and older, children younger than 5 years, pregnant women, and people with certain chronic health conditions like asthma, diabetes, or heart and lung disease, are at high risk of serious complications from flu.
  • Since health care workers may care for or live with people at high risk for influenza-related complications, it is especially important for them to get vaccinated annually.
  • Annual vaccination is important because influenza is unpredictable, flu viruses are constantly changing and immunity from vaccination declines over time.
  • CDC recommends an annual flu vaccine as the first and best way to protect against influenza. This recommendation is the same even during years when the vaccine composition (the viruses the vaccine protects against) remains unchanged from the previous season.

Flu Vaccine Facts

  • The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. Trivalent vaccines are made to protect against three flu viruses; an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. Quadrivalent vaccines protect against four viruses; the same viruses as the trivalent vaccine as well as an additional B virus.
  • Flu vaccines CANNOT cause flu. Flu vaccines are made with either killed or weakened viruses.
  • Flu vaccines are safe. Serious problems from a flu vaccine are very rare. The most common side effect that a person is likely to experience is soreness where the injection was given. This is generally mild and usually goes away after a day or two. Visit Influenza Vaccine Safety for more information.

Why Get Vaccinated?

  • Influenza (flu) can be a serious disease that can lead to hospitalization and sometimes even death. Anyone can get very sick from flu, including people who are otherwise healthy.
  • You can get flu from patients and coworkers who are sick with flu.
  • If you get the flu, you can spread it to others even if you don’t feel sick.
  • By getting vaccinated, you help protect yourself, your family, and your patients.

How Many Health Care Workers Got Vaccinated Last Season?

  • 2017–18 flu vaccination coverage among health care personnel (HCP) was 78.4%, similar to coverage during the 2016–17 season (78.6%).
    • By occupation, flu vaccination coverage was highest among physicians (96.1%), pharmacists (92.2%), nurses (90.5%), and nurse practitioners and physician assistants (87.8%)
    • Flu vaccination coverage was lowest among other clinical health care personnel (80.9%), assistants and aides (71.1%), and nonclinical health care personnel (72.8%).
  • By work setting, flu vaccination coverage was highest among HCP working in hospitals (91.9%).
    • Flu vaccination coverage continues to be lower among HCP working in long-term care (LTC) settings (67.4%) compared with those working in hospitals and ambulatory settings (75.1%).
    • Vaccination coverage was highest (94.8%) among health care personnel working in settings where vaccination was required. Among health care personnel whose employers did not have a requirement for vaccination coverage was higher among those who worked in locations where vaccination was offered at the worksite at no cost for 1 day only (70.4%) or >1 day (76.0%) or who worked in locations where their employer did not provide influenza vaccination on-site at no cost but actively promoted vaccination through other mechanisms (75.1%) compared with that among health care personnel working in locations where employers did not have any vaccination-related requirements or provisions (47.6%).
  • Among unvaccinated health care personnel surveyed early in the 2017-18 flu season who did not intend to get a flu vaccination during the flu season, the most common reason reported for not getting vaccinated was fear of experiencing side effects or getting sick from the vaccine (22.1%).
  • Visit Influenza Vaccination Coverage Among Health Care Personnel — United States, 2017–18 Influenza Season for more information.
  • Visit A Toolkit for Long-term Care Employers: Increasing Influenza Vaccination among Healthcare Personnel in Long-term Care Settings.

Influenza (Flu) Facts

  • People with flu can spread it to others. Influenza viruses are spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are up to about 6 feet away or possibly be inhaled into the lungs. Less often, a person might get flu by touching a surface or object that has flu virus on it and then touching their own mouth or nose.
  • Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Children may pass the virus for longer. Symptoms start 1 to 4 days after the virus enters the body. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Some persons can be infected with the flu virus but have no symptoms. During this time, those persons may still spread the virus to others.
  • Some people, such as people 65 years and older, children younger than 5 years, pregnant women, and people with certain chronic health conditions like asthma, diabetes, or heart and lung disease, are at high risk of serious complications from flu.
  • Since health care workers may care for or live with people at high risk for influenza-related complications, it is especially important for them to get vaccinated annually.
  • Annual vaccination is important because influenza is unpredictable, flu viruses are constantly changing and immunity from vaccination declines over time.
  • CDC recommends an annual flu vaccine as the first and best way to protect against influenza. This recommendation is the same even during years when the vaccine composition (the viruses the vaccine protects against) remains unchanged from the previous season.

Flu Vaccine Facts

  • The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. Trivalent vaccines are made to protect against three flu viruses; an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. Quadrivalent vaccines protect against four viruses; the same viruses as the trivalent vaccine as well as an additional B virus.
  • Flu vaccines CANNOT cause flu. Flu vaccines are made with either killed or weakened viruses.
  • Flu vaccines are safe. Serious problems from a flu vaccine are very rare. The most common side effect that a person is likely to experience is soreness where the injection was given. This is generally mild and usually goes away after a day or two. Visit Influenza Vaccine Safety for more information.
Who Is Recommended for Vaccination?

Everyone 6 months of age and older should get an influenza (flu) vaccine every season with rare exception. CDC’s Advisory Committee on Immunization Practices has made this recommendation since the 2010-11 influenza season.

Vaccination to prevent flu is particularly important for people who are at high risk of developing serious flu complications. See People at High Risk of Developing Flu-Related Complications for a full list of age and health factors that confer increased risk.

More information is available at Who Should Get Vaccinated Against Influenza.

Who Shouldn’t Be Vaccinated?

Different influenza (flu) vaccines are approved for use in different age groups. In addition, some vaccines are not recommended for certain groups of people. Factors that can determine a person’s suitability for vaccination, or vaccination with a particular vaccine, include a person’s age, health (current and past) and any allergies to flu vaccine or its components.

What Kinds of Seasonal Flu Vaccines Are Available?

CDC recommends use of any licensed, age-appropriate influenza (flu) vaccine during the 2019-2020 influenza season. Options include inactivated influenza vaccine [IIV], recombinant influenza vaccine [RIV], or live attenuated influenza vaccine (LAIV). Different vaccines are licensed for different age groups, and some vaccines are not recommended for some groups of people. But where more than one suitable vaccine is available, no preference is expressed for any influenza flu vaccine over another.

Both trivalent (three-component) and quadrivalent (four-component) flu vaccines will be available for 2019-2020. Most vaccines will be quadrivalent.

Trivalent flu vaccines include:

  • A high-dose trivalent flu shot, approved for people 65 years and older, which contains a higher dose of antigen (the part of the virus the immune system develops antibodies against), to help create a stronger immune response.
  • A trivalent flu shot made with adjuvant, (an ingredient that helps create a stronger immune response), approved for people 65 years and older.

Quadrivalent flu vaccines include:

  • Standard-dose quadrivalent flu shots without adjuvant that are manufactured using virus grown in eggs. Several different brands of this type of flu shot are available, and they are approved for different age groups. Some are approved for children as young as 6 months of age. Most flu shots are given in the arm (muscle) with a needle. One quadrivalent flu shot can be given either with a needle (for people aged 6 months and older) or with a jet injector (for people aged 18 through 64 years only).
  • A quadrivalent cell-based flu shot containing virus grown in cell culture, which is approved for people 4 years and older.
  • A recombinant quadrivalent flu shot (a flu shot that is made without influenza viruses or eggs) approved for people 18 years and older.
  • A quadrivalent live attenuated influenza nasal spray vaccine (LAIV4) made with attenuated (weakened) live flu viruses, approved for use in people 2 years through 49 years of age. This vaccine is not recommended for use in pregnancy or for use among people with some specific medical conditions.

How Do Flu Vaccines Work?

The seasonal flu vaccine protects against the influenza viruses research indicates will be most common during the upcoming season. Antibodies develop in the body about two weeks after vaccination. These antibodies provide protection against infection from flu viruses that are the same as or similar to those used to make the vaccine.

What Viruses Does the 2018-2019 Vaccine Provide Protection Against?

All 2018-2019 influenza vaccines are made to protect against the following three viruses:

  • an A/Michigan/45/2015 (H1N1)pdm09-like virus
  • an A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus
  • a B/Colorado/06/2017-like (Victoria lineage) virus

Some of the 2018-2019 flu vaccine is quadrivalent vaccine and also protects against an additional B virus (B/Phuket/3073/2013-like virus). This is a B/Yamagata lineage virus.

Vaccines that give protection against three viruses are called trivalent vaccines. Vaccines that give protection against four viruses are called quadrivalent vaccines.

More information about influenza vaccines is available at Preventing Seasonal Flu With Vaccination.

If I Got Vaccinated During the 2017-2018 Season, Do I Need to Get Vaccinated This Season?

Yes. CDC recommends a yearly flu vaccine for everyone 6 months and older. This is for two reasons: vaccine compositions may be updated from one season to the next and a person’s immune protection from vaccination declines over time. So an annual vaccination is needed to get the “optimal” or best protection against flu.

When Should I Get Vaccinated?

Optimally, vaccination should occur before onset of influenza activity in the community. Health care providers should offer vaccination by the end of October. Getting vaccinated later, however, can still be beneficial and vaccination should continue to be offered throughout the flu season, even into January or later. Vaccination should continue to be offered as long as influenza viruses are circulating. While seasonal influenza outbreaks can happen as early as October, most of the time influenza activity peaks between December and February. Since it takes about two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection, it is best that people get vaccinated so they are protected before influenza begins spreading in their community.

Protect yourself, your family, and your patients by getting a flu vaccine this season.

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What Is CDC’s Position on Mandating Flu Vaccination for Health Care Workers?

The findings of a CDC review of related published literature indicate that influenza vaccination of health care personnel can enhance patient safety. 1,2

CDC conducts science-based investigations, research, and public health surveillance both nationally and internationally. CDC adopts recommendations that are made by the Advisory Committee for Immunization Practices. These recommendations may be considered by state and other Federal agencies when making or enforcing laws. CDC also has infection control recommendations for health care settings. However, CDC does not issue any requirements or mandates for state agencies, health systems, or health care workers regarding infection control practices, including influenza vaccination or the use of masks.

However, some employers require certain immunizations. Hospitals, for example, may require some staff to get a flu vaccine or hepatitis B vaccine or take other precautions such as the use of masks.

To find out more about the laws in your state and  to contact your state health department through Public Health Resources: State Health Departments.

State Immunization Laws for Healthcare Workers and Patients and Vaccines and Immunizations: Basics and Common Questions National Center for Immunization and Respiratory Diseases have more information. For more information, updates, and access to free materials to assist with educating staff and patients about the impact of influenza and the benefits of vaccination, visit CDC Seasonal Influenza (Flu) or call the National Immunization Hotline at (800) 232-2522 (English), (800) 232-0233 (español), or (800) 243-7889 (TTY).

Special Consideration Regarding Egg Allergy

People with egg allergies can receive any licensed, recommended age-appropriate influenza (flu) vaccine (IIV, RIV4, or LAIV4) that is otherwise appropriate.  People who have a history of severe egg allergy (those who have had any symptom other than hives after exposure to egg) should be vaccinated in a medical setting, supervised by a health care provider who is able to recognize and manage severe allergic reactions.

More Information

Influenza Vaccination Coverage Among Health Care Personnel — United States, 2017–18 Influenza Season. MMWR Morb Mortal Wkly Rep 2018;67(38):1050-1054

Influenza Vaccination Coverage Among Health Care Personnel — United States, 2013–14 Influenza Season. MMWR Morb Mortal Wkly Rep 2014;63:805-11

Influenza Vaccination Performance Measurement Among Acute Care Hospital-Based Health Care Personnel — United States, 2013–14 Influenza Season. MMWR Morb Mortal Wkly Rep 2014; 63:812-5

Health Care Personnel and Flu Vaccination, Internet Panel Survey, United States, November, 2013

Influenza Vaccination Coverage Among Health-Care Personnel — United States, 2012–13 Influenza Season. MMWR Morb Mortal Wkly Rep 2013;62(38);781-786

1 Ahmed F, Lindley M, Allred N, Weinbaum C, Grohskopf L. Effect of Influenza Vaccination of Health Care Personnel on Morbidity and Mortality Among Patients: Systematic Review and Grading of Evidence. Clin Infect Dis 2013; epublished ahead of print.

2 Griffin MR. Influenza Vaccination of Health Care Workers: Making the Grade for Action. Clin Infect Diseases 2013; epublished ahead of print.

Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutionsExternalexternal icon. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD005187. DOI: 10.1002/14651858.CD005187.pub4.

Health Care Personnel Flu Vaccination, Internet Panel Survey, United States, November, 2012

CDC. Influenza Vaccination Coverage Among Health-Care Personnel – 2011-12 Influenza Season, United States. MMWR 2012:61:753-757.

CDC COCA Conference Call. Update on Influenza Vaccination for Health Care Personnel: Recent Coverage, Recommendations, Reporting, and Resources. November 15, 2011.

CDC. Influenza Vaccination Coverage Among Health-Care Personnel—United States, 2010-11 Influenza Season. MMWR 2011;60:1073-1077.

CDC. Telebriefing on Influenza Vaccination Among Health Care Personnel and Pregnant Women. Thursday, August 18, 2011.

Vanhems P, Voirin N, Roche S, Escuret V, Regis C et al. Risk of influenza-like illness in an acute health care setting during community influenza epidemics in 2004-2005, 2005-2006, and 2006-2007: a prospective studyExternalexternal icon. Arch Intern Med 2011; 171(2);151-17.

CDC. Prevention and control of influenza with vaccines. Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2010. MMWR 2010;59(No. RR-8).

Apisarnthanarak A, Uyeki T, Puthavathana P, Kitphati R, Mundy L. Reduction of seasonal influenza transmission among healthcare workers in an intensive care unit: A 4-year intervention study in Thailand. Infect Control Hosp Epidemiol 2010; 31(10);996-1003.

Turnberg W, Daniell W, Duchin J. Influenza vaccination and sick leave practices and perceptions reported by health care workers in ambulatory care settings. Am J Infect Control 2010; 38(6):486-8.

CDC. Influenza vaccination of health-care personnel: recommendations of the Healthcare Infection Control Practices Advisory Committee (HICPAC) and the Advisory Committee on Immunization Practices (ACIP). MMWR 2006;55(No. RR-2).

Salgado CD, Giannetta ET, Hayden FG, Farr BM. Preventing nosocomial influenza by improving the vaccine acceptance rate of clinicians. Infect Control Hosp Epidemiol 2004;25:923–8.

Saito R, Suzuki H, Oshitani H, Sakai T, Seki N, Tanabe N. The effectiveness of influenza vaccine against influenza A (H3N2) virus infections in nursing homes in Niigata, Japan, during the 1998–1999 and 1999–2000 seasons. Infect Control Hosp Epidemiol 2002;23:82–6.

Cunney RJ, Bialachowski A, Thornley D, Smaill FM, Pennie RA. An outbreak of influenza A in a neonatal intensive care unit. Infect Control Hosp Epidemiol 2000;21:449–54.

WF, Elder AG, Wallace LA, et al. Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomised controlled trial. Lancet 2000;355(9198): 93–7.

Saxen H, Virtanen M. Randomized, placebo-controlled double blind study on the efficacy of influenza immunization on absenteeism of health care workers. Pediatr Infect Dis J 1999;18:779–83.

Wilde JA, McMillan JA, Serwint J, Butta J, O’Riordan MA, Steinhoff MC. Effectiveness of influenza vaccine in health care professionals: a randomized trial. JAMA 1999;281:908–13.

Potter J, Stott DJ, Roberts MA, et al. Influenza vaccination of health care workers in long-term-care hospitals reduces the mortality of elderly patients. J Infect Dis 1997;175:1–6.