Should influenza (flu) vaccine be offered to employees even if it is off-season?

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Last updated: May 19, 2025 • View editorial policy

From the Guidelines

Influenza vaccines should still be offered to employees even during the off-season, as vaccination at any time can provide protection for the current or upcoming season. The optimal time for vaccination is before the flu season begins, but late vaccination is particularly important for unvaccinated individuals when influenza viruses are still circulating, as it takes about two weeks after vaccination for antibodies to develop and provide protection 1. For international travelers or those in the Southern Hemisphere, off-season vaccination may align with their destination's flu season. Additionally, maintaining year-round vaccination availability helps accommodate employees with varying schedules and reduces barriers to immunization.

Some key points to consider when offering influenza vaccines to employees during the off-season include:

  • Vaccination efforts should continue throughout the season because the duration of the influenza season varies and influenza activity might not occur in certain communities until February or March 1
  • Providers should offer influenza vaccine routinely, and organized vaccination campaigns should continue throughout the influenza season, including after influenza activity has begun in the community 1
  • The standard influenza vaccine is typically given as a single dose annually, with options including the quadrivalent inactivated vaccine (QIV) for most adults or the high-dose or adjuvanted vaccines for those 65 and older
  • While effectiveness may vary by season and strain match, vaccination remains the most effective strategy for preventing influenza and reducing its severity 1

It's also important to note that health-care facilities should offer influenza vaccinations to all personnel, including night and weekend staff, with particular emphasis on persons who care for members of high-risk groups 2, 3, 4. However, the most recent and highest quality study 1 provides the most relevant guidance for this question.

In terms of the benefits of vaccination, studies have shown that vaccination can provide protection for the current or upcoming season, even when administered during the off-season 1. Additionally, vaccination can help reduce the severity of influenza illness and prevent complications, particularly among high-risk groups.

Overall, offering influenza vaccines to employees during the off-season is a crucial step in preventing influenza and reducing its severity, and employers should prioritize making vaccines available to their employees year-round.

From the Research

Influenza Vaccine Offerings to Employees

  • The influenza vaccine can be instrumental in reducing the burden of influenza on employers, as it can reduce employee absenteeism and yield a positive return on investment 5.
  • Offering the influenza vaccine to employees, even if it's off-season, can still be beneficial in reducing the spread of influenza in the population, with vaccinated employees serving as a barrier to limit the spread of influenza 5.
  • Mandatory vaccination policies or multifaceted campaigns can be effective measures to achieve high overall vaccination coverage among employees, with coverage rates exceeding 90% 6.

Factors Influencing Vaccination Decisions

  • Education and race are significant predictors of influenza vaccine acceptance among employees, with higher education levels and certain racial groups being more likely to accept the vaccine 7.
  • Physician recommendation, vaccine accessibility, and education/messaging are also important factors that can influence an employee's decision to receive the influenza vaccine 7.
  • Employers can use various strategies to boost vaccination rates, including mandatory vaccine policies, requiring non-immunized employees to wear masks, and offering incentives 8.

Vaccine Effectiveness and Types

  • Quadrivalent vaccines, which include both B strains, may be more effective than trivalent vaccines in protecting against influenza, although they are more expensive 9.
  • The effectiveness of the influenza vaccine can vary from season to season, and continued effort is needed to boost vaccination rates among employees 5, 8.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Influenza Vaccination and Healthcare Personnel Compliance.

Current treatment options in infectious diseases, 2020

Research

Evaluating the case for trivalent or quadrivalent influenza vaccines.

Human vaccines & immunotherapeutics, 2016

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.