Protecting our frontline: vaccination policies for health care workers in the Americas

ABSTRACT

Objective:

This paper explores vaccination policies for health care workers (HCWs) in effect in all 35 Pan American Health Organization (PAHO) countries plus the British territory of Anguilla to highlight strengths and challenges within the region and inform relevant policies and interventions.

Methods:

Data were collected in two phases. Phase 1 (March–September 2021) was conducted as part of a global survey examining characteristics of national vaccination policies for HCWs. The questions addressed policy enforcement, antigens included in policies, funding, vaccination monitoring, and emergency vaccination plans. Respondents were representatives from 21 countries. In Phase 2 (March–August 2023), 15 country representatives who did not respond to the initial survey completed an amended, web-based version of the original questionnaire.

Results:

Of the 36 countries, 15 (42%) reported having a national HCW vaccination policy, and 3 (8%) planned to introduce one within 5 years. Among those with policies, 80% integrated them into occupational health regulations. All policies covered influenza and hepatitis B, while many also included tetanus, measles, rubella, diphtheria, and COVID-19. Over half of respondents had emergency vaccination mechanisms, and 44% reported national monitoring systems. Ten countries had comprehensive vaccination policies for HCWs.

Conclusions:

To strengthen HCW vaccination policy in the Americas, future efforts should support countries in developing tailored national policies, expanding antigen coverage—especially for outbreak-prone diseases—and investing in strong monitoring systems. Additionally, scaling up behavioral research, enhancing communication strategies, and institutionalizing emergency mechanisms will be critical for addressing vaccine hesitancy and ensuring both pandemic preparedness and routine care continuity.

Vaccinating health care workers (HCWs) (1) against vaccine-preventable diseases is essential for several reasons. The World Health Organization defines health workers as “all people engaged in actions whose primary intent is to enhance health.” This broad definition acknowledges that not only front-line providers, but also nonclinical staff, play essential roles in maintaining safe and effective health systems (1). Vaccination protects workers’ health while preventing transmission of illnesses to vulnerable patients and community members (2–4). Vaccinated workers also are less likely to miss work due to illness (5, 6). HCWs are often recognized as trusted sources of information about vaccines and vaccination (3) and personal vaccination status strongly predicts whether a HCW will recommend vaccination to their patients (7).

The World Health Organization (WHO) recommends HCWs receive vaccines that are part of their national routine vaccination schedule and additional vaccines against diseases that they may be exposed to in the workplace (3, 8). WHO vaccination recommendations for HCWs encompass annual seasonal vaccinations (3, 8, 9), emergency and/or outbreak vaccinations (3, 10), and vaccines to guard against occupational health hazards (3, 11). According to WHO, all HCWs should have documented proof of immunity or vaccination for recommended vaccines and documentation should be required as a condition of employment and prior to beginning training (3).

In alignment with the WHO Strategic Advisory Group of Experts (SAGE) recommendations, the Pan American Health Organization (PAHO) Technical Advisory Group (TAG) recommends the prioritization of HCWs for vaccination against influenza, COVID-19, and hepatitis B (12–14). The PAHO TAG also endorses measles and diphtheria vaccines for HCWs (15). Strategic Line of Action number 5 of the Regional Immunization Action Plan for the Americas 2030, Strengthen human resource capacities for immunization programs, includes the objective: “Ensure the availability of an adequate, effective, sustainable, and vaccinated health workforce” (16). Given the shared accountability across the health system for workforce development, a more targeted indicator of immunization program contribution is the existence and implementation of vaccination policies for HCWs.

In the Region of the Americas, persistent challenges such as workforce shortages, unequal distribution of vaccines, and occupational risks have highlighted the urgent need to strengthen policies that support and protect HCWs (17). One vital yet often under-implemented component of these policies is ensuring vaccination for HCWs, which is essential for both worker safety and patient protection.

Many countries have vaccination recommendations for HCWs. However, there is considerable variation in the details, such as whether recommendations are formalized policies, antigens included, the level of authority at which they are enforced (e.g., national, state or institutional level), implementation strategy (mandatory, voluntary, or mixed), and whether guidelines pertain to all HCWs or specific subgroups (2, 18–24). This variability is a challenge that could compromise health worker safety, while also undermining broader efforts toward health system resilience and universal health coverage.

STUDY PURPOSE AND OVERVIEW

Understanding policy-related challenges is critical to supporting evidence-based policymaking and targeted interventions. This paper explores vaccination policies for HCWs that were in effect in all 36 PAHO countries¹ to highlight strengths and challenges within the region. Results of this project will be used to inform vaccination policy guidelines for HCWs in the Americas and corresponding interventions. This report classifies the survey findings using core themes from WHO’s Implementation guide for vaccination of health workers: policy framework, vaccination strategies, confidence and demand (i.e., factors which influence vaccine uptake, such as convenience, accessibility, and risk perception), and monitoring (i.e., systems and processes in place to track HCW vaccination status and estimate coverage) (3).

MATERIALS AND METHODS

Survey Instrument and Implementation

Data were collected in two phases: Phase 1 data were collected between March 1 and September 30, 2021, as part of the WHO and the United Nations Children’s Fund (UNICEF) global survey to assess WHO Member States’ HCW vaccination policies (18). The Phase 1 data collection instrument was a Microsoft Excel-based supplemental survey distributed in conjunction with the Joint Reporting Form (JRF). The survey included multiple choice and open-ended questions to identify which countries in calendar year 2020 had national policies regarding HCW vaccination, the nature of and funding support (if any) for those policies, monitoring, communication and evaluation activities, and whether countries had a plan in place to vaccinate health workers in an emergency. The survey addressed 12 antigens for which WHO had published specific recommendations for HCWs (Bacille Calmette-Guerin [BCG]; hepatitis B; polio; diphtheria; measles; rubella; meningococcus A, C, W, Y; meningococcus B; meningococcus C; seasonal influenza; varicella; pertussis) and three often included in national vaccination schedules (hepatitis A, mumps, tetanus) (8, 18). Respondents had the opportunity to write in additional vaccines included as part of their country-specific policy. Although WHO conducted a global analysis on HCW vaccination policies and published its findings, the Region of the Americas was underrepresented, with data from only 21 countries included (18). Given the importance of understanding how to address this issue at the regional level effectively, this study undertook a complementary survey to gather more comprehensive and specific information. Phase 2 data were collected between March 29 and August 24, 2023, using English and Spanish versions of an online version of the original collection tool (Qualtrix; Provo, UT), amended to include specific items about COVID-19 and yellow fever vaccines (which were the most frequent write-in responses to the first survey) and designed to enforce skip patterns to avoid inconsistent answers (which was not possible with the Excel instrument). Phase 2 of data collection targeted country representatives who did not respond to the Phase 1 survey (n = 15).

DATA PREPARATION AND ANALYSIS

Since PAHO had access to the original survey database, the first step was to clean the data, which involved logic checks to identify disparate and missing responses. Queries were sent to country representatives to clarify missing or inconsistent information. Inconsistent responses to the questionnaire that were not addressed during the consultation period were analyzed as provided, with multiple and contradictory responses treated as missing data.

Responses from both data collection phases were consolidated in a single analytic file and Spanish responses were translated into English. Several variables from the Phase 1 questionnaire were recoded to ensure data from the two phases were coded uniformly. Descriptive analyses were conducted to quantify the number and percentage of PAHO countries reporting key HCW vaccination policy characteristics, including policy type. Antigen-level analysis assessed inclusion in national policies, designation for specific HCW groups, implementation status, and administration sites. The analysis also captured country-level reporting on HCW vaccination strategies, efforts to promote vaccine confidence and demand, and monitoring practices. Using the criteria established by Young et al. for identifying countries with well-functioning comprehensive vaccination programs for HCWs (18), the authors tabulated the number of PAHO countries that met all four criteria: (1) policy includes multiple antigens; (2) country has a mechanism for introducing a vaccine to HCWs in an emergency or outbreak response situation; (3) country has a system for recording and reporting vaccination uptake among HCWs; and (4) national vaccination policy for HCWs is integrated with occupational health policy.

The number of respondents who answered each survey question varied because not all items were relevant to every country. For instance, questions related to specific policy characteristics applied only to countries with a national policy (n = 15). Additionally, some respondents did not answer all questions. In the summary tables, missing responses and responses of “don’t know” are classified as “no data.” For Figures 1b–1d, the denominator used to calculate each proportion was the number of countries that included the antigen in their national policy. Data were analyzed using Stata version 18 (Stata Statistical Software: Release 18. College Station, TX: StataCorp LLC).

RESULTS

Respondents

Survey respondents were representatives from 36 PAHO Member States responsible for completing the JRF for the reporting period of January to December 2020. Twenty-one respondents completed the survey during the Phase 1 data collection period² and 15 completed the survey during Phase 2. The survey achieved a 100% response rate across both phases of the study, as each PAHO Member State had a representative who submitted a response. Respondents were predominantly Expanded Programme on Immunization (EPI) managers (50%), EPI professionals, and managers of broader health programs.

Vaccination Policy Characteristics

Policy Framework

The characteristics of PAHO countries’ policies to vaccinate HCWs are summarized in Table 1. Fifteen of 36 countries (42%) reported having a national vaccination policy for HWs and 3 countries (8%) reported having plans to introduce a policy in the next 5 years. Although they lacked a unified national policy, 4 countries reported having subnational policies (11%) and 11 reported having policies at the institutional level (31%). Three countries (8%) reported no specific vaccination policy for HCWs.

TABLE 1. Characteristics of PAHO countries’ vaccination policies for health care workers: policy framework (regional summary).

Vaccination policy characteristics	Countries with characteristic
Policy Framework	n	Percentage
Vaccination policy typea (n = 36)
Yes, there is a national policy	15	42%
No national policy, but there are subnational policies	4	11%
No national policy, but there are policies at an institutional level	11	31%
No national policy, but country plans to introduce health care worker (HCW) policy in the next 5 years	3	8%
No policy/don’t know	3	8%
No data	1	3%
National vaccination policy is integrated into occupational health policy for HCWa (n = 15)
Yes	12	80%
No	3	20%
Scope of national policy (n = 15)
Applies to public providers only	3	20%
Applies to private providers only	0	0%
Applies to public and private providers	12	80%
Availability of vaccination services for HCWs at the workplace (n = 15)
Yes	12	80%
No	3	20%
Funding for mandatory vaccinesb (n = 15)
Government-funded (National Immunization Program)	9	60%
Self-pay	0	0%
Other	1	7%
No data	5	33%
Funding for voluntary vaccinesc (n = 15)
Government-funded (National Immunization Program)	12	80%
Self-pay	4	27%
Other	2	13%
No data	1	7%

Source: Original table for this article.

^aSome respondents selected more than one option.

^bMandatory vaccinations: required to work in a health care setting.

^cVoluntary vaccinations: recommended but left to the discretion of the individual.

Of the 15 countries with a national policy, 12 (80%) reported that the policy was integrated into occupational health policy for HCWs and the same percentage reported that the scope of their national policy applied to both public and private providers. Twelve countries with a national policy (80%) reported that vaccination services were available for HCWs at the workplace. Many countries with a national policy reported that funding for both mandatory (60%) and voluntary (80%) vaccines were funded by the government’s national immunization program.

The characteristics of national vaccination policies are summarized by vaccine antigen in Figure 1. Among the 15 countries with a national policy, all policies included seasonal influenza and hepatitis B. Other antigens frequently included in countries’ national policies were tetanus (80%), measles (73%), rubella (73%), diphtheria (67%), and COVID-19 (67%) (Figure 1a). When antigens were included in the national policy, they were commonly intended for all HCWs, except for BCG, poliomyelitis, yellow fever, and pertussis (Figure 1b). Regarding policy implementation, diphtheria and yellow fever were the vaccines most frequently mandated for HCWs (50%), followed by hepatitis B (47%), tetanus (42%), and seasonal influenza, pertussis, and tetanus (33%). Meningococcus C was the vaccine most likely to be treated as voluntary (100%), followed by COVID-19 (90%), and meningococcus B (67%) (Figure 1c). Antigens were primarily administered in the workplace, except for BCG (25%), poliomyelitis (25%), and meningococcal ACWY vaccines (20%) (Figure 1d).

FIGURE 1. Characteristics of national vaccination polices by vaccine antigen, among PAHO countries with a national policy (n = 15).

Source: Original figure for this article.

BCG: Bacillus Calmette-Guerin. Men: Meningococcus.

^aMandatory vaccinations: required to work in a health care setting.

^bVoluntary vaccinations: recommended but left to the discretion of the individual.

^cMixed vaccination policies: mandatory vaccination policies for specific health settings or categories of HCWs and voluntary in other cases.

Policy Comprehensiveness

Table 2 summarizes the characteristics of PAHO countries’ vaccination policies concerning HCWs, including vaccination strategies, efforts to promote vaccine confidence and demand, and strategies for monitoring vaccine uptake.

TABLE 2. Characteristics of PAHO countries' vaccination policies for HCWs: vaccination strategies, confidence and demand, and monitoring strategies (regional summary).

Vaccination policy characteristics	Countries with characteristic
HCW vaccination strategies	n	Percentage
Policy includes routine vaccinations which all HCWs receive (n = 15)
Yes	13	87%
No	2	13%
Policy includes annual or periodic vaccines (e.g., seasonal influenza) (n = 15)
Yes	15	100%
No	0	0%
Mechanism for introducing a vaccine to HCWs in an emergency or outbreak response (n = 36)
Yes	19	53%
No	5	14%
No data	12	33%
If mechanism is in place, did it exist before the COVID-19 pandemic? (n = 19)
Yes	16	84%
No	3	16%
Confidence and demand
Communication activities to promote vaccination among HCWs (past 5 years) (n = 36)
Yes	21	58%
No	3	8%
No data	12	33%
Evaluations of vaccine demand or acceptance among HCWs (past 5 years) (n = 36)
Yes	10	28%
No	15	42%
No data	11	31%
Behavioral and social assessments of reasons for under-vaccination of HCWs (n = 36)
Yes	3	8%
No	20	56%
No data	13	36%
Monitoring
National system to monitor notification of vaccine adoption among HCWs (n = 36)
Yes	16	44%
No	7	19%
No data	13	36%

Source: Original table for this article.

HCW Vaccination Strategies

Among countries with a national policy, nearly all recommended routine vaccinations (87%) and all policies included annual or periodic vaccines such as seasonal influenza. More than half of all PAHO countries reported having a mechanism in place for introducing a vaccine to HCWs in an emergency or outbreak response situation (53%). Among countries with such a mechanism, it was generally in place before the COVID-19 pandemic (84%).

Confidence and Demand

Fifty-eight percent of PAHO countries reported conducting communication activities such as national information campaigns and distribution of published National Immunization Technical Advisory Group (NITAG) recommendations to promote vaccination within the past 5 years. Twenty-eight percent of countries reported conducting an evaluation of vaccine demand or acceptance among HCWs during the past 5 years. Three countries reported conducting a behavioral and social assessment of the reasons for under vaccination of HCWs (8%).

Monitoring

Forty-four percent of PAHO countries reported having a national system for monitoring and reporting vaccination uptake among HCWs.

Policy Comprehensiveness

Ten PAHO countries—Argentina, Bolivia, Brazil, Chile, Costa Rica, Cuba, Mexico, Panama, Paraguay, and Uruguay—met the four criteria for a comprehensive vaccination program for HCWs: (1) policy includes multiple antigens; (2) country has a mechanism for introducing a vaccine to HCWs in an emergency or outbreak response situation; (3) country has a system for recording and reporting vaccination uptake among HCWs; and (4) national vaccination policy for HCWs is integrated with occupational health policy (18). Five countries reported having some combination of the core characteristics for a comprehensive policy (Figure 2).

FIGURE 2. Policy comprehensiveness (regional summary).

Source: Original figure for this article.

DISCUSSION

This study explores vaccination policies for HCWs that were in effect in all 36 PAHO countries (21 Member States in 2020 and 15 in 2023). It examines selected policy characteristics, including antigens covered, HCW vaccination strategies, efforts to promote confidence and demand, and monitoring, to highlight strengths and challenges within the region. HCWs are the foundation of any health system; therefore, ensuring they are protected from vaccine-preventable diseases should be a priority. Results of this project will be used to inform vaccination policy guidelines for HCWs in the Americas and relevant interventions.

Key Findings, Comparisons with Global Policy Trends, and Recommendations

Half of PAHO countries reported having a national policy to vaccinate HCWs or expected to introduce a policy in the next 5 years. This percentage (50%) was higher than the percentage of countries globally with the same characteristics (61/194; 31%) (18). Across WHO regions, the Region of the Americas was second only to the European Region in the prevalence of national vaccination policies for HCWs (18).

Among Member States that have implemented national vaccination policies, several best practices emerged. For example, a majority (80%) have integrated HCW vaccination into occupational health frameworks with government funding, applying these policies to both public and private health care providers to reduce the barriers to immunization access for HCWs, including providing workplace vaccination (25). WHO has urged countries to build institutional capacities that include occupational health and safety (26). Integrating immunizations within this larger framework emphasizes the role vaccination plays in creating safe work environments for HCWs. Importantly, 60% and 80% of countries funded mandatory and voluntary vaccines, respectively, through national immunization budgets, suggesting that financing is not a major limiting factor among countries with established policies.

In PAHO countries with a national policy, the number of vaccine antigens in the schedule varied widely—from countries with only two vaccines to those whose schedules contained 15 antigens. Most antigens were designated for all HCWs rather than any specific subgroup. In agreement with WHO (8–10) and PAHO TAG (12–15) guidelines, all countries with a national vaccination policy for HCWs included both seasonal influenza and hepatitis B in their schedules, and a majority included COVID-19. However, many PAHO countries’ policies did not include polio, meningococcal vaccines, and/or BCG, which are also among the vaccines WHO recommends for HCWs (8). Countries should promote using WHO- and PAHO-recommended vaccines for all HCWs to keep HCWs safe from other vaccine-preventable diseases.

More than half of PAHO countries reported having mechanisms for emergency or outbreak-specific vaccination for health personnel (53%). While this is slightly below the global figure (60%), it indicates that the region possesses a framework capable of supporting rapid response immunization efforts, as evidenced by PAHO’s strong response to the COVID-19 pandemic (27). Member States should continue to establish or strengthen mechanisms to introduce vaccines during emergencies or outbreaks.

The percentage of PAHO countries who reported conducting an assessment of demand or uptake among HCWs in the past 5 years was higher than the percentage observed globally (28% vs. 21%) (18). Assessment of the behavioral and social drivers (BeSD) of vaccination using published tools (28) would facilitate cross-county comparisons and sharing of relevant resources and lessons learned. Assessment efforts could be done in conjunction with World Immunization Week (29), with results used by EPI programs and others to tailor interventions to specific regions to promote the likelihood of success.

Monitoring and data collection remain under development in the region: fewer than half of PAHO Member States reported having a national system in place to monitor notification of vaccine coverage among HCWs (44% vs. 42% globally) (18). Without routine monitoring, countries are limited in their ability to identify coverage gaps, respond to emerging threats, or evaluate program effectiveness. Because maintaining HCW vaccination records and monitoring coverage is essential for health care safety and public health preparedness (30), it will be important to expand monitoring systems to strengthen HCW vaccination programs. Utilizing digital tools is a promising approach for enhancing immunization coverage and tracking vaccination status (31) and could also be beneficial for monitoring the vaccination status of HCWs.

Although 10 countries met the criteria for a comprehensive vaccination program for HCWs (18), there is room for growth. PAHO compares favorably with other WHO Member States (28% of PAHO countries with a comprehensive policy vs. 13% globally). An example of a model comprehensive policy is Costa Rica’s, which mandates vaccinations for HCWs based on occupational risk under its National Vaccination Law and includes eight antigens, all of which are mandatory. All vaccines administered by the Costa Rican Social Security Fund (Caja Costarricense de Seguro Social, CCSS), including those given to HCWs, are registered in the Integrated Health Registry System (EDUS) in a vaccination data module. In Costa Rica, the process for introducing a vaccine to HCWs during an emergency outbreak is coordinated by the CCSS, in collaboration with the Ministry of Health (32).

The heterogeneity in national policies reflects broader regional challenges in aligning immunization practices with international standards. In many countries, decentralization of health services was cited as a barrier, with subnational or institutional policies sometimes substituting for national frameworks. While these approaches may offer flexibility, they often lead to inequities in HCW protection and fragmented data.

Lack of a coherent vaccination policy is a barrier to HCW vaccination efforts (33). Going forward, therefore, it will be important to provide technical support to countries who lack resources to support a comprehensive program with a holistic framework that addresses all four critical components (18), supplemented with efforts to promote vaccine confidence and demand (28). Policies should be tailored and strengthened by selecting the interventions that best address the needs of the country’s population (34), with consideration for current epidemiologic trends in vaccine-preventable diseases (20) as well as cultural and legislative issues (2).

Study Strengths and Limitations

A key strength of this study is that responses were received from all PAHO Member States, augmenting the previous survey 21 survey WHO summary (18).

Although the study reflects responses from all PAHO countries, a limitation is that many respondents did not provide responses to all questions. The survey data were based on unvalidated self-reports about national policies. The study is further limited by the fact that Phase 1 and Phase 2 data were collected 2 years apart using different survey instruments.

Conclusion

Vaccination of HCWs is critical for protecting them, their patients, and members of the community, and enables the continuity of health services that might be affected by the occurrence of vaccine-preventable diseases in HCWs. This survey provides a regional picture of vaccination policies for HCWs in the Americas. Although this region compared favorably to others globally, there is still ample opportunity for policy strengthening in countries that have programs and introduction for those countries that do not currently have HCW policies for immunization.

To strengthen HCW vaccination in the Americas, future efforts should focus on several key areas. First, governments without national policies should be supported to formulate creative ways to develop and implement them. Second, countries with existing policies should work to expand antigen coverage, particularly for outbreak-prone diseases. Third, investments are needed in robust national monitoring systems to track vaccine uptake and identify coverage gaps. Fourth, behavioral and social research should be scaled up to better understand and address vaccine hesitancy among HCWs. Finally, strengthening communication strategies and institutionalizing emergency vaccination mechanisms will be essential for pandemic preparedness and routine immunization continuity. To facilitate this process, we should ensure country leaders are aware of PAHO/WHO immunization program resources available to guide policy decisions (3, 8, 9).

Given significant shifts to the vaccination policy landscape following the COVID-19 pandemic (35), a follow-up survey of immunization program staff exploring current vaccination policies and their implementation for HCWs in the Americas would be informative. Examining published vaccination policies, policy adherence, vaccination coverage rates, and evaluations that may have been done across the region to validate survey findings could also be useful for assessing gaps and areas for improvement.

Funding Statement

This work was sponsored by PAHO through flexible funding: the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Disclaimer.

Authors hold sole responsibility for the views expressed in the manuscript, which may not necessarily reflect the opinion or policy of the RPSP/PAJPH and/or PAHO.