Vaccine-Preventable Disease Outbreaks among Healthcare Workers: A Scoping Review.

BACKGROUND: Outbreaks of vaccine preventable diseases (VPDs) in health care workers (HCWs) can result in morbidity and mortality and cause significant disruptions to health care services, patients and visitors as well as an added burden on the health system. This scoping review is aimed to describe the epidemiology of VPD outbreaks in HCW, caused by diseases which are prevented by the ten vaccines recommended by World Health Organization (WHO) for HCWs. METHODS: In April 2022 CINAHL, MEDLINE, Global Health and EMBASE were searched for all articles reporting on VPD outbreaks in HCWs since the year 2000. Articles were included regardless of language and study type. Clinical and epidemiological characteristics of VPD outbreaks were described. RESULTS: Our search found 9363 articles, of which 216 met inclusion criteria. Studies describing six of the ten VPDs were found: influenza, measles, varicella, tuberculosis, pertussis and rubella. Most articles (93%) were from high- and upper middle-income countries. While most outbreaks occurred in hospitals, several influenza outbreaks were reported in long term care facilities. Based on available data, vaccination rates amongst HCWs were rarely reported. CONCLUSION: We describe several VPD outbreaks in HCWs from 2000 to April 2022. The review emphasises the need to understand the factors influencing outbreaks in HCWs and highlight importance of vaccination amongst HCWs.

Progress Toward the Elimination of Mother-to-Child Transmission of Hepatitis B Virus - Worldwide, 2016-2021.

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) often results in chronic HBV infection, the leading cause of cirrhosis and liver cancer (1). If not vaccinated, nine in 10 children infected at birth will become chronically infected. Globally, an estimated 6.4 million (range = 4.4-10.8 million) children aged ≤5 years are living with chronic HBV infection (2). In 2016, the World Health Assembly endorsed the goal to eliminate viral hepatitis as a public health threat by 2030, including the elimination of MTCT of HBV (3). Elimination of MTCT of HBV can be validated by demonstrating ≤0.1% prevalence of HBV surface antigen (HBsAg) among children aged ≤5 years, as well as ≥90% coverage with hepatitis B birth dose (HepB-BD) and 3 doses of hepatitis B vaccine (HepB3) (4,5). This report describes global progress toward elimination of MTCT of HBV during 2016-2021. By December 2020, 190 (98%) of 194 World Health Organization (WHO) member states* had introduced universal infant vaccination with hepatitis B vaccine (HepB), and 110 (57%) countries provided HepB-BD to all newborns. During 2016-2020, global HepB3 coverage remained between 82% and 85%, whereas HepB-BD coverage increased from 37% to 43%. In 2020, among the 99 countries reporting both HepB3 and HepB-BD coverage, 41 (41%) achieved ≥90% coverage with both. By December 2021, serosurveys documented ≤0.1% HBsAg prevalence among children in 11 countries. Accelerating HepB-BD introduction, increasing HepB3 coverage, and monitoring programmatic and impact indicators are essential for elimination of MTCT of HBV.

Building global capacity for COVID-19 vaccination through interactive virtual learning.

BACKGROUND: To support the introduction of the COVID-19 vaccine, the World Health Organization and its partners developed an interactive virtual learning initiative through which vaccination stakeholders could receive the latest guidance, ask questions, and share their experiences. This initiative, implemented between 9 February 2021 and 15 June 2021, included virtual engagement between technical experts and participants during a 15-session interactive webinar series as well as web and text-messaging discussions in English and French. METHODS: This article uses a mixed-methods approach to analyze survey data collected following each webinar and a post-series survey conducted after the series had concluded. Participant data were tracked for each session, and feedback surveys were conducted after each session to gauge experience quality and content usability. Chi-square tests were used to compare results across professions (health workers, public health practitioners, and others). RESULTS: The COVID-19 Vaccination: Building Global Capacity webinar series reached participants in 179 countries or 93% of the WHO Member States; 75% of participants were from low- and middle-income countries. More than 60% of participants reported using the resources provided during the sessions, and 47% reported sharing these resources with colleagues. More than 79% of participants stated that this initiative significantly improved their confidence in preparing for and rolling out COVID-19 vaccinations; an additional 20% stated that the initiative "somewhat" improved their confidence. In the post-series survey, 70% of participants reported that they will "definitely use" the knowledge derived from this learning series in their work; an additional 20% will "probably use" and 9% would "possibly use" this knowledge in their work. CONCLUSION: The COVID-19 Vaccination: Building Global Capacity learning initiative used a digital model of dynamic, interactive learning at scale. The initiative enhanced WHO's ability to disseminate knowledge, provide normative guidance, and share best practices to COVID-19 vaccination stakeholders in real time. This approach allowed WHO to hear the information needs of stakeholders and respond by developing guidance, tools, and training to support COVID-19 vaccine introduction. WHO and its partners can learn from this capacity-building experience and apply best practices for digital interactive learning to other health programs moving forward.

Pediatric Investigators Collaborative Network on Infections in Canada Study of Respiratory Syncytial Virus-associated Deaths in Pediatric Patients in Canada, 2003-2013.

Background: Respiratory syncytial virus (RSV) is a major cause of pneumonia and bronchiolitis in children. Mortality rates in previously healthy children hospitalized with RSV are <0.5%, but up to 37% in patients with underlying medical conditions. The objective of this study was to characterize factors associated with deaths among children hospitalized with RSV infection in Canadian pediatric centers. Methods: A retrospective case series of children aged ≤18 years with RSV-associated deaths at centers affiliated with the Pediatric Investigators Collaborative Network on Infections in Canada from 2003­2013, inclusive, was performed [corrected]. Cases were identified using RSV-specific International Classification of Diseases codes to capture deaths where a diagnosis of RSV infection was present. Results: Eleven centers reported 79 RSV-associated deaths. RSV was regarded as primarily responsible for death in 32 cases (40.5%). Median age at death was 11 months (range, <1 month to 16 years). Thirty-nine patients (49.4%) were male. Fourteen patients (17.7%) had no known risk factors for severe RSV infection. Healthcare-associated RSV infections (HAIs) accounted for 29 deaths (36.7%), with RSV judged to be the primary cause of death in 9 of these cases. Conclusions: RSV-associated deaths were predominantly associated with chronic medical conditions and immunocompromised states among infants; however, 1 in 5 deaths occurred among patients with no known risk factors for severe RSV. Mortality associated with HAI accounted for over a third of cases. These findings highlight patient groups that should be targeted for RSV prevention strategies such as infection control practices, immunoprophylaxis, and future vaccination programs.

Progress Toward Rubella and Congenital Rubella Syndrome Control and Elimination - Worldwide, 2000-2018.

Rubella is a leading cause of vaccine-preventable birth defects. Although rubella virus infection usually causes a mild febrile rash illness in children and adults, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or a constellation of birth defects known as congenital rubella syndrome (CRS). A single dose of rubella-containing vaccine (RCV) can provide lifelong protection (1). In 2011, the World Health Organization (WHO) updated guidance on the use of RCV and recommended capitalizing on the accelerated measles elimination activities as an opportunity to introduce RCV (1). The Global Vaccine Action Plan 2011-2020 (GVAP) includes a target to achieve elimination of rubella in at least five of the six WHO regions by 2020 (2). This report on the progress toward rubella and CRS control and elimination updates the 2017 report (3), summarizing global progress toward the control and elimination of rubella and CRS from 2000 (the initiation of accelerated measles control activities) and 2012 (the initiation of accelerated rubella control activities) to 2018 (the most recent data) using WHO immunization and surveillance data. Among WHO Member States,* the number with RCV in their immunization schedules has increased from 99 (52% of 191) in 2000 to 168 (87% of 194) in 2018†; 69% of the world's infants were vaccinated against rubella in 2018. Rubella elimination has been verified in 81 (42%) countries. To make further progress to control and eliminate rubella, and to reduce the equity gap, introduction of RCV in all countries is important. Likewise, countries that have introduced RCV can achieve and maintain elimination with high vaccination coverage and surveillance for rubella and CRS. The two WHO regions that have not established an elimination goal (African [AFR] and Eastern Mediterranean [EMR]) should consider establishing a goal.§.

Vaccine-preventable diseases: Uncommon disease primer for the front-line provider.

This practice point provides quick information for front-line health care providers on vaccine-preventable diseases which, given the success of immunization programs in Canada, are now uncommon or rarely seen. These infections can still occur in children and youth from Canada and elsewhere, and their clinical identification has important public health implications. Knowledge of signs and symptoms, immunizing travellers and newcomers to Canada, awareness of outbreaks in-community and elsewhere, and early consultation with an expert in infectious diseases and public health authorities in suspected cases, are key preventive care measures.

Working with vaccine-hesitant parents: An update.

Most Canadian parents make sure that their children are immunized on time, but health care providers often encounter parents who are hesitant about vaccination or refuse recommended vaccines. This practice point offers evidence-based guidance to clinicians on how to work with vaccine-hesitant parents. Steps include: 1) Understanding the health care provider's key role in parental decision-making and not dismissing vaccine refusers from practice; 2) Using presumptive and motivational interviewing techniques to identify specific vaccine concerns; 3) Using effective, clear language to present evidence for disease risks and vaccine benefits fairly and accurately; 4) Managing pain on immunization; and 5) Reinforcing the importance of and parental responsibility for community protection. Immunization is one of the most important preventive health measures in existence and responsible for saving millions of lives. Addressing the concerns of vaccine-hesitant parents is a priority for health care providers.

Performance of acute flaccid paralysis surveillance compared with World Health Organization standards.

AIM: To compare acute flaccid paralysis (AFP) surveillance systems used by members of the International Network of Paediatric Surveillance Units (INoPSU) across the five AFP surveillance performance indicators recommended by the World Health Organization (WHO) for the maintenance of polio-free certification. METHODS: A survey was administered to AFP surveillance co-ordinators in five INoPSU member countries (Australia, Belgium, Canada, New Zealand and Switzerland). Data collected included information on surveillance system processes, WHO-recommended performance indicators, investigative practices and final diagnoses of cases from 2006 to 2010. RESULTS: All countries contacted completed the survey. Each country used similar case definitions and processes for collecting AFP data. All countries used at least one of the WHO indicators for surveillance. No country consistently met the performance indicator for incidence or stool sampling. In all countries, at least one form of neurological testing was used to diagnose cases of AFP. Guillain-Barré syndrome was the most common final diagnosis in all countries for all years examined. CONCLUSIONS: Industrialised countries surveyed do not consistently meet the WHO-recommended AFP surveillance performance indicators. An opportunity exists for INoPSU to suggest a standard way for member countries to collect AFP data in order to examine the potential for strengthening the current systems or introducing additional enterovirus surveillance or alternative/complementary neurological performance measures suitable for countries that have eliminated polio. INoPSU member countries are evaluating these possibilities.

Canada's National Advisory Committee on Immunization: Celebrating 50 years.

Vaccines have saved more lives than any other innovation in modern medicine. National immunization committees play a vital role in the development of evidence-based recommendations for the use of vaccines. The present article describes the evolution and work of the National Advisory Committee on Immunization in Canada as the group marks its 50th anniversary. The article also provides insight into the future challenges that the committee is likely to face.

Les vaccins ont sauvé plus de vies que n'importe quelle autre innovation de la médecine moderne. Les comités nationaux d'immunisation jouent un rôle essentiel dans la préparation de recommandations fondées sur des données probantes relatives à l'utilisation des vaccins. Le présent article décrit l'évolution et le travail du Comité consultatif national de l'immunisation du Canada, qui célèbre son cinquantième anniversaire. Il contient également un aperçu des prochains défis que le comité devra probablement relever.

National vaccination policies for health workers - A cross-sectional global overview.

BACKGROUND: Immunization is essential for safeguarding health workers from vaccine-preventable diseases (VPDs) that they may encounter at work; however, information about the prevalence and scope of national policies that protect health workers through vaccination is limited. Understanding the global landscape of health worker immunization programmes can help direct resources, assist decision-making and foster partnerships as nations consider strategies for increasing vaccination uptake among health workers. METHODS: A one-time supplementary survey was distributed to World Health Organization (WHO) Member States using the WHO/United Nations Children's Fund (UNICEF) Joint Reporting Form on Immunization (JRF). Respondents described their 2020 national vaccination policies for health workers - detailing VPD policies and characterising technical and funding support, monitoring and evaluation activities and provisions for vaccinating health workers in emergencies. RESULTS: A total of 53 % (103/194) Member States responded and described health worker policies: 51 had a national policy for vaccinating health workers; 10 reported plans to introduce a national policy within 5 years; 20 had subnational/institutional policies; 22 had no policy for vaccinating health workers. Most national policies were integrated with occupational health and safety policies (67 %) and included public and private providers (82 %). Hepatitis B, seasonal influenza and measles were most frequently included in policies. Countries both with and without national vaccination policies reported monitoring and reporting vaccine uptake (43 countries), promoting vaccination (53 countries) and assessing vaccine demand, uptake or reasons for undervaccination (25 countries) among health workers. Mechanisms for introducing a vaccine for health workers in an emergency existed in 62 countries. CONCLUSION: National policies for vaccinating health workers were complex and context specific with regional and income-level variations. Opportunities exist for developing and strengthening national health worker immunization programmes. Existing health worker immunization programmes might provide a foothold on which broader health worker vaccination policies can be built and strengthened.

Leveraging seasonal influenza health worker vaccination programmes for COVID-19 vaccine Introduction: A global qualitative analysis.

BACKGROUND: Health worker vaccination programmes can help to safeguard both health workers (HWs) and their patients and enhance vaccine uptake more broadly in local communities and society. This study's objective was to increase global understanding of how existing HW vaccination programmes were leveraged for emergency COVID-19 vaccine introduction. METHODS: This qualitative study included 13 in-depth group interviews with 38 key informants with expertise in vaccine programme implementation from eleven countries in five WHO regions: Albania, Armenia, Bhutan, Lao PDR, Maldives, Mongolia, Oman, Timor Leste, the United Kingdom, Vietnam, and Zimbabwe in addition to WHO regional focal points from all six regions. These interviews were transcribed, coded, and thematically analyzed. Key informants reviewed the initial results and validated the key findings. RESULTS: Informants characterized key components of both routine and seasonal influenza vaccination programmes that were leveraged for the emergency vaccination of HWs during the COVID-19 pandemic. We identified a set of cross-cutting factors that were used for COVID-19 vaccine roll out: 1) pre-existing occupational health policies, 2) adequate human resources, 3) well-functioning data information systems and vaccine delivery platforms, and 4) established communication channels. Across the eleven countries and six regions interviewed, the ability to adapt existing influenza or other health worker vaccination infrastructure was beneficial for their pandemic response. CONCLUSIONS: Our findings suggest a strong justification for enhanced investment in vaccination of health workers, particularly against seasonal influenza, through country-wide programmes as a foundation for pandemic preparedness and response.

Development of a maturity assessment tool to evaluate and strengthen National Immunization Technical Advisory Groups (NITAGs).

As dozens of new National Immunization Technical Advisory Groups (NITAGs) were established worldwide in the past decade, and as existing NITAGs continued to play an important role in vaccine policy, global NITAG partners recognized a need for a standardized assessment tool to evaluate and strengthen their functions. This article describes the development of the NITAG Maturity Assessment Tool (NMAT), a stepwise evaluation tool that assesses NITAGs on seven key indicators of structure and process. A draft tool was developed through an iterative, consensus-based process with an expert working group before it was piloted with an economically and geographically diverse convenience sample of NITAGs. The final NMAT is a flexible tool that can be used by in-country or external evaluators to understand NITAG maturity, identify priorities for optimization, and measure the impact of strengthening efforts.

Rubella immunity among prenatal women in Ontario, 2006-2010.

BACKGROUND: Countries of the Americas have been working towards rubella elimination since 2003 and endemic rubella virus transmission appears to have been interrupted since 2009. To contribute towards monitoring of rubella elimination, we assessed rubella seroprevalence among prenatal screening tests performed in Ontario. METHODS: Specimens received for prenatal rubella serologic testing at the Public Health Ontario Laboratory, the provincial reference laboratory, between 2006 and 2010 were analyzed. A patient-based dataset was created using all tests occurring among 15-49 year-old females, where prenatal screening was indicated. Multiple tests were assigned to the same patient on the basis of health card number, name and date of birth. Only unique tests performed at least nine months apart were included. SAS version 9.2 was used for analysis. RESULTS: Between 2006 and 2010, we identified 459,963 women who underwent 551,160 unique prenatal screening tests for rubella. Of these, 81.6%, 17.1% and 1.4% had one, two and three or more tests respectively. CONCLUSION: Rubella susceptibility among prenatal women in Ontario supports elimination goals as population immunity in this group is relatively high. Higher susceptibility among young women and women living in the north highlights an opportunity for greater focus on identification and immunization of susceptible women in these groups.

Serotype distribution of invasive Streptococcus pneumoniae in Canada after the introduction of the 13-valent pneumococcal conjugate vaccine, 2010-2012.

The introduction of the 7-valent pneumococcal vaccine (PCV7) in Canada was very effective in reducing invasive pneumococcal disease (IPD) in children; however, increases of non-PCV7 serotypes have subsequently offset some of these reductions. A 13-valent pneumococcal vaccine (PCV13) targeting additional serotypes was implemented between 2010 and 2011, and in 2012 changes in the incidence of disease and the distribution of IPD serotypes began to emerge. The incidence of IPD in children <5 years of age declined from 18.0 to 14.2 cases per 100 000 population between 2010 and 2012; however, the incidence in ages ≥5 years remained relatively unchanged over the 3-year period, at about 9.7 cases per 100 000 population. From 2010 to 2012, PCV13 serotypes declined significantly from 66% (224/339) to 41% (101/244, p < 0.001) in children <5 years of age, and from 54% (1262/2360) to 43% (1006/2353, p < 0.001) in children ≥5 years of age. Serotypes 19A, 7F, 3, and 22F were the most common serotypes in 2012, with 19A decreasing from 19% (521/2727) to 14% (364/2620, p < 0.001), 7F decreasing from 14% (389/2727) to 12% (323/2620, p = 0.04), and 22F increasing from 7% (185/2727) to 11% (279/2620, p < 0.001) since 2010. Serotype 3 increased from 7% (23/339) to 10% (24/244) in <5-year-olds (p = 0.22) over the 3-year period. The highest rates of antimicrobial resistance were observed with clarithromycin (23%), penicillin using meningitis breakpoints (12%), clindamycin (8%), and trimethoprim-sulfamethoxazole (6%). Shifts in the distribution of IPD serotypes and reductions in the incidence of disease suggest that current immunization programs in Canada are effective in reducing the burden of IPD in children. While we acknowledge the limited data on the effectiveness of the PCV13 vaccine, to our knowledge, this study represents one of the first descriptions of the potential impact of the PCV13 vaccine in the Canadian population. Continued surveillance will be important to recognize replacement serotypes, to determine the extent of herd immunity effects in nonpaediatric populations, and to assess the overall effectiveness of PCV13 in reducing IPD in Canada.

A review of health worker vaccination programs in low, middle and upper middle-income countries.

Objectives: Health workers (HW) are at risk of contracting vaccine preventable diseases when caring for patients and communities. This study aims to evaluate the existing literature on the routine vaccination of health workers against a variety of antigens in low and middle income countries, focusing on facilitators, barriers, and considerations in the implementation of immunization programs and campaigns. Study design: A PubMed Literature search. Methods: A PubMed search was conducted to find articles that addressed vaccination programs and policies for HW in low-income countries (LIC), lower middle-income countries (LMIC), and upper middle-income countries (UMIC). Original articles, meta-analyses, and reviews published in English between January 2000 and July 2022 were included in the search. Inductive content analysis was used to identify themes that illustrate facilitators, barriers, and considerations in the implementation of immunization programs and campaigns. Results: The search identified 4240 studies, 90 were used for analysis as they provided antigen specific details on immunization policies or programs. Hepatitis B was the most frequently discussed antigen, followed by Influenza, then Measles, Rubella and Mumps. With considerable variability by vaccine and country, in most cases the vaccination was not offered free to HW or included in a regular vaccination schedule. Utilizing existing immunization infrastructure such as the Expanded Programme on Immunization (EPI) and having effective management of vaccination programs were found to be key facilitators to vaccinate HW. Conclusions: The low vaccination coverage of health workers in LMIC is of concern; attention towards the key considerations, barriers and facilitators of immunization implementation is central to the advancement of health worker vaccination coverage in LMIC's. The COVID-19 pandemic necessitated the swift vaccination of HW. Many LIC countries lacking established HW immunization infrastructure are now administering COVID-19 vaccines. As we move beyond the pandemic's acute phase, there is a chance for those countries to enhance their immunization initiatives and policies for HW concerning other antigens, even if it is not a standard practice currently.

COVID-19 vaccine policy development in a sample of 44 countries - Key findings from a December 2021 survey of National Immunization Technical Advisory Groups (NITAGs).

National Immunization Technical Advisory Committees (NITAGs) are tasked with the responsibility of guiding ministries of health and national immunization programmes in their policy development processes. Many NITAGs rely on evidence reviewed by the World Health Organization's (WHO) Strategic Group of Experts(SAGE) on immunization and aim to adapt WHO's recommendations to their respective contexts. This relationship took on exceptional importance since the onset of the COVID-19 pandemic, during which NITAGs have expressed a notable struggle to craft appropriate policies on population prioritization and vaccine utilization in the face of supply constraints and complex programmatic and delivery logistics. This online survey was conducted to assess the usefulness of the SAGE guidance documents for COVID-19 vaccine policies and to examine the persisting needs and challenges facing NITAGs. Results confirmed that SAGE recommendations concerning COVID-19 vaccines are easy to access, understand, and adapt. They have been found to be comprehensive and timely under the data and time constrained circumstances confronting SAGE. The Global NITAG Network (GNN) appears to be the most popular vehicle for addressing questions among high income countries, in contrast to lower income countries who favour WHO Country or Regional Offices. NITAGs place much value on interaction with other NITAGs, which requires facilitation and could benefit from increased opportunities, especially within regions. It is further noted that some NITAGs have had to tackle issues during the pandemic not typically considered by SAGE, such as supply chain logistics and vaccine demand. Learning from the COVID-19 experience offers opportunities to strengthen NITAGs and the pandemic recovery effort through the development of more concrete procedures and consideration of more varied types of data, including implementation effectiveness and uptake data. There is also an opportunity for an increasing involvement of Country Office WHO personnel to support NITAGs, while ensuring information and evidence needs of countries are adequately reflected in SAGE deliberations.

Health workers vaccination: Experience and lessons learned from Costa Rica.

Objective: To describe the decision-making processes, enablers, challenges and lessons learned in Costa Rica for implementing a sustained and multi-pronged approach in health workers vaccination (HW). Methods: A retrospective descriptive analysis was conducted by searching published and grey literature, including scientific publications, legislation, decrees, policies, manuals, technical reports, and platforms used for data register and coverage monitoring. Key informants from the Ministry of Health (MoH), the Costa Rican Social Security Fund (CCSS) were interviewed representing national, subnational and local levels; as well as members of the National Technical Advisory Group (NITAG) and the private sector. Collected data were transcribed and categorized by the following specific topics using a thematic content analysis approach: decision making process, pre-service screening, vaccination for current HWs and engagement with the private sector. Major findings were discussed and organized into enablers, challenges and lessons learned. Results: Decision making processes to establish the vaccination strategies and schedules in Costa Rica were based on the epidemiological trends of vaccine-preventable diseases (VPDs) and cost analysis. Risk assessment and feasibility considerations determined that some vaccines such as hepatitis B, varicella and influenza, were first introduced in HWs and then were expanded to other target populations. These decisions were approved by the NITAG as the advisory technical advisory group of the MoH. Main enablers identified were: high level and sustained political will, decisions based on data analysis and feasibility considerations, HWs knowledge and high vaccine acceptance and demand. Challenges were related to effective coverage monitoring, and private sector engagement. Conclusions: The Costa Rican experience provides lessons learned that can be leveraged by other countries to strengthen HWs vaccination strategies at regional and global levels.

Epidemiology of invasive Haemophilus influenzae serotype a disease in the North American Arctic, 2006-2017.

Invasive Haemophilus influenzae type a (iHia) disease was detected in Alaska and Northern Canada in 2002 and 2000, respectively. From 2006 to 2017, 164 iHia cases (Alaska=53, Northern Canada=111) were reported. Rates of iHia disease per 100,000 persons were higher in Northern Canada compared to Alaska and were significantly higher in Indigenous (Alaska 2.8, Northern Canada 9.5) compared to non-Indigenous populations (Alaska 0.1, Northern Canada=0.4). Disease rates were highest in Indigenous children <2 years of age (Alaska 56.2, Northern Canada=144.1) and significantly higher than in non-Indigenous children <2 (Alaska 0.1, Northern Canada 0.4). The most common clinical presentation in children <5 years was meningitis of age and pneumonia in persons ≥5 years old. Most patients were hospitalised (Alaska=87%, Northern Canada=89%) and fatality was similar (Alaska=11%, Northern Canada=10%). MLST testing showed sequence types ST23 and ST576 in Northern Canada and ST576, ST23 and ST56 in Alaska. Alaska and Northern Canada have high rates of iHia disease. A vaccine is needed in these regions to protect young children.

Estimating the health workforce requirements and costing to reach 70% COVID-19 vaccination coverage by mid-2022: a modelling study and global estimates.

OBJECTIVES: The implementation of COVID-19 vaccination globally poses unprecedented stress to health systems particularly for countries with persisting health workforce shortages prior the pandemic. The present paper estimates the workforce requirement to reach 70% COVID-19 vaccination coverage in all countries by mid-2022 using service target-based estimation. METHODS: Health workforce data from National Health Workforce Accounts and vaccination coverage reported to WHO as of January 2022 were used. Workload parameters were used to estimate the number of health workers needed with a service target-based approach, the gap and the scale-up required partially accounting for countries' challenges, as well as the associated costs in human resources. RESULTS: As of 1 January 2022, only 34 countries achieved 70% COVID-19 vaccination coverage and 61 countries covered less than a quarter of their population. This analysis showed that 1 831 000 health workers working full time would be needed to reach a global coverage of 70% COVID-19 vaccination by mid-2022. To avoid severe disruptions to health system, 744 000 additional health workers should be added to domestic resources mostly (77%) in low-income countries. In a sensitivity analysis, allowing for vaccination over 12 months instead of 6 months would decrease the scale-up to 476 000 health workers. The costing for the employment of these 744 000 additional health workers is estimated to be US$2.5 billion. In addition to such a massive scale-up, it is estimated that 29 countries would have needed to redeploy more than 20% of their domestic workforce, placing them at serious risk of not achieving the mid-year target. CONCLUSION: Reaching 70% global coverage with COVID-19 vaccination by mid-2022 requires extraordinary efforts not before witnessed in the history of immunisation programmes. COVID-19 vaccination programmes should receive rapid and sustainable investment in health workforce.