Timely rollout and widespread uptake of safe and effective vaccines will be necessary to reduce mortality, improve health outcomes, restore societal well‐being and inspire economic recovery from the coronavirus disease (COVID‐19) pandemic. Unprecedented efforts to accelerate vaccine development have resulted in the emergency or expedited approval of several COVID‐19 vaccines [1]. The Australian Government has secured access to both the Pfizer and the University of Oxford/AstraZeneca vaccines and plans to commence a national COVID‐19 vaccine rollout in early 2021. Phase 1a of the program will immunise priority populations, including frontline health‐care workers, quarantine and border staff and aged care and disability care residents and staff [2]. This will be followed by Phase 1b, delivering doses to people aged over 70 years, Aboriginal and Torres Strait Islander people aged over 55 years, younger adults with underlying medical conditions and critical and high‐risk workers [3]. These priority populations are similar to those identified in international vaccination efforts [4].

The Australian Technical Advisory Group on Immunisation (ATAGI) has specified those with an increased risk of developing severe disease or dying from COVID‐19, including people with pre‐existing select medical conditions, as priority populations for immunisation [5]. The ATAGI also noted that communities of low socioeconomic status and those belonging to culturally and linguistically diverse backgrounds are at increased risk of adverse health outcomes from COVID‐19 based on international data [5]. While the Commonwealth has provided in‐principle agreement to prioritise people living with human immunodeficiency virus (HIV) for vaccination during Phases 1a and 1b, the Australian Society for HIV Medicine, along with relevant peak bodies, is also advocating to ensure the strategy appropriately prioritises people living with all blood‐borne viral infections [6].

Although only one in four people infected with SARS Cov2, the virus that causes COVID‐19, have comorbidities, 60–90% of those hospitalised have physical health comorbidities [7]. People reporting problematic use of alcohol and other drugs may represent a high‐risk population in this respect, given their high prevalence of comorbid health conditions [8]. In particular, people who inject drugs (PWID) may be at elevated risk of adverse outcomes from COVID‐19 given their high prevalence of underlying medical conditions, including respiratory and pulmonary disease, chronic liver disease, cardiovascular disease, cerebrovascular disease, diabetes and compromised immunity [9, 10]. Importantly, such conditions may be underdiagnosed in this population [11, 12].

Early data also indicate that COVID‐19 has had a significant impact on patterns of injection drug use and service uptake. Interviews with 884 PWID recruited from Australian capital cities in mid‐2020 showed that 1 in 10 (12%) reported difficulties accessing sterile needles and syringes since COVID‐19 restrictions were introduced [13]. Among 1324 PWID attending Australian needle and syringe programs (NSP) surveyed in late 2020, the same proportion (12%) reported that they had found it more difficult to access NSP. Of those who last injected an opioid (n = 588), 5% reported starting depot buprenorphine, 15% had started or increased the number of takeaway opioid agonist treatment doses, and 26% had accessed take‐home naloxone since the start of the pandemic (Australian NSP Survey 2020, unpublished data).

However, compared to the general population, PWID have low rates of vaccine uptake and completion, including for hepatitis B [14]. A recent survey of 872 Australian PWID found that only 24% reported being vaccinated for the 2020 influenza season (i.e. since March 2020) [15]—significantly lower than the 49% of the general population who reported vaccination between January and May 2020 [16]. In relation to hypothetical acceptability of a COVID‐19 vaccine, 57% of a sample of 100 PWID interviewed in Melbourne in December 2020 indicated that they would ‘definitely’ or ‘probably’ get vaccinated were a vaccine available [17]. However, 15% indicated that they would ‘definitely not’ get the vaccine and 20% were undecided. While the most frequently nominated concerns were related to vaccine safety, and anti‐vaccination beliefs were rare, COVID vaccine acceptability was lower than the 77% observed in a recent poll of the general population [18]. These data indicate the need for increased efforts to inform PWID about vaccine efficacy and safety to reduce hesitancy and uncertainty and increase acceptability.

The logistics of reaching and vaccinating PWID are not insignificant. While the Australian government is responsible for selecting, purchasing and transporting vaccines and specifying priority populations, state and territory governments are responsible for providing the vaccine delivery workforce and identifying specific vaccination sites. Vaccination locations that have been identified include general practice (GP), GP respiratory clinics, dedicated vaccination clinics, workplace clinics, locations identified by the Aboriginal and Torres Strait Islander Community Controlled Health sector, pharmacies and in‐reach vaccination for aged care facilities and ‘other vulnerable people or targeted populations who cannot access another location’ [5].

It will be important to have a range of effective methods of vaccine rollout targeting PWID and other vulnerable groups, including incarcerated populations. Despite being at higher risk of a wide range of physical and mental health disorders [19], PWID are under‐served in relation to primary health care and are more likely to present late, increasing the risk of significant mortality and morbidity [20, 21]. PWID are also over‐represented among emergency department presentations [22, 23]. A study of 2395 Australian PWID found that emergency departments were the health provider most recently accessed by 14% of respondents [24]. A pilot project that placed a nurse‐led mobile immunisation service at locations accessed by vulnerable populations in Australia, including homeless shelters and an NSP, successfully increased the uptake of influenza vaccine [25]. Along with emergency departments, NSP, homeless shelters/temporary accommodation and prisons provide important access points to PWID; with an appropriately trained and qualified immunisation workforce and resources, including access to anaphylaxis management, these services could potentially be tasked to access and provide opportunistic vaccination to this population.

With an estimated 1280 publicly funded alcohol and other drug (AOD) treatment services [26] and 2950 opioid agonist treatment (methadone and buprenorphine) dosing points [27] in Australia, AOD treatment services and dosing points also provide an important touchpoint for COVID‐19 immunisation rollout to vulnerable populations, ideally as sites for vaccination and, at minimum, as settings for education and referral. A recent study found that PWID who reported being vaccinated for influenza in the past year were more likely to be enrolled in opioid agonist treatment [15]. Contact with the health system through AOD treatment is also an important way to communicate health messages designed to increase vaccine confidence. AOD treatment providers, especially those with specialist peer workers, have the infrastructure and experience with low literacy health communications to work with clients to encourage cooperation with public health messages and recommendations, reduce misunderstanding and improve knowledge.

Consideration of other evidence‐based strategies, such as conditional cash transfers or contingency management, may also be necessary to ensure that COVID‐19 vaccines reach PWID in a timely manner, especially because effective immunisation will require two doses within a specified time frame. Our randomised trial of per‐dose incentives for hepatitis B vaccine completion found that PWID randomised to the incentive condition were more than three times more likely to complete the series than those randomised to the control condition [28]. The use of incentives to encourage vaccine uptake and completion by PWID has also been adopted by the World Health Organization [29]. People with lived experience of injecting drug use have an essential role to play in informing and driving strategies to maximise vaccination uptake; community‐led networks must be key partners in developing and delivering vaccination systems and strategies [30]. While the strong engagement with scientific research and a commitment to best practice helps to ensure that Australia's services are well placed to interact with the drug‐using community, bolstering community infrastructure and resources to disseminate information and build trust and confidence will be crucial to this engagement.

For many vulnerable communities, including PWID, COVID‐19 represents a pandemic on top of one or more epidemics [31], and the constant need for vigilance and risk reduction on multiple fronts is challenging and exhausting. In times of crisis, these communities face challenges such as being unable to access health services or receiving the same quality of health care as others due to high rates of social and economic disadvantage, homelessness and criminalisation, as well as low health literacy and stigma and discrimination from health‐care providers [10]. Consistent with the right to science, there is a need for public access to the knowledge and products of science in this pandemic [32]. Equity of access to interventions to prevent, diagnose and treat COVID‐19 means ensuring that vaccines are accessible and available free of charge to everyone everywhere, especially those who are under‐served and at increased risk of adverse health outcomes [33]. Given strong peer networks, high coverage of treatment and harm reduction interventions [34, 35], and the availability of other access points, which could serve as settings for COVID‐19 immunisation and/or points of contact for vaccine education and referral, Australia is well positioned to ensure PWID are not left behind.

有必要及时推出和广泛采用安全有效的疫苗，以降低死亡率、改善健康状况、恢复社会福祉并激发经济从冠状病毒病 (COVID-19) 大流行中复苏。加速疫苗开发的空前努力已导致紧急或加速批准几种 COVID-19 疫苗 [ 1 ]。澳大利亚政府已确保获得辉瑞和牛津大学/阿斯利康的疫苗，并计划在 2021 年初开始在全国范围内推广 COVID-19 疫苗。该计划的第 1a 阶段将对包括一线卫生保健工作者在内的重点人群进行免疫接种，检疫和边境工作人员以及老年护理和残疾护理居民和工作人员 [ 2]。随后是第 1b 阶段，向 70 岁以上的人、55 岁以上的原住民和托雷斯海峡岛民、有潜在疾病的年轻人以及危重和高风险工人提供剂量 [ 3 ]。这些优先人群与国际疫苗接种工作中确定的人群相似 [ 4 ]。

澳大利亚免疫技术咨询小组 (ATAGI) 已将那些患有严重疾病或死于 COVID-19 的风险增加的人（包括患有预先存在的特定疾病的人）指定为免疫接种的优先人群 [ 5 ]。ATAGI 还指出，根据国际数据 [ 5]。虽然联邦政府原则上同意在第 1a 和 1b 阶段优先接种人类免疫缺陷病毒 (HIV) 感染者，但澳大利亚 HIV 医学学会与相关高峰机构也在倡导确保该战略适当地优先考虑患有所有血源性病毒感染的人 [ 6 ]。

尽管只有四分之一的感染 SARS Cov2（导致 COVID-19 的病毒）的人患有合并症，但 60-90% 的住院患者有身体健康合并症 [ 7 ]。报告有问题使用酒精和其他药物的人在这方面可能代表高危人群，因为他们的合并症患病率很高[ 8 ]。特别是，注射吸毒者 (PWID) 可能面临更高的 COVID-19 不良后果风险，因为他们患有基础疾病，包括呼吸和肺部疾病、慢性肝病、心血管疾病、脑血管疾病、糖尿病和受损免疫 [ 9, 10 ]。重要的是，这种情况在该人群中可能未被充分诊断[11、12 ]。

早期数据还表明，COVID-19 对注射吸毒模式和服务吸收产生了重大影响。对 2020 年中期从澳大利亚首府城市招募的 884 名 PWID 进行的采访表明，自 COVID-19 限制措施实施以来，十分之一 (12%) 的人报告说难以使用无菌针头和注射器 [ 13 ]。在 2020 年底接受调查的 1324 名参加澳大利亚针头和注射器计划 (NSP) 的 PWID 中，同样比例 (12%) 的人报告说他们发现获得 NSP 更加困难。最后一次注射阿片类药物的人（n= 588），5% 的人报告开始储存丁丙诺啡，15% 的人已经开始或增加外卖阿片受体激动剂治疗剂量的数量，自大流行开始以来，26% 的人使用了带回家的纳洛酮（澳大利亚 NSP 调查 2020，未发表的数据） .

然而，与普通人群相比，PWID 的疫苗接种率和完成率较低，包括乙型肝炎 [ 14 ]。最近对 872 名澳大利亚 PWID 进行的一项调查发现，只有 24% 的人报告在 2020 年流感季节（即自 2020 年 3 月以来）接种了疫苗 [ 15 ]——明显低于 2020 年 1 月至 5 月期间报告接种疫苗的 49% 的普通人群 [ 16 ] ]。关于 COVID-19 疫苗的假设可接受性，2020 年 12 月在墨尔本接受采访的 100 名 PWID 样本中有 57% 表示，如果有可用的疫苗，他们将“肯定”或“可能”接种疫苗 [ 17]。然而，15% 的人表示他们“绝对不会”接种疫苗，20% 的人尚未决定。虽然最常被提名的担忧与疫苗安全有关，而且抗疫苗接种的信念很少，但 COVID 疫苗的可接受性低于最近对普通人群进行的一项民意调查中观察到的 77% [ 18 ]。这些数据表明需要加大力度向 PWID 通报疫苗的有效性和安全性，以减少犹豫和不确定性并提高可接受性。

到达和接种 PWID 的后勤工作并非微不足道。澳大利亚政府负责选择、购买和运输疫苗并指定优先人群，而州和领地政府则负责提供疫苗运送人员并确定特定的疫苗接种地点。已确定的疫苗接种地点包括全科诊所 (GP)、GP 呼吸诊所、专门的疫苗接种诊所、工作场所诊所、由原住民和托雷斯海峡岛民社区控制的卫生部门确定的地点、药房和老年护理设施的可及疫苗接种地点和“其他无法进入其他地点的弱势人群或目标人群”[ 5 ]。

拥有一系列针对 PWID 和其他弱势群体（包括被监禁人群）的有效疫苗推广方法非常重要。尽管 PWID 患多种身心健康障碍的风险较高 [ 19 ]，但 PWID 与初级卫生保健相关的服务不足，并且更有可能出现迟到，从而增加了显着死亡率和发病率的风险 [ 20, 21 ]。PWID 在急诊科的报告中也出现过多 [ 22, 23 ]。一项针对 2395 名澳大利亚 PWID 的研究发现，急诊科是 14% 的受访者最近访问的医疗服务提供者 [ 24]。一项试点项目在澳大利亚弱势群体可访问的地点（包括无家可归者收容所和 NSP）放置由护士主导的移动免疫服务，成功地增加了流感疫苗的使用 [ 25 ]。与急诊部门一起，NSP、无家可归者收容所/临时住所和监狱为 PWID 提供了重要的入口；有了经过适当培训和合格的免疫工作人员和资源，包括获得过敏反应管理，这些服务可能会负责为该人群提供机会性疫苗接种。

据估计，澳大利亚有 1280 个公共资助的酒精和其他药物 (AOD) 治疗服务 [ 26 ] 和 2950 个阿片受体激动剂治疗（美沙酮和丁丙诺啡）给药点 [ 27 ]，AOD 治疗服务和给药点也为 COVID‐ 19 向弱势群体推广免疫接种，理想情况下作为疫苗接种场所，至少作为教育和转诊场所。最近的一项研究发现，在过去一年中报告接种过流感疫苗的 PWID 更有可能参加阿片受体激动剂治疗 [ 15]。通过 AOD 治疗与卫生系统联系也是传达旨在提高疫苗信心的健康信息的重要方式。AOD 治疗提供者，尤其是那些拥有专业同行工作人员的治疗提供者，拥有与低文化健康沟通的基础设施和经验，可以与客户合作，鼓励与公共卫生信息和建议合作，减少误解并提高知识。

考虑其他基于证据的策略，例如有条件的现金转移或应急管理，也可能是确保 COVID-19 疫苗及时到达 PWID 的必要条件，特别是因为有效的免疫接种需要在指定的时间范围内接种两剂。我们对完成乙型肝炎疫苗的每剂量激励的随机试验发现，随机分配到激励条件下的 PWID 完成该系列的可能性是随机分配到控制条件下的三倍以上 [ 28 ]。世界卫生组织也采用了鼓励 PWID 接种和完成疫苗的激励措施 [ 29]。具有注射吸毒生活经验的人在告知和推动战略以最大限度地提高疫苗接种率方面发挥着重要作用；社区主导的网络必须成为开发和提供疫苗接种系统和战略的关键合作伙伴 [ 30 ]。虽然大力参与科学研究和对最佳实践的承诺有助于确保澳大利亚的服务能够很好地与吸毒社区互动，但加强社区基础设施和资源以传播信息并建立信任和信心对于这种参与至关重要.

对于包括 PWID 在内的许多弱势社区而言，COVID-19 代表了一种或多种流行病之上的流行病 [ 31 ]，并且在多个方面持续保持警惕和降低风险的需求是具有挑战性和令人筋疲力尽的。在危机时期，这些社区面临着挑战，例如由于社会和经济劣势率高、无家可归和刑事犯罪率高，以及健康素养和污名低下，无法获得医疗服务或获得与其他人相同质量的医疗保健。来自医疗保健提供者的歧视 [ 10 ]。与科学权相一致，在这一流行病中，公众需要获取科学知识和产品 [ 32]。公平地获得预防、诊断和治疗 COVID-19 的干预措施意味着确保世界各地的每个人都可以免费获得疫苗，尤其是那些服务不足和面临不良健康后果风险增加的人 [ 33 ]。鉴于强大的同行网络、治疗和减害干预措施的高覆盖率 [ 34、35 ] 以及其他接入点的可用性，这些接入点可以作为 COVID-19 免疫接种的设置和/或疫苗教育和转诊的联络点，澳大利亚处于有利位置，以确保 PWID 不会落伍。