There’s no room for COVID complacency in 2023
Stark scenes from China show the pandemic is far from over. One solution is a laser-like focus on strengthening public-health systems.
n many places, life took on a semblance of pre‑COVID normality in 2022, as countries shed pandemic-control measures. Governments ended lockdowns, reopened schools and scaled back or abandoned mask-wearing mandates. International travel resumed.
There were optimistic proclamations, too. In January, Danish Prime Minister Mette Frederiksen declared that SARS‑CoV-2 no longer poses a threat to society. In September, US President Joe Biden remarked during an interview that the pandemic was over. Even Tedros Adhanom Ghebreyesus, director-general of the World Health Organization (WHO), has expressed hope that COVID-19’s designation as a global emergency will end in 2023.
This belies the devastation that the disease continues to cause. The starkest example is in China, one of the last countries to ease pandemic-control measures in the face of the fast-spreading Omicron variant. Scenes emerging from Chinese hospitals now are reminiscent of the havoc that Omicron wrought in Hong Kong nearly a year ago. China might have seen widespread transmission regardless of whether President Xi Jinping had dropped the zero-COVID policy in December. But models suggest that the country faces the prospect of up to one million deaths over the next year, not to mention widespread workplace absences and disruptions to the Chinese — and global — economy.
Most people in China are immunologically unprepared for Omicron, the dominant strain now in circulation. They have had no exposure to any SARS-CoV-2 variant and, if vaccinated, have received vaccines only against the virus’s original strain. China is likely to discover what other countries with limited previous exposure to the virus have found over the past year: that there won’t be a single ‘exit’ wave to mark the lifting of pandemic restrictions. Further waves of infection and death are likely to follow, either from new variants that arise in the population, or from variants imported as the country opens its borders to visitors.
Renewed responses needed
Elsewhere, repeated surges in infection and death are giving way to a constant thrum of loss, as well as debilitation caused by long COVID. A focus on COVID-19 has also affected the fights against AIDS, malaria and tuberculosis. Although precise counts are difficult to obtain, overall death rates in many countries remain higher than before COVID-19 hit.
COVID-19 vaccination rates have stalled in many nations. In some, the uptake of boosters has been dismal, even though these substantially reduce death and severe illness.
One path to renewing vaccination efforts lies with technology. Development of mucosal vaccines is under way. These are designed to be delivered through the nose or mouth and it’s hoped they can trigger sterilizing immunity that blocks transmission — not just severe illness. China has approved an inhalable booster dose and a nasal vaccine, and India a two-dose nasal-drop primary vaccine. Iran and Russia have also each approved a mucosal vaccine. But researchers are awaiting data to check whether any of these deliver on their promise of stopping SARS-CoV-2.
One thing that could shake COVID complacency is the emergence of one or more ‘variants of concern’ (VoCs). New variants of the virus will emerge over the next year, as they did in 2022. But a VoC designation (and a corresponding Greek letter from the WHO) will be given only if a variant is better at evading the immune system, causes more severe disease or is much more transmissible than those currently circulating. A new VoC must spur action to ensure that fully vaccinated people — especially those who are older or immunocompromised — receive booster doses.
A new variant must also prompt redoubled vaccination efforts in lower-income nations. Global collaborations, such as COVAX, were established to deliver vaccines equitably. But they faltered as wealthy nations prioritized vaccinating their own populations. Too often, vaccines for low- and middle-income countries (LMICs) were delivered sporadically and close to their date of expiry, exacerbating the challenge of rolling them out in places with limited health-care infrastructure.
The result is that only one-quarter of people in low-income countries have received at least one dose of a coronavirus vaccine. Many low-income countries need to get back to tackling neglected priorities such as malaria, tuberculosis and infant mortality, all of which were sidelined as the worst of the pandemic swept through. But ignoring COVID-19’s continued toll risks stymieing these efforts, too.
The global community must reckon with the politics and power dynamics that undermined initiatives to ensure that all nations had access to vaccines when they needed them. Unless that happens, future global agreements could be similarly undermined in times of crisis. In May, the WHO’s intergovernmental negotiating body will deliver a progress report on deliberations over an international instrument — the nearest thing to a treaty — on pandemic preparedness and response. Countries that missed out on timely access to COVID-19 vaccines, tests and treatments will be arguing that the agreement should ensure more equitable access to resources when the next pandemic threat emerges.
But as attention moves to preparations for ‘disease X’ — the as-yet-unknown pathogen that could cause the next pandemic — COVID complacency is inflicting death by a thousand cuts on health-care systems reeling from the past three years. The public-health community must continue to strengthen vaccine-manufacturing capacity in LMICs. And it mustn’t forget what experience has shown since 2020: that health-care systems under stress are little able to deal with new threats.
Nature 613, 7 (2023)
doi: https://doi.org/10.1038/d41586-022-04476-9
在许多地方，随着各国放弃大流行病控制措施，2022年的生活呈现出一种COVID之前的正常状态。政府结束了封锁，重新开放学校，缩减或放弃了戴口罩的规定。国际旅行恢复了。
也有一些乐观的声明。1月，丹麦首相Mette Frederiksen宣布，SARS-CoV-2不再对社会构成威胁。9月，美国总统乔-拜登在接受采访时说，这场大流行病已经结束。甚至世界卫生组织（WHO）总干事Tedros Adhanom Ghebreyesus也表示，希望COVID-19被指定为全球紧急情况将在2023年结束。
这掩盖了该疾病继续造成的破坏性。最明显的例子是在中国，面对快速传播的Omicron变体，中国是最后放松大流行病控制措施的国家之一。现在从中国医院出现的场景让人想起近一年前Omicron在香港造成的破坏。无论习近平主席是否在12月放弃了清零政策，中国都可能出现广泛的传播。但是模型显示，中国在未来一年面临着多达一百万人死亡的前景，更不用说大范围的工作场所缺勤和对中国–以及全球–经济的干扰了。
中国的大多数人对Omicron，即现在流行的主要菌株没有免疫准备。他们没有接触过任何SARS-CoV-2的变体，如果接种疫苗，也只接种了针对该病毒原始变体的疫苗。中国很可能会发现，过去一年里，其他以前接触过该病毒的国家也发现：不会有一个单一的 “退出”浪潮来标志着大流行限制的解除。进一步的感染和死亡浪潮可能会接踵而来，要么是人口中出现的新变种，要么是随着中国向游客开放边界而输入的变种。
需要新的反应
在其他地方，感染和死亡的反复激增正在让位于持续的损失，以及长期COVID造成的衰弱。对COVID-19的关注也影响了对艾滋病、疟疾和结核病的斗争。虽然很难获得精确的数字，但许多国家这些疾病的总体死亡率仍然高于COVID-19袭击之前。
许多国家的COVID-19疫苗接种率已经停滞。在一些国家，加强针的接受率一直很低，尽管这可以大大减少死亡和严重疾病。
恢复疫苗接种工作的一个途径在于技术。粘膜疫苗的开发正在进行中。这些疫苗被设计为通过鼻子或嘴来传递，希望它们能够引发杀菌免疫力，阻止传播，而不仅仅是预防重症。中国已经批准了一种可吸入的加强剂量和一种鼻腔疫苗，印度则批准了一种两剂量的鼻腔滴注初级疫苗。伊朗和俄罗斯也分别批准了一种粘膜疫苗。但研究人员正在等待数据，以检查这些疫苗是否能实现其阻止SARS-CoV-2的承诺。
有一件事可以动摇COVID的自满情绪，那就是出现一个或多个 “值得关注的变体”（VoCs）。该病毒的新变种将在明年出现，就像在2022年一样。但是，只有当一个变体能更好地躲避免疫系统、导致更严重的疾病或比目前流行的变体更具传播性时，才会被指定为VoC（以及世卫组织的相应希腊字母）。新的VoC必须促使人们采取行动，确保充分接种疫苗的人——特别是那些年龄较大或免疫力低下的人——接受加强剂量。
一个新的变体还必须促使低收入国家加倍努力进行疫苗接种。建立全球合作，如COVAX，是为了公平地提供疫苗。但是，由于富裕国家优先考虑为自己的人口接种疫苗，这些合作出现了动摇。为中低收入国家（LMICs）提供的疫苗往往是零星的，而且临近到期日，加剧了在卫生保健基础设施有限的地方推广疫苗的挑战。
其结果是，低收入国家只有四分之一的人至少接种了一剂冠状病毒疫苗。许多低收入国家需要重新处理被忽视的优先事项，如疟疾、结核病和婴儿死亡率，所有这些都在最严重的大流行病席卷而来时被搁置一边。但是，忽视COVID-19的持续损失也有可能阻碍这些努力。
全球社会必须正视那些破坏了确保所有国家在需要时都能获得疫苗的举措的政治和权力动态。除非这样做，否则未来的全球协议在危机时期也会受到同样的破坏。5月，世卫组织的政府间谈判机构将提交一份关于大流行病防备和应对的国际文书（最接近条约）的审议进展报告。错过了及时获得COVID-19疫苗、测试和治疗的国家将争辩说，该协议应确保在下一次大流行威胁出现时更公平地获得资源。
但是，随着人们的注意力转移到对 “X疾病”——可能导致下一次大流行的未知病原体——的准备工作上，COVID的自满情绪正在给过去三年中疲于奔命的卫生保健系统带来千疮百孔的后果。公共卫生界必须继续加强中低收入国家的疫苗制造能力。而且，它不能忘记2020年以来的经验表明：处于压力之下的医疗系统几乎没有能力应对新的威胁。