2023 年沒有 COVID 自滿的餘地
來自中國的嚴酷景象顯示，大流行遠未結束。 一種解決方案是像激光一樣專注於加強公共衛生系統。
資料來源：社論/2022 年 12 月 23 日/自然/財團法人台灣紅絲帶基金會編譯
人們在北京一家藥店外排隊等待 COVID-19 治療。 模型顯示，中國 2023 年的死亡人數可能高達 100 萬。
圖片來源：Kevin Frayer/Getty
隨著各國放棄大流行控制措施，許多地方的生活在 2022 年呈現出 COVID 前的正常狀態。 各國政府結束了封鎖，重新開放了學校，並縮減或放棄了戴口罩的規定。 國際旅行恢復。
也有樂觀的宣言。 1 月，丹麥首相梅特·弗雷德里克森宣布 SARS CoV-2 不再對社會構成威脅。 9月，美國總統拜登在接受采訪時表示，疫情已經結束。 就連世界衛生組織 (WHO) 秘書長譚德塞 (Tedros Adhanom Ghebreyesus) 也表示希望 COVID-19 被指定為全球緊急事件的做法將於 2023 年結束。
這掩蓋了該疾病繼續造成的破壞。 最明顯的例子是在中國，面對快速傳播的 Omicron 變異株，中國是最後放鬆大流行控制措施的國家之一。 現在從中國醫院出現的場景讓人想起近一年前 Omicron 在香港造成的浩劫。 無論習近平主席是否在 12 月放棄清零 COVID 政策，中國都可能已經出現廣泛傳播。 但模型顯示，該國明年將面臨多達 100 萬人死亡的前景，更不用說普遍的工作場所缺勤和對中國乃至全球經濟的破壞。
大多數中國人對 Omicron 這一目前流行的主要毒株在免疫學上毫無準備。 他們沒有接觸過任何 SARS-CoV-2 變異株，如果接種疫苗，也只接種了針對該病毒原始毒株的疫苗。 中國可能會發現過去一年中其他接觸該病毒有限的國家所發現的情況：不會有單一的「退出」浪潮來標誌著大流行限制的解除。 接下來可能會出現更多的感染和死亡浪潮，這可能是由於人口中出現的新變種，也可能是由於該國向遊客開放邊境時進口的變種。
需要重新作出回應
在其他地方，感染和死亡的反復激增正在讓位於持續不斷的損失以及長期 COVID 導致的衰弱。 對 COVID-19 的關注也影響了對抗愛滋病、瘧疾和結核病的工作。 儘管很難獲得精確計數，但許多國家/地區的總體死亡率仍高於 COVID-19 襲擊之前。
許多國家的 COVID-19 疫苗接種率停滯不前。 在一些國家，追加劑的使用情況令人沮喪，儘管這些大大減少了死亡和嚴重疾病。
更新疫苗接種工作的一種途徑在於技術。 粘膜疫苗的開發正在進行中。 這些被設計成透過鼻子或嘴巴傳遞，希望它們能觸發阻斷感染的免疫來防止傳播——而不僅僅是嚴重的疾病。 中國已經批准了一種可吸入的加強劑和一種鼻腔疫苗，而印度則批准了一種兩劑滴鼻初級疫苗。 伊朗和俄羅斯也各自批准了一種粘膜疫苗。 但研究人員正在等待數據，以檢查其中任何一項是否兌現了阻止 SARS-CoV-2 的承諾。
可能動搖 COVID 自滿情緒的一件事，是一種或多種「令人關注的變異株」（VoC）的出現。該病毒就像它們在 2022 年那樣，新變異株亦將在明年出現。但是，只有當新變異株能夠更有效地逃避免疫系統、導致更嚴重的疾病或比目前傳播的疾病更具傳染性。 針對新的 「令人關注的變異株」(VoC ) 必須激發採取行動，確保完全接種疫苗的人——尤其是老年人或免疫功能低下的人——接受追加劑量。
一種新「令人關注的變異株」（VoC）還必須促使低收入國家加倍進行疫苗接種。 COVAX 等全球合作的建立是為了公平地提供疫苗。 但隨著富裕國家優先為自己的人口接種疫苗，使這機制變得步履蹣跚。 低收入和中等收入國家 (LMIC) 的疫苗往往是零星交付的，而且接近到期日期，這加劇了在醫療保健基礎設施有限的地方推廣疫苗的挑戰。
結果是低收入國家只有四分之一的人至少接種了一劑冠狀病毒疫苗。 許多低收入國家需要重新解決被忽視的優先事項，例如瘧疾、肺結核和嬰兒死亡率，所有這些都在大流行病最嚴重的時期被擱置。 但忽視 COVID-19 的持續威脅之風險也有可能阻礙這些努力。
國際社會必須正視那些破壞確保所有國家在需要時都能獲得疫苗之倡議的政治和權力動態。 除非如此，否則在未來全球的協議可能會在危機時期再次受到類似的破壞。 5 月，世界衛生組織的政府間談判機構將提交一份關於大流行防範和應對國際文書（最接近條約的東西）的審議進展報告。那些錯過及時獲得 COVID-19 疫苗、測試和治療的國家將會爭辯要求說，該協議應確保在下一次大流行威脅出現時能更公平地獲得資源。
但是，隨著注意力轉移到應對「X 病」——一種可能導致下一次大流行的迄今未知的病原體——COVID 的自滿情緒正在導致醫療保健系統在過去三年中遭受上千次削減，從而導致死亡。 公共衛生界必須繼續加強中低收入國家的疫苗生產能力。 而且它絕不能忘記自 2020 年以來的經驗顯示：處於壓力之下的醫療保健系統幾乎無法應對新的威脅。
自然 613, 7 (2023)；doi: https://doi.org/10.1038/d41586-022-04476-9
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.
EDITORIAL/23 December 2022/Nature
People queue outside a Beijing pharmacy for COVID-19 treatments. Models suggest China could see up to one million deaths in 2023.Credit: Kevin Frayer/Getty
In 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