同心抗疫接種疫苗 群體免疫護己護人
全球新冠肺炎疫情前景仍然嚴峻，印度、馬來西亞等地出現嚴重爆發，加上病毒不斷變種，雖然本地感染數字持續偏低，但可以預料，如果香港沒有達到群體免疫，第五波、第六波疫情將再度來襲。接種疫苗是遏止疫情的重要一環，香港醫學會在此呼籲社會各界，盡快接種新冠疫苗，一起建立群體免疫屏障，保護自己及身邊親友，是戰勝疫情的唯一希望。
- 新冠疫苗安全且有效，更是唯一能令市民免受新冠病毒感染的方法。高接種率的國家如以色列（63.2%*）、英國（60.2%*）及美國（51.5%*），其感染及死亡數字均大幅下降。英國由去年十二月開始大規模接種疫苗，疫情由最高峰的每日逾六萬宗新症，下降至平均每日約八千多宗[1]。美國的感染數字亦由一月份最高峰每日25萬宗，減至每日一萬五千宗以下[2]。截至五月底，全球已有4.3億[3]人完成接種兩劑疫苗。除了已知的副作用，全球均沒有出現因疫苗引起的大型事故，可見新冠疫苗不僅能有效減低感染率，而且安全性亦受到肯定。
- 按世界衞生組織（世衛）指，疫苗接種異常事件是指接種疫苗後發生的任何醫療事件，並不一定與疫苗使用有因果關係。市民在接收這方面的資訊時，要與這些疾病的背景發生率一併理解。根據醫管局及衛生署的數字，2019年每日因缺血性心臟病、腦血管病及糖尿病死亡的平均人數分別達10.2人、8.1人及1.4人；2020年因心肌梗塞及急性缺血性中風入院的數字分別約為7,300宗及10,300宗[4]；2017至2019年間，每年約有3,500至3,900人次自然流產[5]。現時接種疫苗者的相關疾病發生比率並未超出預期，可見這些疾病並非罕見，亦非全然與接種疫苗有關。
- 香港感染數字持續偏低，令部分市民對疫情放下戒心，更有不少誤解認為長戴口罩及保持社交距離是持久可行的防疫策略。事實上，不少疫情長期受控，甚至已「清零」的國家／地區如新加坡、台灣等，近月亦出現了大規模爆發。有意見認為，台灣的疫情與該地疫苗接種率低有部分關係。台灣因市民對疫苗猶豫及疫苗量不足等原因，截至五月，僅2.3%（約46萬）[6]人接種兩劑疫苗。加上疫苗存貨嚴重不足，在當地疫情爆發後，疫苗更是一針難求，難以在短期內建立群體免疫。香港市民必須引以為鑑，勿以為口罩及社交距離便可提供足夠保護，特別是仍有部分市民未有正確戴上口罩（如經常拉下或觸摸口罩）及使用酒精搓手液。大眾須在疫苗存貨量充足時盡快接種疫苗，才能有效保護自己及身邊人。
- 不少市民憂慮疫苗未能有效抵禦變種病毒（受關注病毒變異株，已命名為Alpha, Beta, Gamma, Delta），部分更希望等待第二代疫苗才考慮接種。事實上，香港提供的疫苗均對變種病毒有一定保護作用。英國一項初期研究發現復必泰對印度變種病毒（B.1.617.2）的效力達88%，對英國變種病毒（B.1.1.7）的效力則為93%[7]；而卡塔爾的研究數據顯示，接種兩劑復必泰疫苗的人士，患上由南非變種病毒（B.1.351）引起的新冠肺炎的可能性降低75%[8]。至於科興疫苗，巴西研究發現完成兩劑接種後，科興疫苗對巴西變種病毒（P.1）有症狀感染的預防率約為 50%[9]。重要的是，疫苗能大幅減低感染者的重症徵狀及死亡率，即使受到感染，亦能大大減低接種者患上重症及死亡的風險。
- 不少人寄望本地感染數字「清零」後，便可逐漸回復正常生活。但若香港仍維持在低接種水平，可以預期的是，戴口罩、維持社交距離等措施將會持續。在各國往來上，其他歐美國家已逐漸朝著群體免疫的目標前進，可預見這些國家將來可通關，開放予同樣已達成群體免疫的國家公民出入境。然而，在社區沒有足夠的免疫屏障下，即使香港個案「清零」，亦將無法放寬通關限制，旅遊、國際商務等活動將繼續停擺，市民的人身自由亦將繼續受限。
新冠疫情將會是一場持久戰，而疫苗是目前能戰勝疫情、讓市民生活回復正常的唯一希望。香港醫學會呼籲市民以科學理據為考量、以公眾健康作為出發點，盡快接種疫苗，一起同心打贏這一仗！
二零二一年六月十五日
*為已接種至少一劑疫苗的人口比例，資料來源：https://ourworldindata.org/covid-vaccinations?country=OWID_WRL年6月9日。
[1] 數字為2021年6月9日的7天移動平均值，資料來源：https://coronavirus.data.gov.uk/details/cases。
[2] 數字為2021年6月9日的7天移動平均值，資料來源：https://covid.cdc.gov/covid-data-tracker/#trends_dailytrendscases。
[3] 資料來源：https://ourworldindata.org/covid-vaccinations?country=OWID_WRL，2021年5月31日。
[4] 資料來源：https://www.info.gov.hk/gia/general/202103/09/P2021030900703p.htm，2021年3月9日。
[5] 資料來源：https://www.info.gov.hk/gia/general/202104/14/P2021041400576p.htm，2021年4月14日。
[6] 資料來源：https://www.scmp.com/news/china/science/article/3135734/coronavirus-taiwan-step-vaccination-drive-2-million-doses-arrive，2021年6月2日。
[7] 資料來源：https://www.gov.uk/government/news/vaccines-highly-effective-against-b-1-617-2-variant-after-2-doses，2021年5月22日。
[8] 資料來源：https://www.nature.com/articles/d41586-021-01222-5，2021年5月6日。
[9] 資料來源：https://www.nature.com/articles/s41577-021-00556-5，2021年5月10日。
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15 June 2021
Support Vaccination Together, Build Herd Immunity, Protect Loved Ones
The global COVID-19 pandemic situation is still evolving. With severe outbreaks in India, Malaysia and other nearby countries, coupled with the continuous mutation of the virus, it is foreseeable that if Hong Kong does not achieve herd immunity, the fifth and sixth waves of outbreaks will strike again despite the low level of local infection now. Vaccination is an important tool to help stop the pandemic, the Hong Kong Medical Association (HKMA) hereby urges the society to get vaccinated as soon as possible to build herd immunity in the city and protect ourselves and our loved ones.
- The COVID-19 vaccines are proven to be safe and effective, and it is the only way to develop immunity against the COVID-19 virus. Countries with high vaccination rates, such as Israel (63.2%*), the UK (60.2%*) and the US (51.5%*), show significant declines in their COVID-19 infections and related deaths. The UK started mass vaccination in December last year, and their infection cases have dropped from a peak of more than 60,000 cases per day to the current average of 8,000 cases per day[10]. The number of infections in the US has also fallen from the highest 250,000 cases per day to below 15,000 cases per day[11]. As of May, 430 million[12] people worldwide have completed two doses of vaccine. Except for the known side effects, there have been no major medical incidents caused by vaccines globally. It can be seen that the COVID-19 vaccine not only can offer substantial protection, but also its safety has been affirmed.
- According to the World Health Organization (WHO), an adverse event following immunization (AEFI) is any untoward medical occurrence that follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. When the public receives information about AEFI, it is essential to consider the background incidence rate of these events all along. According to the figures from the Hospital Authority and the Department of Health, in 2019, the average daily deaths due to ischemic heart disease, cerebrovascular disease, and diabetes were 10.2, 8.1 and 1.4 respectively. In 2020, the number of hospital admissions due to myocardial infarction and acute ischemic stroke were 7,300 and 10,300 correspondingly[13]. From 2017 to 2019, there was an average of 3,500 to 3,700 miscarriage cases each year[14]. The current incidence rate of various diseases among vaccinated patients has not exceeded expectations. It can be considered as these diseases are not uncommon, nor are they entirely related to vaccination.
- The low level of infection in Hong Kong may cause some public to lay down their guard. Some misunderstand wearing masks and maintaining social distancing are long-lasting and feasible strategies for pandemic prevention. In fact, many countries/regions with good control over the COVID-19 disease, such as Singapore and Taiwan, have also resulted in large-scale outbreaks in recent months. Some people believed that the outbreaks in Taiwan are partly related to their low vaccination rate. Due to public hesitation towards vaccines and insufficient vaccine supply, as of May, only 2.3% (approximately 460,000 people)[15] of the population in Taiwan have received two doses of inoculation. Subsequent to the local outbreak in Taiwan, the shortage of vaccines has made it even more challenging to establish local herd immunity in a short period of time. Hong Kong citizens must learn the lesson and acknowledge that wearing masks and social distancing cannot provide adequate protection, especially when many citizens wear masks incorrectly (i.e. often pulling masks down or touching masks with fingers) and do not use alcohol sanitizers habitually. Only by getting vaccinated one can effectively protect themselves and those around.
- Many worries about vaccines' effectiveness against virus variants of concern, which are labelled as the Alpha, Beta, Gamma, Delta, and some prefer to wait for the second-generation vaccine. In fact, all the vaccines provided in Hong Kong are proven effective against the virus variants. A preliminary report from the UK found that the BioNTech vaccine was 88% effective against symptomatic disease from the Indian variant (B.1.617.2) and was 93% effective against the British variant (B.1.1.7)[16]. Clinical data in Qatar shows that people who have received two doses of the BioNTech vaccine were 75% less likely to develop a case of COVID-19 caused by the South African variant (B.1.351)[17]. As for the SinoVac vaccine, a Brazilian study found that the SinoVac vaccine was estimated at around 50% effective against symptomatic infection caused by the Brazilian variant (P.1) after completed 2 doses of vaccine[18]. It is worth noting that both vaccines can significantly reduce the severe symptoms and mortality rate of infected people. Even if breakthrough infection occurs, the vaccines can substantially reduce the risk of severe illness caused by the COVID-19 virus.
- Many people hope that after the local infection cases are "cleared", the public can gradually return to their normal life. But if Hong Kong’s vaccination uptake remains low, it is expected that control measures such as wearing masks and maintaining social distancing will persist. In terms of travelling between countries, as European countries and the US have progressively moved towards achieving herd immunity, it is foreseeable that these countries will be able to open their borders to countries that also achieve herd immunity in the future. However, in the absence of adequate immune barriers in the community, even if the Hong Kong infection cases are "cleared", quarantine requirements will not be relaxed subsequently. Tourism, international trades and other activities will continue to be suspended, and the personal freedom of citizens will remain restricted.
The COVID-19 pandemic is a protracted battle, and safe and effective vaccines are our only hope to stop the pandemic and return to normal life. The HKMA appeals to all citizens to take scientific evidence and public health into consideration, getting vaccinated as soon as possible to win this battle together!
* Total population that received at least one vaccine dose, source: https://ourworldindata.org/covid-vaccinations?country=OWID_WRL, as of 9 JUN 2021.
[10] 7 day moving average at 9 JUN 2021, source: https://coronavirus.data.gov.uk/details/cases.
[11] 7 day moving average at 9 JUN 2021, source: https://covid.cdc.gov/covid-data-tracker/#trends_dailytrendscases.
[12] Source: https://ourworldindata.org/covid-vaccinations?country=OWID_WRL, 31 MAY, 2021.
[13] Source: https://www.info.gov.hk/gia/general/202103/09/P2021030900703p.htm, 9 MAR 2021.
[14] Source: https://www.info.gov.hk/gia/general/202104/14/P2021041400576p.htm, 14 APR, 2021.
[15] Source: https://www.scmp.com/news/china/science/article/3135734/coronavirus-taiwan-step-vaccination-drive-2-million-doses-arrive, 2 JUN 2021.
[16] Source: https://www.gov.uk/government/news/vaccines-highly-effective-against-b-1-617-2-variant-after-2-doses, 22 MAY 2021.
[17] Source: https://www.nature.com/articles/d41586-021-01222-5, 6 MAY 2021.
[18] Source: https://www.nature.com/articles/s41577-021-00556-5, 10 MAY 2021.
編輯備忘：香港醫學會成立於一九二零年，旨在聯繫政府、各公立醫療機構、大學及私人執業的醫務工作者，交流意見，團結一心。醫學會致力將最新的醫療資訊及醫務發展傳遞與會員，提倡會員遵行專業操守，進而服務社會，維護民康。
Notes to editors: The Hong Kong Medical Association, founded in 1920, aims to bring together Hong Kong's government, institutional, university and private medical practitioners for an effective exchange of views and co-ordination of efforts. The foremost objective of the Association is to safeguard and promote public health. The Association speaks collectively for its members and aims to keep its members abreast of medical ethics, issues and advances around the world. In fulfilling these goals, the association hopes to better serve the people of Hong Kong.
查詢 ：袁巧蓮女士 電話 ：2527 8941
網址 ：www.hkma.org 電郵 ：media@hkma.org