目前新冠肺炎疫苗在全球的施打已經超過一億劑，我們期待新冠肺炎病毒感染的速率持續的緩和，能讓世界各地的生活盡快恢復正常，然而國外也陸續傳來施打疫苗後產生不良反應的案例，針對接種疫苗的利弊風險，各國的政府和專案也開始有許多討論。
在台灣，AZ疫苗已經開打幾週了，在這段期間有很多病人問我能不能去接種AZ 疫苗，我想從一位婦產科醫師的角度出發，跟大家分享自己的觀點，讓大家在跟醫師們討論需不需要接種時，能先有初步的觀念。
AZ疫苗可能造成的不良反應
目前國際上接種AZ 疫苗後出現嚴重不良反應的案例有兩種最受矚目：一種是嚴重的過敏反應；另外一種則是凝血過多或不足的反應。
這兩種不良反應的發生率都小於10萬分之一，很難在疫苗臨床試驗階段被發掘出來，因此只能在疫苗流通到市場後，依靠健全的通報系統蒐集更完整的數據，才有機會分析疫苗與不良反應之間的關聯。
以嚴重過敏反應來說，任何疫苗都可能因為載體的關係產生嚴重的過敏反應，所以病人在施打疫苗過後的30分鐘內，一定要留在施打的醫療院所接受觀察。AZ疫苗中使用的為Polysorbate80 或類似的分子，如果你之前曾經因為接種疫苗而有過敏反應，應該要在接種前詢問醫師AZ疫苗的載體與該次引起過敏的疫苗載體是否相同，以利避免風險。
另外一種不良反應與與血液相關，這一點比較受爭議。在2500多萬個施打的個案中，出現86 個血液異常的不良反應，大部份的這些個案都是女性而且發生在施打的頭2個禮拜。德國、法國和義大利等20幾個國家因此一度暫停施打AZ疫苗，雖然機率不大，但誰都不想冒這個險。但有些歐洲國家和澳洲最近又恢復施打，但建議50歲以下接種其他疫苗 (也有國家說30歲以下) 原因是不同專家對於這些異常凝血的不良反應與AZ疫苗的相關性有不同的見解。
婦女接種AZ疫苗前宜停看聽
對於目前正在服用避孕藥或女性荷爾蒙的女性來說，施打AZ疫苗會不會增加血栓的風險呢? 坦白說，目前資訊還不是非常完整，所以我暫時無法評論，但後續會密切注意最新的研究報告，有進一步消息，會再跟大家分享。
對於目前正在備孕，或是即將成為準媽媽的女性來說，更是需要持續追蹤這款疫苗的不良反應，因為如果病患在懷孕期間不幸感染新冠肺炎，因此發生嚴重呼吸道疾病的機率高達未孕女性的3倍，而且因為媽媽發燒或肺炎病毒造成胎兒發育不良的機率也大幅增高。相對的，在AZ臨床試驗中施打疫苗後發現懷孕的女性約有一萬人，正接受持續的密切追蹤，截至目前為止尚無證據顯示AZ疫苗會對母親或胎兒健康造成嚴重影響。這些案例和研究資訊告訴我們，女性朋友們在施打這個疫苗前更需要審慎的個別的情況，才能跟醫師有充份的溝通和討論。
誰該接種AZ疫苗?誰需要小心?
那麼在實務上究竟應不應該建議接種AZ疫苗呢?我認為決定的因素有幾個:
病人接觸新冠肺炎的風險
台灣目前沒有社區感染，感染病毒的機會並不高，只是境外移入仍存在風險，短期來說，若是爆發社區感染才開始接種疫苗，也需要等三個禮拜以上才能形成有效地保護力。而長遠來說，國人還是需要接種疫苗達到一定比率才能安全的開放國門。若是因為工作需要出國的朋友，就應該依目的地的盛行率做決定，像是在歐美地區，接種疫苗的好處明顯的大於壞處；而像我一樣的醫護人員，在工作上比較有可能接觸到病毒帶原者，感染的風險也會較高，也應該考慮接種疫苗，增加保護力。
病人是否罹患慢性病
研究顯示有高血壓、糖尿病或BMI >30的病患在感染新冠肺炎病毒後，更容易而產生嚴重的呼吸道疾病，因為健康上的風險高，上述慢性病的病患也可以考慮接種疫苗。若有上述問題但懷孕的婦女，則應與婦產科醫師討論其利弊。
備孕或懷孕中的婦女
接種AZ疫苗後，有超過半數的人反應接種處疼痛、倦怠或頭痛的問題，而且大約有1成的人會發燒，雖然這些不良反應都是暫時的，很快就會消失，若希望盡可能避免懷孕初期發燒的情況，計劃懷孕或孕期中的女性可以考慮懷孕初期避開接種疫苗。有些證據顯示若接種第一劑後懷孕，在生產後才接種第二劑也能提供相同的保護，不需再重打第一劑。若孕期間接種其他疫苗如百日咳與流感疫苗則與AZ疫苗的施打需考慮間隔約兩個禮拜。
接種AZ疫苗有利有弊，除了關切衛福部及相關專家提出的建議，我們也可以就自己目前的狀態先想一想，在做決定前停看聽，如果有其他的問題，千萬別忘了跟你的醫師作討論喔！
The global “COVID-vaccinated” population has reached 100 million. In the process of reaching herd immunity via mass vaccination, more rare but serious adverse effects from these vaccines are being reported in the mass media. Discussions about the safety of vaccines arevigorous at both government and the community levels.
The AstraZeneca (AZ) vaccine has been used for COVID vaccination in Taiwan for a few weeks now. Many of my patients asked me if they are suitable for vaccination. So here I would like to share my thoughts with you as an obstetrician and gynaecologist.
Adverse reactions associated with the AZ vaccine
There are two types of adverse reactions being discussed the most in the international community: severe allergic reactions and blood-clotting problems. Both of these adverse reactions occur in the order of one in ten thousand, which were difficult to discover during the clinical trial stage. Therefore most of the data we see now are an accumulation of real-time data as we proceed with global vaccination.
The severe allergic reaction (such as anaphylaxis) can occur with any medication being administered to the human body. For vaccines it is usually the vehicle or the excipients molecule with which it is used to carry the active vaccine that incites the allergic reactions. Polysorbate 80 is a suspected culprit excipient used in the AZ vaccine. So if one has had severe allergic reaction in other vaccines that uses polysorbate 80 as its vehicles then it is possible the person can also be allergic to the AZ vaccine.
The abnormal blood-clotting reactions associated with the AZ vaccines are being discussed vigorously in both the scientific community and the media. In about 25 million recipients of the AZ vaccine, 86 cases of serious abnormal blood-clotting cases were reported by March 2021. Most cases occur within first 2 weeks of vaccination and most are women. Although the AZ vaccination was temporarily stopped in some European countries earlier in March, it has resumed since with some countries recommend vaccination in those 50 yo or above (some say 30 or above). Currently there is no international consensus amongst the experts.
Many professional bodies of obstetrics and gynaecology around the world have issued statements regarding vaccination against COVID19 in women planning pregnancy or breast feeding. Thus far most have only cautioned against the vaccination if there is serious concurrent comorbidities such as those who are immunocompromised or organ transplant. There does not seem to have report of additional risks of the vaccination during pregnancy. There is insufficient evidence to conclude if oral contraceptives and hormone replacement therapy are risk factors for developing vaccine-related blood clotting events. More time and data are required to tell.
So should women receive the AZ vaccine? These factors should be considered and discussed with your doctors.
Risk of contracting COVID
Contracting COVID during pregnancy is associated with 3-fold risk of serious complications. So immunisation against COVID should be prioritised if the area you live in carries high risk of infection.
Underlying chronic conditions
For those with hypertension, diabetes or high BMI, because higher risk of COVID related complications are expected, vaccination might offer risk-reducing benefits. but in women with diabetes or high BMI where high risk pregnancy is expected, one should discuss the risks and benefits with your own obstetrician.
Pregnancy
More than half of recipients will get injection site pain and about 10% will develop a fever. To avoid fever during early pregnancy one can avoid getting vaccination during this period. If one has become pregnant after the first dose, there is evidence that receiving a second dose after pregnancy still offers protection against COVID. for those who need flu or whooping cough vaccination during pregnancy, one should consider taking the COVID vaccine 2 weeks apart from the other vaccines.
Like all medicines/procedures, decision to receive the AZ vaccination is individualised based on the benefits and risks associated. It is important to review government updates on vaccination and this article hopefully provides some framework on which women can consult their physicians when considering the AZ vaccination.
