早期檢測表明新冠疫苗加強針對抗奧密克戎效果良好

美國製藥商莫德納公司週一表示，其新冠疫苗的第三針可以預防奧密克戎版本的新冠病毒。

莫德納公司表示，實驗室檢測表明，其半劑量的加強針將能夠對抗奧密克戎的抗體水平提高了37倍。全劑量加強針的效果甚至更強。該公司稱其能提供83倍的抗體水平。大多數莫德納加強針都使用半劑量注射。但是對於免疫系統較弱人群，建議注射全劑量的第三針。

莫德納的早期結果尚未經過其他科學家的仔細研究。但是美國國立衛生研究院的檢測發現抗體水平出現了類似增長。

另一家美國公司輝瑞製藥表示，檢測發現其新冠疫苗導致對抗奧密克戎的抗體大幅增加。輝瑞及其德國合作伙伴生物新科技公司本月表示，早期實驗室檢測表明，其全劑量加強針將抗體水平提高了25倍。

輝瑞和莫德納公司生產的疫苗都採用了信使核糖核酸技術。這種疫苗被全球許多國家用來抗擊這次大流行。衛生官員建議人們儘快注射加強針。

抗體水平可以預測疫苗預防新冠病毒感染的效果。然而，它們只是免疫系統防禦的一部分。其它研究表明，疫苗應該對重症提供良好的保護。即使完全接種疫苗人士感染了所謂的突破性感染，情況也應該如此。

莫德納和輝瑞公司都在開發疫苗以便在需要時更好地應對奧密克戎變種。輝瑞公司最近還表示，其治療新冠肺炎的實驗性藥丸似乎對奧密克戎變種效果很好。

奧密克戎最初於11月9日在非洲南部發現，並於11月24日向世衛組織報告。兩天之後，世衛組織將其定為關切變種。

20 December 2021

American drugmaker Moderna said Monday that a third dose of its COVID-19 vaccine should protect against the Omicron version of the new coronavirus.

Moderna said laboratory tests showed its half-dose booster shot increased the level of antibodies able to fight Omicron by 37 times. A full-dose booster had an even stronger effect. The company said it gave 83 times the antibody levels. Half-dose shots are being used for most Moderna boosters. But a full-dose third shot has been advised for people with weakened immune systems.

Moderna's early results have not yet been carefully examined by other scientists. But testing by the U.S. National Institutes of Health found a similar increase in antibody levels.

Another American company, Pfizer, said testing found its COVID-19 vaccine led to a big increase in Omicron-fighting antibodies. Pfizer and its German partner BioNTech said this month that early lab tests showed its full-strength booster increased levels of antibodies by "25-fold."

The vaccines made by Pfizer and by Moderna are both made with messenger RNA technology. The shots are used by many countries around the world to fight the pandemic. Health officials are advising people to get booster injections as soon as possible.

Antibody levels predict how well a vaccine may prevent infection with the coronavirus. However, they are just one part of the immune system's defenses. Other research suggests the vaccine should offer good protection against severe disease. This should be the case even if a fully vaccinated person gets what is known as a breakthrough infection.

Both Moderna and Pfizer are developing shots to better deal with the Omicron variant in case they are needed. Pfizer also recently said its experimental pill to treat COVID-19 appears to work well against the Omicron version.

Omicron was first found in southern Africa on November 9 and reported to the World Health Organization (WHO) on November 24. Two days later, the WHO designated it a variant of concern.