Permissible and Impermissible Antigens
Purification of Permissible Antigens Mixed with Impure Solutions

Prepared by MuslimMed Team

As we routinely comment on vaccine ingredients, we thought it necessary to outline the Sharʻī position on vaccine antigens. Additionally, the same principles apply to other consumables like food. This policy statement will serve as a reference point in future fatāwā.

The permissibility of vaccine antigens is dependent on their source. If the antigen is derived or taken from bacteria, which are permissible (ḥalāl) by their nature, the antigen likewise will be permissible. If the antigen is derived from an impermissible (ḥarām) source, e.g., propagated monkey cells, the antigen will likewise be impermissible. At times, we find during antigen sourcing that the antigens may be placed into an impure (najis) solution. For example, antigen-containing bacteria are lysed open, causing the antigens to mix in an impure medium, e.g., animal-derived ingredients.

At this point, we view the antigen as a pure solid placed into an impure liquid. In this state, the antigen requires cleansing from the impure solution to render it pure. Several purification and concentrating techniques are employed by industry to achieve isolation of the antigen. The FDA oversees the level of antigen purity at the time of initial approval of manufacturing and subsequently in batch testing. Each of the techniques involves varying levels of washing:

1. Chromatography makes use of differing characteristics of solutes in a common solution to separate them from one another. Although various types of chromatography exist, column chromatography is most often utilized in vaccine antigen isolation. In this type, the antigen-containing solution is placed over the solid phase. The liquid phase drives the solution through as its components separate out in the solid phase. The liquid phase is a chemical solution that serves the purpose of both separating the antigen from other components in the impure solution and washing the antigen.[i]
2. Diafiltration is a process by which the desired antigen is concentrated while simultaneously washing out unwanted components. A pure filtrate is continuously passed through the concentrate over a semipermeable membrane. This serves to transfer unwanted components, including water molecules through the membrane while retaining and washing the desired antigen.[ii]
3. Protein precipitation and solvent extraction involve using salts or detergents to precipitate proteins from solution and then further separation by centrifugation. The salts or detergents are then extracted by washing with pure solvents, which also renders the antigen pure.
4. Ammonium sulfate precipitation involves achieving an appropriate ammonium sulfate concentration that forces the desired antigen or protein to precipitate from the solution. The precipitate is then collected by centrifugation and washed with a buffer solution until the ammonium sulfate is removed from it. This last step serves to render the antigen pure.[iii]

Considering that purification steps are on the micro scale and remove contaminants from solutions by many magnitudes of tens and that purification steps employ one or more of the above washing techniques, the resultant antigen is considered pure (ṭāhir) and fit for consumption and/ or injection. Theoretically, some impure contaminants may remain on the extreme micro scale, but the Sharīʻah overlooks such unwanted contamination and considers its removal as undue hardship.[iv]

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[i] Coskun O. Separation techniques: Chromatography. North Clin Istanb. 2016 Nov 11;3(2):156-160. doi: 10.14744/nci.2016.32757. PMID: 28058406; PMCID: PMC5206469.

[ii] Diafiltration: A fast, efficient method for desalting, or buffer exchange of biological samples, by Pall Life Sciences, PN 33289

[iii] Wingfield, P. (1998). Protein Precipitation Using Ammonium Sulfate. Current Protocols in Protein Science, A.3F.1–A.3F.8. doi:10.1002/0471140864.psa03fs13 

Grodzki AC, Berenstein E. Antibody purification: ammonium sulfate fractionation or gel filtration. Methods Mol Biol. 2010;588:15-26. doi: 10.1007/978-1-59745-324-0_3. PMID: 20012814.

[iv] حاشية ابن عابدين، محمد أمين ابن عابدين، دار السلام، 2023م، 2:396-406

(و) يطهر محل (غيرها) أي: غير مرئية (بغلبة ظن غاسل) لو مكلفا وإلا فمستعمل (طهارة محلها) بلا عدد به يفتى. (وقدر) ذلك لموسوس (بغسل وعصر ثلاثا)

أقول: وهو خلاف ما في الكافي مما يقتضي أنهما قول واحد، وعليه مشى في شرح المنية فقال: فعلم بهذا أن المذهب اعتبار غلبة الظن وأنها مقدرة بالثلاث لحصولها به في الغالب وقطعا للوسوسة وأنه من إقامة السبب الظاهر مقام المسبب الذي في الاطلاع على حقيقته عسر كالسفر مقام المشقة اهـ.

أما لو غسل في غدير أو صب عليه ماء كثير، أو جرى عليه الماء طهر مطلقا بلا شرط عصر وتجفيف وتكرار غمس هو المختار.

(قوله: أو صب عليه ماء كثير) أي: بحيث يخرج الماء ويخلفه غيره ثلاثا؛ لأن الجريان بمنزلة التكرار والعصر هو الصحيح سراج.

مراقي الفلاح شرح متن نور الإيضاح، حسن بن عمار بن علي الشرنبلالي، المكتبة العصرية (الشاملة)، 67

ولا يضر بقاء أثر شق زواله وغير المرئية بغسلها ثلاثا

“ولا يضر بقاء أثر” كلون أو ريح في محلها “شق زواله”.

والمشقة أن يحتاج في إزالته لغير الماء أو غير المائع كحوض وصابون لأن الآلة المعدة للتطهير الماء فالثوب المصبوغ بمتنجس يطهر إذا صار الماء صافيا مع بقاء اللون وقيل يغسل بعده ثلاثا ولا يضر أثر دهن متنجس على الأصح بزوال النجاسة المجاورة