Prepared by Mawlana Mateen A. Khan MD and Dr. Ramzan Judge PharmD
Summary
Permissible influenza vaccines in the US for 2024-2025 season
- FluadTM
- Fluzone High-DoseTM
- AfluriaTM
- FluarixTM
- FluLavalTM
- FluzoneTM
Impermissible influenza vaccines in the US for 2024-2025 season
- FlublokTM
- FluMistTM
- FlucelvaxTM
Discussion
Background on Influenza
Influenza (commonly known as the flu) is a seasonal viral illness that carries a significant health, economic, and social burden. The CDC estimates that between 2010 and 2023, flu has resulted in 9.3 million to 41 million illnesses, 100,000 to 710,000 hospitalizations, and 4,900 to 51,000 deaths annually. Likewise, the CDC estimates that during the 2022-2023 season, flu vaccination prevented 6.0 million flu-related illnesses, 2.9 million medical visits, 65,000 hospitalizations, and 3,700 deaths.
In addition to providing immunity to healthy individuals, the vaccine benefits the sick by decreasing their exposure to other individuals (herd immunity). Hence, the CDC and most American medical organizations recommend that every person above six months old receive a seasonal influenza vaccine yearly.[i]
Improving vaccination rates among Muslims has been a struggle. Muslim-majority countries find their populations hesitant. [ii] Similar issues are faced among Muslim minority populations in the West over a concern for the presence of impermissible ingredients in the vaccine.[iii]
The United States currently offers nine different commercially prepared vaccines.[iv] We reviewed package inserts and public records for the vaccines to evaluate their methods of production and the presence of impermissible products. When necessary, we corresponded with the manufacturers. Table 1 compiles the available vaccines, dosages, and age range.
The vaccines vary in their methods of production and ingredients, which may pose religious challenges for Muslims. Table 2 compiles the available vaccines, allergens, and permissibility. Below is a discussion of those challenges.
Challenge #1 – Methods of Production
Influenza vaccines are prepared through three different processes. Most strains are prepared through an egg-based manufacturing process. This involves injecting vaccine viruses into fertilized chicken eggs. Essentially, the egg is commandeered as a factory by the viruses as they use the egg’s resources to replicate themselves. The viruses are extracted and purified.[v] Islamically, this process per se is not an issue, as eggs are considered permissible.
Flucelvax™, a product by Seqirus, is made by incubating influenza viruses in a particular animal cell line, Madin-Darby Canine Kidney (MDCK).[vi] The MDCK cell line was initially isolated in 1958 from an adult Cocker Spaniel dog.[vii] Dogs, like all predators, are ḥarām as Sayyidunā Ibn `Abbās (May Allah be pleased with him) narrated that Allah’s Messenger ﷺ prohibited every predator possessing canine teeth.[viii] Further, when cells like MDCK are removed from an animal, they are considered maytah (carrion) in Islamic terminology. The Prophet ﷺ informed us, “Whatever is cut from an animal while it is alive is carrion.”[ix] Surah al-An`ām states a ruling of najis (impure) and ḥarām (impermissible) for carrion.
“Say, “I do not find, in what has been revealed to me, anything prohibited for anyone who eats it, unless it be carrion or blood that pours forth, or flesh of swine – because it is impure.”[x]
Hence, the initially harvested canine cells were najis and ḥarām. Since 1958, the cell line has undergone countless replication cycles in artificial environments, and the parent cells have long died off. Still, being the progeny cells, they will be impure and impermissible.
The MDCK cells used in Flucelvax™ are grown in a medium without human or animal-derived materials.[xi] After incubation, the cells are processed through lysis, and the virus proteins undergo extraction and purification. Despite this, residual amounts of the cells capable of inducing allergic reactions in susceptible patients remain, per the package insert. For these reasons, the Flucelvax™ vaccine is impermissible, particularly when other permissible alternatives exist.
FlublokTM manufactured by Sanofi, is produced by genetically engineering proteins expressed by influenza into an alternate virus, baculovirus (Autographa californica). It is then used to infect an insect cell line (ExpresSF+) derived from the fall armyworm (Spodoptera frugiperda), which produces the desired influenza proteins. This vaccine is especially valuable to those who have severe allergies to eggs. [xii] Insects, like the armyworm, fall into the category of al-khabā’ith explicitly mentioned in the Qur’an as ḥarām in Surah al-A`rāf.
[He ﷺ] makes unlawful for them impure things (al-khabā’ith).[xiii]
Like animal cell lines discussed previously, the progeny ExpresSF+ cells are impure and impermissible. Hence, FlublokTM vaccine made from this method is also impermissible particularly when other permissible alternatives exist.
Issue #2 – Porcine Gelatin as a Stabilizer
FluMistTM contains porcine gelatin.[xiv] The gelatin is added as a stabilizer for the viral vaccine protein. Gelatin is hydrolyzed collagen, which is extracted from collagen-containing tissue like skin and bones. The Qur’an declares that all porcine parts are najis and ḥarām.
Say, “I do not find, in what has been revealed to me, anything (out of the cattle under discussion) prohibited for anyone who eats it, unless it be carrion or blood that pours forth, or flesh of swine – because it is impure – or there be an animal slaughtered sinfully by invoking on it the name of someone other than Allah. (Surah al-An`ām:145)[xv]
He has but prohibited for you the carrion, the blood, the flesh of swine and what has been invoked upon with a name other than that of Allah. (Surah al-Naḥl:115)[xvi]
In earlier times, gelatin was prepared in homes through a process of cooking, causing the collagen to hydrolyze and break into peptides of varying lengths. Although the process today is commercialized and done through a series of chemical reactions, extraction, and purification, the result is not much different from home preparations. These peptides do not constitute a significant change (tabdīl al-māhiyah) from the original porcine collagen. Instead, gelatin is just fragmented hydrolyzed collagen. The resulting gelatin is impermissible.[xvii] Hence, FluMistTM is impermissible particularly when other permissible alternatives exist.
Exceptional Cases
If someone is relatively healthy and unable to take or obtain one of the permissible influenza vaccines, they should not take an impermissible vaccine. However, if a strong need exists and a permissible alternative is unobtainable, they may take normally impermissible vaccines.
As with other impermissible vaccines, practitioners and patients should employ shared clinical decision-making[xviii] to determine if the vaccine constitutes a necessity in the Sharīʻah. Shared clinical decision-making ideally involves a discussion between the patient and a pious practicing Muslim practitioner adept at assessing the patient’s clinical risk for significant mortality and morbidity while considering the dictates of the Sharīʻah.
A necessity in the Sharīʻah is when there is a high likelihood (ghalabah al-ẓann) of significant morbidity or mortality by contracting influenza, such as in the very old or patients with pre-existing significant comorbidities. Ideally, the Sharī`ah prefers a competent Muslim physician to determine this need based on the evidence at hand. The physician should be pious and have a basic understanding of the relevant Sharī`ah rulings.[xix] In the absence of such an individual, an Islamic scholar should be consulted along with the practitioner. Vaccinations mandated by the government, workplaces, or schools may also constitute a strong need.[xx]
If the parties involved agree that the patient faces a significant threat, they may take a normally impermissible vaccine to ward off that threat. This need-based permissibility is valid only until an alternative permissible vaccine becomes available. In these situations, one may take (in order of preference) FlublokTM, FlucelvaxTM, and FluMistTM.
Conclusion
Of the nine commercially available influenza vaccines available in the US for the 2023-2024 season, six are Islamically permissible: FluadTM, FluzoneTM, AfluriaTM, FluarixTM, FluLavalTM, and FluzoneTM. The Muslim public is advised to avoid FlublokTM, FluMistTM, and FlucelvaxTM.
In exceptional cases, as outlined above, one may take FlublokTM, FlucelvaxTM, and FluMistTM in order of preference.
Of note, vaccine formulations are subject to change year to year. The research presented here is accurate for the 2024-2025 season to the best of our knowledge.
Table 1: Influenza Vaccine Products for the 2024–2025 Influenza Season
| Manufacturer | Trade Name (vaccine abbreviation) | How Supplied | Age Range |
| AstraZeneca | FluMist (LAIV3) | 0.2 mL (single-use nasal spray) | 2 through 49 years |
| GSK | Fluarix (IIV3) | 0.5 mL (single-dose syringe) | 6 months & older |
| FluLaval (IIV3) | 0.5 mL (single-dose syringe) | 6 months & older | |
| Sanofi | Flublok (RIV3) | 0.5 mL (single-dose syringe) | 18 years & older |
| Fluzone (IIV3) | 0.5 mL (single-dose syringe) | 6 months & older | |
| 5.0 mL multi-dose vial (0.25 mL dose) | 6 through 35 months | ||
| 5.0 mL multi-dose vial (0.5 mL dose) | 6 months & older | ||
| Fluzone High-Dose (HD-IIV3) | 0.5 mL (single-dose syringe) | 65 years & older | |
| CSL Seqirus | Afluria (IIV3) | 5.0 mL multi-dose vial (0.25 mL dose) | 6 through 35 months |
| 5.0 mL multi-dose vial (0.5 mL dose) | 3 years & older | ||
| 0.5 mL (single-dose syringe) | 3 years & older | ||
| Fluad (aIIV3) | 0.5 mL (single-dose syringe) | 65 years & older | |
| Flucelvax (ccIIV3) | 0.5 mL (single-dose syringe) | 6 months & older | |
| 5.0 mL multi-dose vial (0.5 mL dose) | 6 months & older |
Note: All 2024–2025 seasonal influenza vaccines are trivalent. IIV = egg-based inactivated influenza vaccine (injectable); where necessary to refer to cell culture-based vaccine, the prefix “cc” is used (e.g., ccIIV); RIV = recombinant hemagglutinin influenza vaccine (injectable); aIIV = adjuvanted inactivated influenza vaccine. (adapted from immunize.org)
Table 2: 2024-2025 Influenza Vaccines
| Name | Porcine Gelatin | Culture Medium | Allergens | Manufacturer | Permissibility |
| Afluria | No | Egg | Egg protein, neomycin, polymyxin | Seqirus | Permissible |
| Fluad | No | Egg | Egg protein, neomycin, kanamycin, latex | Seqirus | Permissible |
| Fluarix | No | Egg | Egg protein | GSK | Permissible |
| Flublok | No | ExpresSF+ | None | Sanofi | Not permissible |
| Flucelvax | No | MDCK cells | None | Seqirus | Not permissible |
| FluLaval | No | Egg | Egg Protein | GSK | Permissible |
| FluMist | Yes | Egg | Egg protein | AstraZeneca | Not permissible |
| Fluzone High Dose | No | Egg | Egg protein | Sanofi | Permissible |
| Fluzone | No | Egg | Egg protein | Sanofi | Permissible |
[i] https://www.cdc.gov/flu/prevent/whoshouldvax.htm.
[ii] Ahmed, A. (2018) Outbreak of vaccine-preventable diseases in Muslim majority countries. Journal of Infection and Public Health, 11 (2), 153-155. doi.org/10.1016/j.jiph.2017.09.007
[iii] https://mcb.org.uk/mcb-updates/position-on-flu-vaccines/.
[iv] https://www.immunize.org/official-guidance/fda/pkg-inserts/?wpsolr_fq%5B0%5D=imm_vaccine_or_disease_str%3AInfluenza
[v] https://www.cdc.gov/flu/prevent/how-fluvaccine-made.htm#targetText=The%20most%20common%20way%20that,for%20more%20than%2070%20years.&targetText=For%20flu%20shots%2C%20the%20influenza,and%20virus%20antigen%20is%20purified.
[vi] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6177469/
[vii] https://en.wikipedia.org/wiki/Madin-Darby_Canine_Kidney_cells#targetText=Madin%2DDarby%20Canine%20Kidney%20(MDCK,as%20responses%20to%20growth%20factors.
[viii] عَنِ ابْنِ عَبَّاسٍ، قَالَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنْ كُلِّ ذِي نَابٍ مِنَ السِّبَاعِ (مسلم 1934)
[ix] مَا قُطِعَ مِنَ الْبَهِيمَةِ وَهِيَ حَيَّةٌ فَهِيَ مَيْتَةٌ (أبو داوود 2858، الترمذي 1480، ابن ماجه 3216)
وَعَلَى هَذَا يَخْرُجُ مَا إذَا قَطَعَ مِنْ أَلْيَةِ الشَّاةِ قِطْعَةً أَوْ مِنْ فَخِذِهَا أَنَّهُ لَا يَحِلُّ الْمُبَانُ وَإِنْ ذُبِحَتْ الشَّاةُ بَعْدَ ذَلِكَ؛ لِأَنَّ حُكْمَ الذَّكَاةِ لَمْ يَثْبُتْ فِي الْجُزْءِ الْمُبَانِ وَقْتَ الْإِبَانَةِ لِانْعِدَامِ ذَكَاةِ الشَّاةِ لِكَوْنِهَا حَيَّةً وَقْتَ الْإِبَانَةِ، وَحَالَ فَوَاتِ الْحَيَاةِ كَانَ الْجُزْءُ مُنْفَصِلًا وَحُكْمُ الذَّكَاةِ لَا يَظْهَرُ فِي الْجُزْءِ الْمُنْفَصِلِ وَرُوِيَ أَنَّ أَهْلَ الْجَاهِلِيَّةِ كَانُوا يَقْطَعُونَ قِطْعَةً مِنْ أَلْيَةِ الشَّاةِ وَمِنْ سَنَامِ الْبَعِيرِ فَيَأْكُلُونَهَا فَلَمَّا بُعِثَ النَّبِيُّ الْمُكَرَّمُ – عَلَيْهِ الصَّلَاةُ وَالسَّلَامُ – نَهَاهُمْ عَنْ ذَلِكَ فَقَالَ – عَلَيْهِ الصَّلَاةُ وَالسَّلَامُ – «مَا أُبِينَ مِنْ الْحَيِّ فَهُوَ مَيِّتٌ» وَالْجُزْءُ الْمَقْطُوعُ مُبَانٌ مِنْ حَيٍّ وَبَائِنٌ مِنْهُ فَيَكُونُ مَيِّتًا وَكَذَلِكَ إذَا قُطِعَ ذَلِكَ مِنْ صَيْدٍ لَمْ يُؤْكَلْ الْمَقْطُوعُ، وَإِنْ مَاتَ الصَّيْدُ بَعْدَ ذَلِكَ لِمَا قُلْنَا. (بدائع الصنائع في ترتيب الشرائع)
[x] قُل لَّا أَجِدُ فِي مَا أُوحِيَ إِلَيَّ مُحَرَّمًا عَلَىٰ طَاعِمٍ يَطْعَمُهُ إِلَّا أَن يَكُونَ مَيْتَةً أَوْ دَمًا مَّسْفُوحًا أَوْ لَحْمَ خِنزِيرٍ فَإِنَّهُ رِجْسٌ أَوْ فِسْقًا أُهِلَّ لِغَيْرِ اللَّـهِ بِهِ
[xi] European Medicines Agency Assessment Report on Flucelvax Tetra. 18 Oct. 2018. Pg. 14.
[xii] Barr, I. G. (2018). Cell culture-derived influenza vaccines in the severe 2017-2018 epidemic season: a step towards improved influenza vaccine effectiveness. NPJ vaccines, 3, 44. doi:10.1038/s41541-018-0079-z
See also https://www.cdc.gov/flu/prevent/egg-allergies.htm for discussion on egg allergies and influenza vaccines.
[xiii] وَيُحَرِّمُ عَلَيْهِمُ الْخَبَائِثَ
(وَأَمَّا) الَّذِي يَعِيشُ فِي الْبَرِّ فَأَنْوَاعٌ ثَلَاثَةٌ: مَا لَيْسَ لَهُ دَمٌ أَصْلًا، وَمَا لَيْسَ لَهُ دَمٌ سَائِلٌ، وَمَا لَهُ دَمٌ سَائِلٌ مِثْلُ الْجَرَادِ وَالزُّنْبُورِ وَالذُّبَابِ وَالْعَنْكَبُوتِ وَالْعَضَّابَةِ وَالْخُنْفُسَاءِ وَالْبُغَاثَةِ وَالْعَقْرَبِ.
وَنَحْوِهَا لَا يَحِلُّ أَكْلُهُ إلَّا الْجَرَادَ خَاصَّةً؛ لِأَنَّهَا مِنْ الْخَبَائِثِ لِاسْتِبْعَادِ الطِّبَاعِ السَّلِيمَةِ إيَّاهَا وَقَدْ قَالَ اللَّهُ تَبَارَكَ وَتَعَالَى {وَيُحَرِّمُ عَلَيْهِمُ الْخَبَائِثَ} [الأعراف: 157] إلَّا أَنَّ الْجَرَادَ خُصَّ مِنْ هَذِهِ الْجُمْلَةِ بِقَوْلِهِ – عَلَيْهِ الصَّلَاةُ وَالسَّلَامُ – «أُحِلَّتْ لَنَا مَيْتَتَانِ» فَبَقِيَ عَلَى ظَاهِرِ الْعُمُومِ. وَكَذَلِكَ مَا لَيْسَ لَهُ دَمٌ سَائِلٌ مِثْلُ الْحَيَّةِ وَالْوَزَغِ وَسَامِّ أَبْرَصَ وَجَمِيعِ الْحَشَرَاتِ وَهَوَامِّ الْأَرْضِ مِنْ الْفَأْرِ وَالْقُرَادِ وَالْقَنَافِذِ وَالضَّبِّ وَالْيَرْبُوعِ وَابْنِ عِرْسٍ وَنَحْوِهَا، وَلَا خِلَافَ فِي حُرْمَةِ هَذِهِ الْأَشْيَاءِ إلَّا فِي الضَّبِّ (بدائع الصنائع في ترتيب الشرائع)
[xiv] Seqirus, Medical Information Specialist, personal communication, October 14, 2019.
[xv] قُل لَّا أَجِدُ فِي مَا أُوحِيَ إِلَيَّ مُحَرَّمًا عَلَىٰ طَاعِمٍ يَطْعَمُهُ إِلَّا أَن يَكُونَ مَيْتَةً أَوْ دَمًا مَّسْفُوحًا أَوْ لَحْمَ خِنزِيرٍ فَإِنَّهُ رِجْسٌ أَوْ فِسْقًا أُهِلَّ لِغَيْرِ اللَّـهِ بِهِ
[xvi] إِنَّمَا حَرَّمَ عَلَيْكُمُ الْمَيْتَةَ وَالدَّمَ وَلَحْمَ الْخِنزِيرِ وَمَا أُهِلَّ لِغَيْرِ اللَّـهِ بِهِ
[xvii] Respectfully, the minority opinion considering gelatin to have undergone a significant transformation (tabdīl al-mahiyah) rendering its ruling changed seems doubtful for the reasons outlined. This is an extensive discussion. However, with the availability of clearly ḥalāl alternatives, the opinion given in this article is more cautious and avoids disagreement.
[xviii] https://www.cdc.gov/vaccines/acip/acip-scdm-faqs.html#scdm
[xix] وَجَوَّزَهُ فِي النِّهَايَةِ بِمُحَرَّمٍ إذَا أَخْبَرَهُ طَبِيبٌ مُسْلِمٌ أَنَّ فِيهِ شِفَاءً وَلَمْ يَجِدْ مُبَاحًا يَقُومُ مَقَامَهُ. قُلْت: وَفِي الْبَزَّازِيَّةِ وَمَعْنَى قَوْلِهِ – عَلَيْهِ الصَّلَاةُ وَالسَّلَامُ – «إنَّ اللَّهَ لَمْ يَجْعَلْ شِفَاءَكُمْ فِيمَا حُرِّمَ عَلَيْكُمْ» نَفْيُ الْحُرْمَةِ عِنْدَ الْعِلْمِ بِالشِّفَاءِ دَلَّ عَلَيْهِ جَوَازُ شُرْبِهِ لِإِزَالَةِ الْعَطَشِ (رد المحتار على الدر المختار)
[xx] Imdād al-Fatāwa Jadīd maʻa Hāshiyah Shabbīr Aḥmad al-Qāsimī, 9:262
muslimmed.org 