Praise be to Allah.
There is nothing wrong with receiving the Covid-19 vaccine during the day in Ramadan, because it comes under the heading of medical injections that do not break the fast, because they are not regarded as food or drink, and they do not enter the body through the usual routes for eating and drinking, namely the mouth and nose.
It says in a statement of the Islamic Fiqh Council which was issued during its tenth conference in Jeddah in the Kingdom of Saudi Arabia, 23-28 Safar 1418 AH/28 June-3 July 1997 CE:
After reviewing the papers submitted to the Council on the topic of things that break the fast in the field of medical treatment, and the studies, papers and recommendations issued by the Ninth Medical Fiqh Symposium that was held by the Islamic Medical Organization, in cooperation with the Council and other bodies, in Casablanca in the Kingdom of Morocco, 9-12 Safar 1418/14-17 June 1997 CE, and after listening to the discussions that took place around this topic with the participation of fuqaha’ and doctors, and after examining evidence from the Qur’an and Sunnah, and the words of the fuqaha’, the following was determined:
1.. The following matters are not regarded as breaking the fast:
… 8.. Subcutaneous, intramuscular or intravenous injections, with the exception of liquids and injection of nutrients.
End quote from Majallat Majma ‘ al-Fiqh al-Islami, issue no. 10.
It says in Fataawa al-Lajnah ad-Daa’imah li’l-Ifta’ (10/252): It is permissible to receive medicine by injection into a muscle or vein, for one who is fasting, during the day in Ramadan. But it is not permissible for one who is fasting to receive an injection of nutrients during the day in Ramadan, because that comes under the same ruling as consuming food and drink, so using such injections is regarded as a trick to break the fast in Ramadan. If it is possible to give the intramuscular or intravenous injection during the night, that is better. End quote.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: The scholars include under the heading of that which breaks the fast anything that is akin to food and drink, such as injection of nutrients. Injections that energize the body or heal it are not regarded as nutrients; rather injection of nutrients means that which takes a place of food and drink.
Based on that, any injection that does not take the place of food and drink does not break the fast, whether it is injected into a vein, or into the thigh, or into any other place.
End quote from Majmoo‘ Fataawa wa Rasaa’il al-‘Uthaymeen (19/199).
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him) was asked:
Do vaccinations affect the fast?
They do not affect it, and the fast is valid. Injections for vaccinations or for medical treatment do not affect the fast, according to the correct view, except for injections of nutrients. This is what affects the fast. As for regular injections, for vaccinations and so on, the correct view is that they do not affect the fast, and the fast is valid.
Host: May Allah reward you with good. Does that apply whether it is intramuscular or intravenous?
Shaykh: Yes. This is the correct view.
End quote from the website of Shaykh Ibn Baaz.
Shaykh Dr. Sa‘d al-Khathlaan (may Allah preserve him) said:
If someone receives a Covid-19 vaccine during the day in Ramadan, does that break his fast?
Answer: It does not break his fast, because the Covid-19 vaccine comes under the heading of injections for medical purposes, and injections for medical purposes do not break the fast, according to the correct view. That is because they are not food or drink, and do not come under the same heading as food and drink. The basic principle is that the fast is valid, and we cannot turn away from this basic principle and say that the fast is broken unless there is some clear proof.
Based on that, we say that there is nothing wrong with the fasting person receiving the Covid-19 vaccine, and it does not break the fast.
And Allah knows best.