[REVIEW] : Vaccine. Is receiving an injection in the buttocks less effective than in the shoulder?

Since the start of the epidemic, millions of French people have been vaccinated. And in the vast majority of cases, the vaccine was injected into the shoulder. This is the area recommended for injection. Quite simply because the vaccine must be injected into the muscle. But we have muscles in the buttocks, would the efficiency be the same?

Vaccine: Injection into the deltoid remains the most effective

In its user guide, Pfizer is very clear about this. Do not “inject this vaccine intravascularly (into the blood vessels), subcutaneously (into the fat mouth directly under the skin) or intradermally (into the dermis)”. It is indeed the muscle and simply the muscle that we must aim for with a needle that will penetrate deeply. And the leaflet recommends a muscle in particular: “ Intramuscularly into the deltoid muscle after dilution ».

The muscles are indeed valuable allies, they who optimize the immune response desired by the vaccine. Indeed, muscles release molecules called moykines, which boost our immune defenses. This is why to avoid getting sick, it is advisable to do at least twenty minutes of exercise a day.

At the time of vaccination, the muscles activate a number of mechanisms that simply allow the production of antibodies. Dr René Najeta, epidemiologist and editor of the vaccine education site History of vaccines, talked about it in more detail last March on the BBC: “In the muscle, there is a lot of vascularization, a lot of blood, and that means that there is a greater presence of immune cells. These cells are the ones that can pick up the vaccine, whether it’s messenger RNA in the case of the Moderna or Pfizer vaccines or DNA through adenovirus, in the case of Johnson and Johnson, and bring it to the cell where it is needed. »

What about the injection in the buttocks?

If the muscles are targeted, we can think of the buttocks. After all, we all (more or less) have muscles in this part of the body. Moreover, the Ministry of the Interior leaves the door open: ” Vaccination consists of an intramuscular injection, usually in the shoulder “, he says. If you feel like it, can you ask a nursing staff to give you the injection in your buttocks? Not sure !

Dr. René Najeta explains why: “In adults, the buttocks could also be an option, but this is not practical because they sometimes contain fatty tissue, what makes the vaccine less effective “. If you’re used to squats and lunges at the gym and your body fat is low, why not. Otherwise, you’ll have to settle for the shoulder for your dose. But what if the vaccine is injected into fat and not directly into muscle? ” Antigen may also take longer to reach the circulation after being deposited in fat, resulting in an r****d in immune response processing. ».

The mandatory booster dose to keep the health pass

The government announced it. Faced with the immune response that decreases over the months, a booster dose is mandatory so that the health pass is still valid. This is a third dose for those who have never had covid before their first dose. In addition, we will soon no longer be talking about a health pass but about a vaccination pass. In other words, a negative test is no longer enough. It will be necessary to prove that you have received all the doses of vaccine requested.

The government makes these decisions in the face of the increase in the number of cases with two variants very present in the territory: Delta, which has been wreaking havoc for a few months, and Omicron which is spreading rapidly in France. On the other hand, and contrary to rumours, a curfew will not be put in place on the evening of December 31. Emmanuel Macron is counting on the French to do this booster dose, and hopes that those who have not yet decided to be vaccinated will take the plunge. All hopes in the end of the crisis are indeed placed in the vaccine, while laboratories are still actively working to find an effective treatment that would avoid hospitalization.

Vaccine. Is receiving an injection in the buttocks less effective than in the shoulder?

Vaccines against Covid-19 must be injected into muscles. This is why those of the upper arm are preferred during the injection. The buttocks are also equipped with muscles. So why is vaccination in the buttocks rare?

“I wanted to know if the fact of having received my three doses in the gluteal muscle diminished or canceled the vaccine protection? » This is the question asked by Anne, from Tours (37).

This question might make you smile at first. Few people have been vaccinated elsewhere than on the shoulder. But this question deserves attention. Can the injection of anti-Covid vaccines be done elsewhere than in the shoulder? If so, is it as effective? We answer you.

The deltoid, simple, effective

Depending on their nature, vaccines can be administered in different areas. Shoulder, belly, thighs, buttocks most often. Regarding vaccination against the new coronavirus, vaccine manufacturers and health authorities, however, recommend an intramuscular injection. The deltoid muscle, one of the muscles of the shoulder, is the one that is advocated.

Pfizer clearly states this in its IFU: do not inject this vaccine intravascularly (into the blood vessels), subcutaneously (into the layer of fat directly under the skin) or intradermally (into the dermis)”. The lab explains that you have to target the muscle with a needle that penetrates deeply: “Intramuscularly into the deltoid muscle after dilution”, is it written on the record.

Asked about the subject, Dr. René Nájera, epidemiologist and editor of the educational site on vaccines History of vaccines, from the Philadelphia College of Physicians, explained last March to the BBC that“with vaccines like those against Covid-19, we look for the abundant presence of tissues, or muscles, to allow the subsequent activation of antibodies against the disease”.

The advantage? “In the muscle, there is a lot of vascularization, a lot of blood, and that means that there is a greater presence of immune cells, argues the scientist. These cells are the ones that can pick up the vaccine, whether it’s messenger RNA in the case of the Moderna or Pfizer vaccines or DNA through adenovirus, in the case of Johnson and Johnson, and bring it to the cell where it is needed. »

Covid-19: after Christmas, a dive in the number of positive cases in 24 hours

Against the 104,611 new cases of Covid-19 detected in France in 24 hours on December 25, just over 27,000 new cases were recorded on Sunday December 26. An artificial drop linked to the holiday. The epidemic continues to spread and a defense council is scheduled for Monday, December 27 to decide on new measures. Relive the news from Sunday, December 26 on the coronavirus pandemic.

An artificial drop in the number of contaminations in France. Whereas l he France crossed on Saturday December 25, 2021, Christmas Day, the bar of 100,000 new cases of Covid-19 in 24 hours, the number of cases recorded this Sunday is 27,697. An artificial drop which is explained by the day holiday.

New measures expected. Emmanuel Macron will meet, Monday, December 27, at 4 p.m., a health defense council before an extraordinary council of ministers. Objective: to decide on new measures to stem the Omicron surge.

Caregivers ask to postpone the start of the school year. In an open letter, fifty health personnel asked Olivier Véran on Sunday, December 26, for measures to curb the epidemic at school, including the postponement of the start of the school year. They are worried about the consequences of the epidemic on the health of the youngest and call for the vaccination of children.

Hot