The data says no. Specifically in Spain, cases of adverse reactions to coronavirus vaccines have been very low, and in no case serious.
This is clear from the first Pharmacovigilance Report on Covid-19 vaccines, published on January 25 by the Spanish Agency for Medicines and Health Products (AEMPS) . As of January 12, 494,799 people had been vaccinated in Spain and 374 notifications of adverse events had been received. The most frequent were those related to general disorders (fever, malaise), central nervous system (headache, dizziness) and digestive system (nausea, diarrhea).
The AEMPS explained that the 374 notifications included 831 descriptive terms of adverse events, ” since the same case may contain several terms, for example, a person may have had pain at the injection site and fever after administration of the vaccine .”
According to the Vaccination Registry of the Ministry of Health, 70% of those vaccinated have been women. And regarding the distribution by age groups, 62% of those immunized are between 18 and 64 years old and 38% are older than 65 years.
Eleven cases per million
From the point of view of allergic-type reactions, a recent review by the Center for Disease Control and Prevention in the United States estimates an anaphylaxis rate of 11.1 cases per million administered doses, based on the notifications received that meet the definition of established anaphylaxis ( Brighton Collaboration ). In Spain, during the period analyzed in this report, four cases that meet these criteria for anaphylaxis have been identified. All of them occurred in women who recovered or were in recovery after receiving the corresponding treatment. In three of the cases there was a personal history of an allergic reaction.
The British authorities have initially attributed the cause of the allergic reactions to an excipient in the COVID vaccine, polyethylene glycol.
At the moment we only have experience with the Pfizer vaccine, which is made up of RNA from the virus carried in lipid nanoparticles of polyethylene glycol or macrogol. This vaccine does not contain traces of eggs or antibiotics (such as MMR or flu). Reactions to this substance, according to the Spanish Society of Allergy and Clinical Immunology (SEAIC), are extremely rare.
Anaphylactic reactions to macrogol and cross reactivity to Tween80 / polysorbate 80 have been described. Within the rare occurrence of allergy to this substance, some contact dermatitis pictures have been described that fortunately do not involve serious reactions.
In the Allergy consultation at our Río Hortega University Hospital in Valladolid, we have prepared excipients similar to those contained in the Pfizer vaccine. Specifically, we have tested Moviprep, which is normally used to prepare the intestine prior to a colonoscopy, and which contains macrogol.
And what about the vaccines that come?
Moderna’s vaccine contains trometamol, also present in the ampoules, of an anti-inflammatory called Ketorolac, a derivative of acetic acid. We consider it advisable to warn patients sensitive to this group of non-steroidal anti-inflammatory analgesics (NSAIDs) that they are going to be vaccinated with Moderna.
However, it seems that reactions to vaccination against COVID-19 are anecdotal, lower than those observed with penicillins, 0.002%. Pfizer’s vaccine has caused reactions in 11.1 cases per million administered doses, or 0.001%. Vaccination is not even contraindicated in people with allergies to food, drugs, animals, insects, allergens in the environment, or latex.
Vaccinations once the disease is over
One factor to take into account is the possible increase in adverse reactions when vaccinating a person who has previously suffered from COVID-19. If there is an excess of antibodies, that is, those generated to the virus by infection plus those generated by vaccination, a type III hypersensitivity reaction may develop.
In type III hypersensitivity, soluble immune complexes are formed in the blood, that is, aggregates of IgG and IgM antibodies, which are deposited in various tissues (skin, blood vessels, kidney, joints, etc.). Once deposited, they trigger an immune response based on the classical pathway of complement activation and can cause vasculitis, glomerulonephritis, and arthritis.
Why? When IgG and IgM antibodies bind to the viral antigen, the antigen-antibody complexes become larger and difficult to eliminate, so they end up scattered and deposited in the aforementioned tissues. The reaction can take from several hours to days to develop.
Possibly in this sense have been the recent recommendations to delay vaccination in patients who have already suffered from COVID.
Alicia Armentia Medina, Professor of Allergy. Department of Medicine. Head of the Allergy Department of the Río Hortega University Hospital, University of Valladolid
This article was originally published on The Conversation. Read the original.
