After the approving of Pfizer-BioNTech and Moderna COVID-19 vaccines the Advisory Committee on Immunization Practices (ACIP) has issued vaccines interim clinical considerations for the prevention of coronavirus disease 2019 (COVID-19) in the United States.
“Both vaccines are lipid nanoparticle-formulated, nucleoside-modified mRNA vaccines encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19,” – Centers for Disease Control and Prevention (CDC) writes, “Either of the currently authorized mRNA COVID-19 vaccines can be used when indicated; ACIP does not state a product preference.
However, these mRNA COVID-19 vaccines are not interchangeable with each other or with other COVID-19 vaccine products. The safety and efficacy of a mixed-product series have not been evaluated. Both doses of the series should be completed with the same product. However, if two doses of different mRNA COVID-19 vaccine products are inadvertently administered, no additional doses of either product are recommended at this time.”
Contraindications And Precautions
Contraindications can be severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine is a contraindication to vaccination for both the Pfizer, and Moderna COVID-19 vaccines.
“Anaphylactic reactions in persons who received Pfizer COVID-19 vaccine outside of clinical trials have been reported. While these reports are further investigated, CDC considers a history of severe allergic reaction (e.g., anaphylaxis) to any other vaccine or injectable therapy (e.g., intramuscular, intravenous, or subcutaneous) as a precaution but not a contraindication to vaccination for both the Pfizer and Moderna COVID-19 vaccines (as these vaccines contain ingredients in common). These persons may still receive mRNA COVID-19 vaccination, but they should be counseled about the unknown risks of developing a severe allergic reaction and balance these risks against the benefits of vaccination,” – was reported in the article.
For those determined to have had a severe allergic reaction to another vaccine or injectable medication, considerations for the administration of an mRNA COVID-19 vaccine might include:
- Risk of exposure to SARS-CoV-2 (e.g., because of residence in a congregate setting such as a long-term care facility, occupation)
- Risk of severe disease or death due to COVID-19 (e.g., because of age, underlying medical conditions)
- The unknown risk of anaphylaxis (including fatal anaphylaxis) following mRNA COVID-19 vaccination in a person with a history of anaphylaxis to other vaccines or injectable therapies
- Ability of the patient to be vaccinated in a setting where advanced medical care is immediately available for anaphylaxis
- Risk of adverse events after anaphylaxis treatment with epinephrine (older adults with hypertension and atherosclerotic heart disease may be at increased risk for cardiac adverse events following anaphylaxis treatment with epinephrine)
- Whether the patient has previously been infected with SARS-CoV-2 and, if so, how long ago
Vaccines Interim Clinical Considerations
Preliminary data suggest high vaccine efficacy in preventing COVID-19 following receipt of two doses of mRNA COVID-19 vaccine (Pfizer-BioNTech: 95.0%; Moderna: 94.1%). Patients should be counseled on the importance of completing the two-dose series (of the same vaccine product) to optimize protection.
“Before vaccination, providers should counsel mRNA COVID-19 vaccine recipients about expected local (e.g., pain, swelling, erythema at the injection site, localized axillary lymphadenopathy on the same side as the vaccinated arm) and systemic (e.g., fever, fatigue, headache, chills, myalgia, arthralgia) post-vaccination symptoms. Depending on vaccine product (Pfizer vs. Moderna), age group, and vaccine dose, approximately 80–89% of vaccinated persons develop at least one local symptom and 55–83% develop at least one systemic symptom following vaccination,” – CDC warns.
Given the currently limited information on how much the mRNA COVID-19 vaccines may reduce transmission in the general population and how long protection lasts, vaccinated persons should continue to follow all current guidance to protect themselves and others. This includes wearing a mask, staying at least 6 feet away from others, avoiding crowds, washing hands often, following quarantine guidance after an exposure to someone with COVID-19, and following any applicable workplace or school guidance, including guidance related to personal protective equipment use or SARS-CoV-2 testing.