US guidelines for using mRNA vaccines against COVID-19
As with other guidelines on COVID-19, they are likely to be updated frequently.
- The current guidelines only cover the two mRNA vaccines approved in the US (Pfizer and Moderna).
- Both vaccines require two doses – 21 and 28 days apart for the Pfizer and Moderna vaccines, respectively.
- Caution is given it the second dose is given within a shorter window.
- Neither vaccines has a maximum time within which the second dose should be given.
- Although there is no preference between these two vaccines, both doses should be with the same vaccine. There is no data with mixed dosing.
- Any other vaccines should be ideally separated by a two-week window,
- Further boosting doses are not recommended until further data become available.
- Vaccines can be used by people with previous COVID-19.
- To include patient counselling on efficacy and safety.
- People who received monoclonal antibodies against COVID-19 or convalescent plasma are recommended to wait 90 days before using a vaccine.
- People with current symptoms or a recent confirmed exposure should wait until quarantine restrictions are ended before having a vaccine.
The only people who are not recommended to use these vaccines
- Severe allergy after previous mRNA COVID 19 vaccine or any of its components (listed in an appendix).
- Any previous allergic reaction to polyethylene glycol or polysorbate.
- A history of severe allergy reactions to other vaccines, medicines and foods is not a contraindication to COVID-19 vaccines.
- No underlying health conditions are a contraindication against the COVID-19 vaccines.
Several appendices are included on triage for vaccinations, ingredients in each vaccine and characterising allergic reactions.
US CDC. Interim clinical considerations for use of mRNA COVID-19 vaccines currently authorized in the United States. (30 December 2020).