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Safety of mRNA Vaccines in Persons with Anaphylaxis

        The Expert Committee on COVID-19 Vaccination (EC19V) recommends extending the use of the mRNA COVID-19 vaccines from Pfizer-BioNTech and Moderna to persons with a history of anaphylaxis not related to the mRNA vaccines. 

2.     Anaphylaxis is a potentially life-threatening allergic reaction. Previously, the EC19V had recommended that persons with a history of anaphylaxis should not receive the mRNA-based COVID-19 vaccination. This was out of an abundance of caution in light of some overseas and local reports of anaphylaxis with the mRNA-based vaccines in individuals with a history of allergies, when the mRNA vaccines were first introduced. 

3.     Local and international data indicates that mRNA vaccines are suitable for use in persons with anaphylaxis not related to mRNA vaccinations or its components. To date, more than 200 million doses of mRNA-based vaccines (both Pfizer-BioNTech and Moderna) have been administered worldwide. The data has been reassuring, and there are no safety issues detected with vaccinating individuals with a history of anaphylaxis to other triggers. The incidence rate of anaphylaxis reported locally with these mRNA vaccines has also stabilised at about 0.85 per 100,000 doses administered, a rate comparable to that reported internationally. 

4.     EC19V now recommends that persons with a history of anaphylaxis or allergic reactions to other drugs, food, insect stings, or unknown trigger (idiopathic) can be vaccinated with a 30-minute observation period after vaccination. 

5.     Individuals with a history of anaphylaxis to any component of the mRNA COVID-19 vaccine are still not recommended to receive the mRNA COVID-19 vaccine. Individuals who have an anaphylactic reaction after the first dose of mRNA vaccine should not receive the second dose. Non-mRNA vaccines may be authorised for use by HSA and be made available in the future, hence these individuals are advised to wait for these vaccines instead.

6.     Where individuals had a history of allergies to other vaccines, because there may be similar components in these vaccines as the mRNA vaccines, these individuals should be first be referred to an allergist for further evaluation and if deemed suitable, may be vaccinated with the mRNA vaccines. 

7.     The Expert Committee on COVID-19 Vaccination will continue the review emerging safety data with the view of allowing more persons who remain contraindicated to be vaccinated with mRNA vaccines if it is safe. 

4 JUNE 2021

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