A common source of debate, misconception and confusion is "𝘤𝘢𝘯 𝘮𝘺 𝘤𝘩𝘪𝘭𝘥 𝘣𝘦 𝘷𝘢𝘤𝘤𝘪𝘯𝘢𝘵𝘦𝘥 𝘪𝘧 𝘩𝘦/𝘴𝘩𝘦 𝘩𝘢𝘴 𝘢𝘯 𝘦𝘨𝘨 𝘢𝘭𝘭𝘦𝘳𝘨𝘺?".
Especially now with the circulating Pfizer and AstraZeneca (Oxford) COVID19 vaccines, many have asked me about their safety.
But let's start with the basics.
𝐒𝐨 𝐰𝐡𝐲 𝐢𝐬 𝐢𝐭 𝐭𝐡𝐚𝐭 𝐦𝐨𝐬𝐭 𝐨𝐟 𝐭𝐡𝐞𝐦 𝐮𝐬𝐞 𝐡𝐞𝐧𝐬' 𝐞𝐠𝐠𝐬?
The process of growing a virus in an egg leads to that virus becoming less infectious to the human being, but still leading to a protective effect against potential infections in the future.
After a virus is injected, the egg will be sealed with gelatine. This is normally made from pork protein.
On the process of collecting the grown virus from the egg, a small amount of protein will come along as well. This can potentially lead to an allergic reaction.
Saying this, other components might lead to allergic reactions.
𝘛𝘩𝘦 𝘚NIFFLE 𝘴𝘵𝘶𝘥𝘪𝘦𝘴 have shown the safety of the Nasal Flu vaccine.
Several studies have shown that the LAIV (Live Attenuated Influenza Vaccine) that contain less than 0.12μg/mL (so 0.06 μg for a 0.5 mL dose) is safe for patients with an egg allergy.
To produce this vaccine, the virus is grown on chick embryonic fibroblast cells.
In case a patient with an egg allergy needs this vaccine, there two other options that can be used, as they do not contain egg:
𝐘𝐞𝐥𝐥𝐨𝐰 𝐟𝐞𝐯𝐞𝐫 𝐯𝐚𝐜𝐜𝐢𝐧𝐞
Finally, the COVID19 vaccines:
The only children who need to be vaccinated in a hospital are those with an allergy to eggs, with previous anaphylaxis to egg or who had a cardiorespiratory reaction needing admission to Intensive Care or those with coexisting active, chronic asthma.
Dr Costa is a Consultant Paediatrician and fellow of the Royal College of Paediatrics and Child Health.