SHBC1632

L.Y.TAN¹, M.HUANG¹, K.W.TAN¹, W.L.DAVID NG¹, S.X.POON¹, R.M. BALASUBRAMANIAM¹, H.C.LAM¹, S. LITSHUMANAN¹

National Healthcare Group Polyclinics¹

Toa Payoh Polyclinic started providing mRNA COVID-19 vaccinations (Pfizer-BioNTech/Comirnaty) since January 2021. The vaccine consists of two doses, 3-8 weeks apart. Patients who have received the vaccine are observed for adverse effects for 30-minutes before discharge. We sought to describe the common adverse effects patients experienced within this 30-minute period.

We audited records of patients who required a doctors’ consultation within 30 minutes post-vaccination. Adverse effects were noted. Patients who reported reactions beyond the 30-minute period were not included in this audit.

From January to June 2021, a total of 24300 doses were administered. Of these, 13136 were first doses, and 11164 were second doses.

40 patients reported side effects in dose 1 (0.30%). The commonest reactions documented were nausea (15%), rash and itch (15%), chest pain, fatigue, throat tightness (12.5% each) and shortness of breath (10%). 3 patients were treated for suspected anaphylaxis with intramuscular adrenaline.

8 patients reported side effects in dose 2 (0.07%). The commonest reactions documented were giddiness (25%), myalgia (25%), headache, shortness of breath, hypertension, chills, and throat tightness (12.5% each). None were treated for anaphylaxis.

We focused on the immediate post vaccination period in this audit, and therefore the frequency of adverse effects were much less compared to existing literature. There was a difference in the type of symptoms between dose 1 and 2.

This information is useful to update vaccination centres with the common symptoms to expect and manage in the immediate post-vaccination period.