April 08, 2021

Haematological Conditions and COVID-19 Vaccinations

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has a case-fatality rate of 2.3%, with higher rates among elderly patients and patients with comorbidities.

COVID-19 has infected over 175 million people worldwide and has resulted in the deaths of over 3.77 million people worldwide and over 900 deaths in Australia. The most effective way to protect ourselves against COVID-19 is to get vaccinated – this will protect ourselves, our family and friends, and our community.

A very small proportion of patients globally have developed thrombosis with thrombocytopenia syndrome (TTS/VITT) following vaccination with COVID-19 Vaccine AstraZeneca.

  • No specific risk factors have been identified
  • Prevalence is rare (1-2 per 100,000 in Australia) following a first dose of vaccine and very rare (estimated at 1.7 cases per million second doses).
  • The benefits of COVID-19 vaccines outweigh the risk of TTS/VIPIT/VATT/VITT for most people.
  • People who have had the first dose of COVID-19 Vaccine AstraZeneca without any serious adverse effects can be given the second dose, including adults under 50 years of age.

Central Coast Haematology encourages all our patients to proceed with the COVID-19 vaccine as soon as it is available. The current Australian Technical Advisory Group on Immunisation (ATAGI) advice for vaccination in Australia is:

COVID-19 Vaccine AstraZeneca for: People aged over 50 years without any of the following conditions listed below:

  • A past history of cerebral venous sinus thrombosis (CVST)
  • A past history of heparin-induced thrombocytopenia (HIT)
  • A past history of idiopathic splanchnic (mesenteric, portal and splenic) venous thrombosis
  • Anti-phospholipid syndrome with thrombosis
  • People with contraindications to COVID-19 Vaccine AstraZeneca, i.e.
    • Anaphylaxis to a previous dose of COVID-19 Vaccine AstraZeneca, or to an ingredient of the vaccine
    • Thrombosis with thrombocytopenia occurring after the first dose of COVID-19 Vaccine AstraZeneca
    • Other serious adverse events attributed to the first dose of COVID-19 Vaccine AstraZeneca

If any of these conditions are met, then the Comirnaty (Pfizer) vaccine brand is recommended.

Comirnaty (Pfizer) is the preferred vaccine brand for: People aged under 50 years, since the risk of Thrombosis with Thrombocytopenia Syndrome (TTS), albeit very low, appears to be higher in younger adults.

From Monday 24 May, members of the public aged 50 years and over can make an appointment to receive the the AstraZeneca vaccine from the COVID-19 Vaccination Clinic at Wyong Hospital. Vaccinations at this clinic can be booked online from Monday by visiting the COVID-19 Vaccine Eligibility Checker at www.health.gov.au or contacting Health Direct on 1800 020 080.

Members of the public aged 40 to 49 can now also register their interest in receiving the Pfizer vaccine at the COVID-19 Vaccination Clinic at Gosford Hospital via the NSW Government website www.nsw.gov.au