CANADA BANNED USE OF ASTRAZENECA VACCINE FOR THOSE BELOW 55 YEARS
(RELEVANCE: G.S paper II: International Relations & G.S paper III: Science and technology)
WHY IN NEWS?
Canada’s National Advisory Committee on Immunization (NACI) has recommended that the AstraZeneca Covid-19 vaccine not be used for individuals below the age of 55.
The committee stated that until a type of an adverse event associated with the vaccine is investigated, its usage should for those below the age of 55 be stopped. Even so, individuals above the age of 55 can continue getting the AstraZeneca vaccine in Canada, considering that the adverse event is more common in people below the age of 55.
REASON WHY CANNADA HAS BANNED
Canada has decided to suspend the use of AstraZeneca because of an adverse event referred to as Vaccine-Induced Prothrombotic Immune Thrombocytopenia (VIPIT). “A combination of thrombosis and thrombocytopenia, in some cases accompanied by bleeding, has been observed very rarely following vaccination with the AstraZeneca COVID-19 Vaccine.
This adverse event has led to rare cases where people have experienced the formation of serious blood clots. This is because VIPIT is associated with the creation of antibodies that can activate platelets, which then stimulate the formation of clots and result in thrombocytopenia (a condition characterised by lower than normal levels of platelets in the blood).
Symptoms to look out for this adverse event include shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms including sudden onset of severe or persistent worsening headaches or blurred vision, skin bruising (other than at the site of vaccination) or petechiae (unraised, round red spots under the skin caused by bleeding).
How can the vaccine lead to VIPIT?
It is not clear how exactly the vaccine triggers VIPIT and NACI has said the adverse event has not been associated with an mRNA vaccine till date. The AstraZeneca vaccine is not an mRNA vaccine. mRNA (messenger RNA) vaccines work by encoding instructions that inform the body’s cells to create the spike protein of the SARS-CoV-2 virus. The creation of this spike protein should then trigger the immune system to develop antibodies to fight the disease.
The AstraZeneca vaccine, on the other hand, uses a weakened version of a common cold virus called the adenovirus from chimpanzees. Once injected, this weakened version of the virus which has been made to resemble the coronavirus (which does not cause people to fall ill) should trigger an immune system response and lead to the creation of antibodies.
What is India’s position on using AstraZeneca?
In India, the Oxford-AstraZeneca vaccine is called Covishield, which is manufactured by the Serum Institute of India (SII) in Pune and is one of the two vaccines being administered as part of the Emergency Use Authorisation (EUA). So far, the Indian government has said that there are no signs of concern for using the vaccine manufactured at SII. In fact last week, India temporarily halted the export of the vaccine in order to meet domestic demand as India is experiencing a surge in COVID-19 cases.
Earlier this month, Ghana became the first country in the world to receive a shipment of coronavirus vaccines under the COVAX program, which is led by the vaccine alliance GAVI, the World Health Organisation (WHO) and the Coalition for Epidemic Preparedness Innovations (CEPI) in partnership with UNICEF, vaccine manufacturers and the World Bank, among others to ensure equitable distribution of COVID-19 vaccines globally
About 600,000 doses of the Oxford-AstraZeneca vaccine, manufactured at SII (the largest vaccine manufacturer in the world), were sent to Accra in Ghana.