AstraZeneca Pharmaceutical company and Oxford University, both British, have developed a viral vector vaccine. This …
AstraZeneca Pharmaceutical company and Oxford University, both British, have developed a viral vector vaccine. This method uses a vector, i.e. a different virus from SARS-CoV-2, to enter a cell and infect it. In this way, it uses the cellular machinery to produce the spike protein, present in this coronavirus, to generate antibodies.
An agreement between the two institutions to develop a vaccine was announced in April 2020 and the first results were published on 23 November. Updated efficacy data were presented on 22 March 2021. In total, 32,449 people from the US, Peru, Argentina, Colombia, and Chile participated in the phase III trial, which achieved a 79% efficacy.
People vaccinated with AstraZeneca should receive two doses administered over four to 12 weeks. More than 80 countries are currently immunising their citizens with the vaccine, making it the most widely used vaccine worldwide.
Like most formulations, the most common side effects (affecting more than 10% of those vaccinated) are tiredness, general malaise, pain at the injection site, headache, muscle pain, fever, and nausea. Common reactions (one in 10 persons) are swelling or redness at the injection site, fever above 38°C, vomiting and diarrhea. Infrequent consequences are drowsiness, loss of appetite, swollen lymph nodes, excessive sweating, and itchy or rashy skin.
About 20 EU countries temporarily suspended their vaccination programme with the product in early March after several cases of thrombosis (formation of blood clots inside a blood vessel) were reported in people who received the vaccine. The European Medicines Agency EMA confirmed that the formulation is not linked to an increased risk of thrombosis, and a dozen countries resumed vaccination from 18 March.
AstraZeneca’s vaccine will keep for up to six months between 2°C and 8°C.
Biotech and drug company Serum Institute of India, which specialises in making vaccines, reached an agreement with AstraZeneca to market its formulation in India under the name Covishield on exactly the same conditions as in other countries.