A coronavirus vaccine being developed by Oxford University and UK-based pharma major AstraZeneca has shown promising results in preliminary trials that involved roughly 1,000 people, by triggering a dual immune response in people aged 18 to 55 that lasted at least two months. It’s a vaccine that will be a pathbreaker in more than one sense if it proves equally effective in larger trials
The novel coronavirus has claimed over six lakh lives so far. While several vaccine types that are capable of protecting billions of people are being tried out, the Oxford University vaccine, also referred to as AZD1222, is similar to another frontrunner that is being made by the China-based CanSino Biologics
These vaccines count on genetically engineered viruses, termed adenoviral vectors, to introduce a weakened Sars-CoV-2 gene into the human body with the objective that it will spur the immune system to produce antibodies that will attack the virus if it thereafter tries to infect us. But no adenoviral vector vaccines have been approved for use, so far, in humans although it has seen use in experimental vaccines
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The Oxford University vaccine is based on a harmless, weakened version of a common cold virus, or adenovirus, that causes infections in chimpanzees. The vector (the carrier) is derived from adenovirus (ChAdOx1) taken from chimpanzees. It is genetically engineered so that it does not replicate in humans. When the genetically engineered ChAdOx1 with the spike protein from coronavirus is given to a person, it causes a build-up of spike proteins. The body’s immune system recognises this and begins to create the antibodies to defeat the foreign object.
a T-cell response — these are a type of white blood cell that “remembers” and attacks the coronavirus — was induced that continued two months after injection of the vaccine. That the vaccine induced T-cells is significant. T-cells can stay in the body for a longer period in a dormant state, and can re-emerge to attack the virus in case of an infection.
There were some side effects such as fever, headaches muscle ache and injection site reactions that were observed in about 60% of patients, but all these were deemed mild or moderate, and were resolved during the trial
Experts have guessed that if it meets all desired goals, the vaccine may be available for use by the end of this year, but it isn’t certain, lead developer of the
