NEW DELHI: AstraZeneca
had stitched a licensing deal with the Serum Institute of India
last year to produce one billion doses of Oxford University’s Covid-19 vaccine for lower-income countries.
The deal was worked out before well before the vaccine showed effectiveness in dealing with the Covid-19 virus. Covishield
or AZD-1222 makes use of a viral vector made using a weakened strain of the common cold virus (adenovirus), which contains genetic material similar to that of SARS-COV-2. Upon administration, the body's defences recognize the spike protein and prepare antibodies to evade out the infection.
It was one of the first two vaccines - the other being Bharat Biotech's Covaxin- to get approval in India.
Here are the answers to some of the most frequently asked questions about the vaccine:- When should I take my second dose?
The Union health ministry on May 13 increased the time gap between the two doses of Covishield to 12-16 weeks from the earlier 6-8 weeks based on the recommendation of an expert panel.
As per the initial permission granted by the Drug Controller General
of India (DGCI), the second dose of Covishield was to be administered 4-6 weeks after the first dose. Should pregnant women be vaccinated?
While pregnancy puts women at higher risk of severe Covid-19, very little data are available to assess vaccine safety in pregnancy.
Pregnant women may receive the vaccine if the benefit of vaccinating a pregnant woman outweighs the potential vaccine risks.
For this reason, pregnant women at high risk of exposure to SARS-CoV-2 (e.g. health workers) or who have comorbidities which add to their risk of severe disease, may be vaccinated in consultation with their health care provider. Who is the vaccine not recommended for
People with a history of severe allergic reaction to any component of the vaccine should not take it.
The vaccine is not recommended for persons younger than 18 years of age pending the results of further studies. What’s the recommended dosage?
The recommended dosage is two doses given intramuscularly (0.5ml each). Can I just take one dose of Covishield vaccine?
Additional research is needed to understand longer-term potential protection after a single dose. What side effects can I face after getting vaccinated?
A person can develop some symptoms such as pain, warmth, itching, bruising, fatigue, chills, fever, nausea, muscle ache, lumps and malaise.
Severe side-effects such as extremely high temperature (over 102 degrees Farhenheit), coughing, breathing difficulties, nervous problems, anaphylaxis are possible, though rare. It should be noted that the severe reactions, observed during the clinical studies were ruled out to be unrelated to the vaccine. Does mixing of Covid-19 vaccine have any benefits?
While many studies are ongoing, data has recently been released from mix and match trials in Spain and the United Kingdom. This data is very promising, and suggests mix and match schedules may give higher antibody levels than two doses of a single vaccine.
The Spanish study on mixing Covid-19 vaccines has found that giving a dose of Pfizer
's drug to people who already received a first shot of AstraZeneca vaccine is highly safe and effective, according to preliminary results.
The Combivacs study, run by Spain's state-backed Carlos III Health Institute, found the presence of IgG antibodies in the bloodstream was between 30 and 40 times higher in people who got the follow-up Pfizer shot than in a control group who only received one AstraZeneca dose.
Meanwhile, the presence of neutralising antibodies rose sevenfold after a Pfizer dose, significantly more than the doubling effect observed after a second AstraZeneca shot. Is Covishield safe?
Two versions of the vaccine – produced by AstraZeneca-SKBio (Republic of Korea) and the Serum Institute of India – have been listed for emergency use by WHO. When the vaccine underwent WHO Strategic Advisory Group of Experts on Immunization (SAGE) consideration, it had undergone review by the European Medicines Agency
The EMA has thoroughly assessed the data on the quality, safety and efficacy of the vaccine and has recommended granting a conditional marketing authorisation for people aged 18 and above. What is the efficacy of the vaccine ?
The vaccine against Covid-19 has an efficacy of 63.09% against symptomatic SARS-CoV-2 infection.
Longer dose intervals within the 8 to 12 weeks range are associated with greater vaccine efficacy. Does it work against new variants?
Yes, it works against new variants although more study is being done to ascertain if the new variants cause a change in its efficacy.