Covaxin is an inactivated vaccine. It contains the dead virus, which prompts an immune response but doesn’t infect or make the person sick.
Covaxin requires two doses which should be given 28 days apart and can be stored at a normal refrigerator temperature of 2-8 degrees celsius. It has a shelf life of 24 months.
The Covishield is made from a weakened version of a common cold virus, called adenovirus, from chimpanzees and has been modified to look more like coronavirus.
In the last week of March, the Indian government increased the interval between the first and second doses of Covishield from 4 to 8 weeks. It has a shelf life of 9 months at a normal refrigerator temperature of 2-8 degrees celsius.
Like Covishield, Sputnik V is consists of an engineered virus without the ability to replicate or multiply, which when injected into the human body, triggers an immune response to the coronavirus spike proteins.
The regimen comprises two doses to be administered 28 days apart. Like its Indian counterparts, Sputnik too remains stable at 2-8 degrees celsius.
Which is more effective vaccine?
All three vaccines have shown promising results in their respective clinical trials.
The updated second interim phase 3 trial data shows that Covaxin has an efficacy rate of 78%, a tad lower than the earlier reported efficacy of 80.6% based on the first interim trials conducted in March. The efficacy against severe COVID-19 disease was 100%, the company claimed, but that against protecting from asymptomatic COVID-19 infection was 70%. The vaccine can induce antibodies that can neutralize even the UK strain and other heterologous strains.
Covaxin is successful in protecting against both, the UK and Brazilian variants.
The peer-reviewed results of the Phase-III trials of the Covishield show that it is up to 90% effective. The results also revealed that the vaccine was only 62% effective when participants were given two full doses, but its efficacy rose to 90% when a half dose followed by a full dose was administered. In all likelihood, the vaccine will be effective against the new strain as well.
Covishield works effectively against the UK strain and is being tested against the Brazilian variant.
Manufacturers of the Sputnik V vaccine released a statement detailing an impressive 95 percent efficacy rate. Preliminary data from volunteers obtained 42 days after the first dose or 21 days after the second dose indicates Sputnik V’s efficacy is above 95 percent.
According to the makers of the vaccine, Sputnik is one of the best options against the mutations of the virus as it is the only one that uses two totally different shots.
Covishield does have a few side effects, such as pain, redness, itching, swelling or bruising, feeling unwell, fatigue, chills, fever, headache, nausea, joint pain, and muscle ache, but they are mostly mild to moderate in nature and can be treated with over-the-counter pills.
Along similar lines, Covaxin too has induced side-effects including site pain, injection site swelling, injection site redness, injection site itching, stiffness in the upper arm, weakness in the injection arm, body ache, headache, fever, malaise, weakness, rashes, nausea, vomiting.
However, Covaxin is less likely to cause any allergic reaction.
Sputnik too, has short-term minor adverse events such as pain at the injection point and flu-like symptoms including fever, weakness, fatigue, and headache. No unexpected adverse events were identified as part of the research.
It should not be administered to anyone in an acute stage of allergic reaction. One should get blood tests done for Immunoglobulin E and C-reactive protein in case of allergies, and if they aren’t within the normal limit, they should reconsider getting the Sputnik jab.
Price of Covishield at Rs 300 per jab for state governments and Rs 600 per dose for private hospitals.
Price of Covaxin, at Rs 600 per dose for state governments, while it will cost Rs 1200 per dose for private hospitals.
Note that, as of now, both vaccines are being administered free of cost in government centres and for INR 250/dose in private centres. There is no price difference between the two vaccines for citizens.
It remains unclear how much private and government vaccination centres will charge for Sputnik V.