How does Covaxin stack up against other Covid-19 vaccines?

Bharat Biotech's Covid-19 vaccine Covaxin, which faced flak for being approved without late-stage efficacy data, has shown an interim efficacy of 81 per cent against the novel coronavirus in Phase III clinical trials.

Prime Minister Narendra Modi on March 1, 2021, took the indigenous Covid-19 vaccine and was the first to get the jab leading India's inoculation drive in its second phase. Applauding the Prime Minister, Union Health Minister Harsh Vardhan had said by taking Covaxin, he has effectively ended any spread of misinformation and it would also eliminate hesitancy from the minds of people about this home-grown vaccine.

Here is how does Covaxin stack up against other Covid-19 vaccines:

In January, along with Covaxin, India's drugs regulator had approved Oxford University-AstraZeneca vaccine, marketed as Covishield in India, manufactured by the Serum Institute of India, for restricted emergency use in the country. Meanwhile, the USFDA has given emergency authorisation to the Johnson & Johnson, Moderna and Pfizer-BioNTech vaccines.

Also read: After Covishield and Covaxin, these Covid-19 vaccine candidates in the race

Efficacy data

The Covid-19 vaccine developed by AstraZeneca and Oxford University showed an average efficacy of 70.4 per cent in a pooled analysis of interim data from late-stage trials. The half-dose first regimen was found to be 90% effective in a subset of trial subjects. The success rate was 62% with the originally planned two full doses, based on interim data.

Meanwhile, Bharat Biotech's interim efficacy trend of 81 per cent, analysed as per the protocol approved by the DCGI, put it at par with other global front-runner vaccines.

The Pfizer-BioNTech and Moderna vaccines were found to be more than 90 per cent effective.

Efficacy against variants

Preliminary research shows the two vaccines against Covid-19 approved in India, Covaxin and Covidhsield, are effective against the UK variant of the novel coronavirus but there is no data on their efficacy against the South African and Brazilian mutations detected in the country.

Pfizer-BioNTech's vaccine, based on a different technology than AstraZeneca's vaccine, is expected to be much more effective in protecting against the onset of Covid-19 transmitted through the South African variant.

Moderna’s vaccine is effective against new variants of the coronavirus that have emerged in Britain and South Africa, the company announced. But it appears to be less protective against the variant discovered in South Africa, and so the company is developing a new form of the vaccine that could be used as a booster shot against that virus.

Cost of the vaccines

Moderna said that they would charge governments between $25 and $37 per dose. Pfizer Inc, which had withdrawn an application for emergency-use authorisation of its Covid-19 vaccine in India, is priced at $37 per dose in the US.

Meanwhile, the coronavirus vaccine developed by AstraZeneca and the University of Oxford costs $3-4 per shot (Rs 219-292) to the Indian government and will be priced at double that rate in the private market ones such sales open up.

The Indian Health Ministry has said that all vaccines provided to beneficiaries at government health facilities will be entirely free of cost, while private facilities cannot charge the beneficiary a sum above Rs 250 per person per dose (Rs 150 for vaccines and Rs 100 as operational charges).

Analysts estimate that India may buy about 680 million doses of Pfizer Covid-19 vaccine, which means it would spend about $1.9 billion if the vaccine was priced at $3 per dose. Pfizer's vaccine at $37 per dose, would up the price by 12 times to a whopping $22.8 billion.

Side effects

For Covishield, possible adverse events following immunisation (AEFIs) are injection site tenderness, injection site pain, headache, fatigue, myalgia, malaise, pyrexia, chills and arthralgia, and nausea.

Very rare events of demyelinating disorders have been reported following vaccination with this vaccine without the causal relationship establishment.

For Covaxin, AEFIs include injection site pain, headache, fatigue, fever, body ache, abdominal pain, nausea and vomiting, dizziness-giddiness, tremor, sweating, cold, cough and injection site swelling.

Although not seen in its clinical trial, Pfizer's vaccine has been linked with a few cases of severe allergic reactions as it has been rolled out in the UK and the United States. Britain's medical regulator has said anyone with a history of anaphylaxis, or severe allergic reactions to medicine or food should not get the Pfizer/BioNTech Covid-19 vaccine.

(With agency inputs)