Moderna Inc announced on Thursday, 5 August, that its COVID-19 vaccine was about 93 percent effective for six months after the second dose, with minimal change from the 94 percent efficacy reported in its original clinical trial.
However, as antibody levels are expected to decline in winters, booster shots have been recommended.
In order to maintain a high level of protection, a third shot has been advocated by Moderna, Pfizer Inc and BioNTech.
Moderna CEO Stephane Bancel recently announced that the company would produce around 800 million to 1 billion doses of the vaccine that it has targeted this year.
Bancel was quoted as saying, "We are now capacity constrained for 2021, and we are not taking any more orders for 2021 delivery," Reuters reported
Meanwhile, Pfizer and BioNTech said last week that their vaccine's efficacy declined around 6 percent every two months, coming down to around 84 percent after six months of the second shot.
Bancel further added, "Our COVID-19 vaccine is showing durable efficacy of 93 percent through six months, but recognise that the Delta variant is a significant new threat so we must remain vigilant."
The Delta-variant, first identified in India, has now spread to 135 countries as per the World Health Organization. In view of this, it is being debated if it is safe to take additional doses, how effective they will be and if they are a necessity.
Meanwhile, Pfizer is also planning to seek approval for a third shot later this month.
Moderna's Three Booster Candidates
Moderna, in its study of three different booster candidates, observed strong antibody responses being induced against the Gamma, Beta and Delta variants.
Moderna has signed vaccine contracts worth $20 billion in sales for this year. It further expects to produce between 2 billion and 3 billion doses next year, having agreements for $12 billion in 2022.
Pfizer on the other hand, expects to manufacture as many as 3 billion doses within 2021 with sales to top $33.5 billion.
Since United States authorized Moderna's vaccine for emergency use in adults in December, it has been cleared for emergency or conditional use in adults in more than 50 countries.
Moreover, the company expects to finish its submission for full approval with the US Food and Drug Administration this month.
(With inputs from Reuters)
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