Moderna says its COVID-19 vaccine provides one year’s immunity

Moderna has announced that its COVID-19 vaccine should provide immunity for at least one year, adding that it is on track to deliver at least 600 million doses of the vaccine in 2021.

Speaking at a conference on Monday, Moderna CEO Stéphane Bancel said that the immunity generated by his company’s vaccine should last for at least a year.

Clinical trials showed the vaccine to be highly effective at preventing disease, but they do not show precisely how long this immunity will last.

It may be the case that recipients of the vaccine will need to re-take the vaccine regularly to boost their immunity, a typical exercise for most vaccines, which have a specific duration of immunity that can range from a few months to decades.

For example, the season flu vaccine only lasts for a matter of months, while the measles vaccine immunises against measles for life, with the magnitude of variation being the result of the unique combination of characteristics of viruses and vaccines.

The duration of the immunity provided by the COVID-19 vaccine is to date unknown, with data from the extensive clinical trials conducted unable to tell us how long any immunity lasts. The duration will become clearer over time as manufacturers and regulators continue to monitor the situation.

The developments of new variants of the virus that can also learn to evade the protection offered by vaccines will also continue to be monitored, and Moderna said it is well placed to respond to new variants of coronavirus, such as highly infectious variants currently spreading through South Africa and the UK, owing to the adaptable mRNA technology used to develop the vaccine.

Pfizer, BioNTech and Moderna are all using this new type of technology for vaccines based on messenger RNA (mRNA). Unlike many other vaccines which rely on weakened or dead viruses that must be grown in vast quantities, this molecule can simply be tweaked as needed and put back into the vaccine.

“mRNA is fantastic because you can just swap a new strain and run with it,” said Mr Bancel.

Mr Bancel’s comments follow earlier statements from manufacturers at Pfizer and BioNTech, who pointed out the relative ease with which the vaccine’s core components can be edited to adapt to new variants.

In addition to discussing the duration of the Moderna vaccine’s immunity, Mr Bancel said the company is “very comfortable” with its track record at producing vaccines, adding that it is on track to deliver between 600 million and 1 billion doses by the end of the year.

The company, which has never brought a product to market before, predicted $11.7 billion in vaccine-related sales this year based on advance purchase agreements signed with governments.