Moderna announced Thursday a 4.3% increase to $19.2 billion to its 2021 sales forecast for the coronavirus vaccine.

The announcement from the US biotech firm came as vaccine producers are trying to ramp up supplies to match with the demand of countries looking to stock up for next year.

Moderna also gave updates to its initial studies on those aged 12-17 and said trials show the vaccine has an efficacy rate of 96%.

The company has also been working to extend the storage time of the vaccine in refrigerator temperatures.

The ongoing development data related to the current formulation "could support a 3-month refrigerated (2-8°C) shelf life for the vaccine in alternative formats to facilitate easier distribution to doctor’s offices and other smaller settings, if authorized," said Moderna.

The current version of the vaccine is approved for storage for up to one month at refrigerated temperatures, 2-8°C (36-46 F) and up to 7 months in a standard freezer, -20°C (-4 F).