Both companies strongly believe that the third jab will improve the vaccines efficacy rate and could potentially boost individuals against contagious variants.
The move comes amid fears that the delta variant is behind the latest outbreaks in Asia and Africa and rising cases in Europe and the US which scientists currently have discovered how it evades the human immune system.
According to a new study published on Thursday in Nature, the delta variant was found to be able to evade antibodies that target certain parts of the virus.
The findings provided an explanation for diminished effectiveness of the vaccines against delta, compared with other variants.
Delta variant, that bears it origin from India, is believed to be about 60 % more contagious than the alpha variant that brought Britain and other European countries down health-wise.
A further finding from the study found that delta was barely sensitive to one dose of vaccine, confirming previous research that suggested that the variant can partly evade the immune system although to a lesser degree than beta, the variant first identified in South Africa.
Based on drop-offs in efficacy seen in Israel after six months, the companies said they believe a third dose may be needed within six to 12 months after full vaccination.
Separately, countries across the globe are experiencing a resurgence in COVID related cases with reporting 949 new cases and 49 deaths in a single day, Australia records 44 new cases as it goes into its third week under lockdown measures and countries like Vietnam and South Korea facing a looming lock-down measure.