A third dose of vaccines against Covid-19 may not be needed for everyone in the UK and rushing into a nationwide rollout may put extra pressure on the country's already burdened National Health Service (NHS), Pascal Soriot, CEO of AstraZeneca has said.

Soriot's comments come as the UK is just "a few weeks away" away from officially announcing booster doses for all its citizens, The Telegraph reported.

"Moving too quickly to boost across the entire adult population will deprive us of these insights, leaving this important decision to rest on limited data," Soriot wrote in the newspaper.

"A third dose for all may be needed, but it may not. Mobilising the NHS for a boosting programme that is not needed would potentially add unnecessary burden on the NHS over the long winter months.

"Because NHS staff and resources are scarce, another national mobilisation would potentially leave us with fewer resources for cancer screenings and the other care provided by doctors and nurses each day," he said.

The UK drug maker chief noted that "this is important not just for the UK but for the rest of the world".

So far, 1.2 billion doses of AstraZeneca vaccine, Covishield in India, have been distributed.

The booster roll out in the UK is awaiting a green signal from the independent advisory body Joint Committee on Vaccination and Immunisation (JCVI), who are expecting study results on seven different booster vaccines.

Soriot further stated that it is critical to understand the need for a third dose, as the decision will have "real implications for how we deploy scarce NHS resources".

While booster doses may be "a sensible immediate precaution" for the vulnerable, the elderly or those with people with weak immune systems, the decision to jab the entire population must be based on "real world clinical effectiveness data, not simply antibody measurements", they noted.

"Indeed, we don't know what mix of antibodies and T-cells are needed to prevent serious illness -- the so-called correlates of protection. This is why we need the weight of the clinical evidence gathered from real world use before we can make an informed decision on a third dose," they pointed out.

On the other hand, US pharmaceutical major Pfizer's CEO Albert Bourla had announced that Covid vaccine recipients will "likely" need a third dose between six to 12 months after they're fully vaccinated. He also suggested the need for yearly vaccinations against coronavirus.

The US is also expected to soon roll out Covid booster vaccines for all its citizens, even as the World Health Organisation has called for a moratorium on boosters.

The US has already started a third dose for immunocompromised people.

Other countries include Israel, Italy, France, and Russia.