Dr Noor Hisham Abdullah says the National Pharmaceutical Regulatory Agency will keep tabs on data and analysis on the use of the vaccine, which has yet to be deployed in Malaysia.

The CDC and FDA say the matter requires more investigation.

China's medical products regulator — the National Medical Products Administration — is said to have been leading the talks with Pfizer since late last month.

The vaccine – currently provided for free to all by the government – is expected to be made available at no cost to people who have private insurance or government paid insurance.

Pfizer says it has already delivered 400 million vaccine doses in 79 countries under the US government contract.

While Paxlovid is widely available in many rich countries, availability has been severely restricted in poorer ones, echoing the disparities in the global Covid-19 response.

It accuses them of copying technology that Moderna developed years before the pandemic.

The ombudsman says consequential instant messages should be recognised as EU documents falling under transparency rules, recorded and made available for freedom of information requests.

Advisers to the US Food and Drug Administration are scheduled to meet on Tuesday to discuss whether to update Covid-19 vaccines for the fall.

An analysis of a subset of participants showed antibody levels were similar to 16- to 25-year-olds who were given the full strength vaccine at two doses.

It is unclear how much demand there is for the third dose in the age group.

The company is also focused on a Covid-19 vaccine booster that provides immunity for a year.