THE ROLLOUT OF a potential Covid-19 vaccine made by AstraZeneca could be set back after the biotech company announced a pause in tests, the government of Mexico said, which is involved in developing the drug alongside Argentina.

AstraZeneca, which is working on a vaccine in conjunction with Oxford University, said that a volunteer had developed an undiagnosed illness and that, in line with security protocols, it was delaying further tests until an independent panel had studied the case.

AstraZeneca issued a statement last night saying the late-stage studies of the vaccine had been paused while the company investigates whether the patient’s reported side effect is connected with the vaccine.

Information about the patient’s condition wasn’t revealed, other than to describe it as “a potentially unexplained illness”. News site Stat first reported the pause in testing and said the possible side effect occurred in a testing volunteer in Britain, who was expected to recover.

The vaccine, developed by Oxford University, is being tested in thousands of people in Britain and the US, and in smaller study groups in Brazil and South America.

‘Not unusual’

Pausing vaccine trials “is not an unusual occurrence… and as a consequence the vaccine’s arrival may be delayed” across the region, said Hugo Lopez Gatell, Mexico’s undersecretary for health, at a press conference on the latest development.

Gatell asked that people avoid speculation about the safety of the vaccine, especially given that it is considered to be one of the most promising projects under development in the western world.

Mexico and Argentina have signed an agreement to work together with the Swedish-British pharmaceutical company.

Under the plan, some 250 million doses of the vaccine would be sold at cost across Latin America, with the exception of Brazil, which has its own agreements.

Mexico will also work with other labs in Europe, China and Russia in vaccine development projects, although AstraZeneca is the only one that has guaranteed distribution across Latin America.

With a population of almost 129 million people, Mexico had suffered 68,484 fatalities from the virus by Tuesday, with 642,860 cases of Covid-19.

- with reporting from the Press Association