Questions arose about the Oxford vaccine and 90% found ‘only in younger groups’

A US health official has claimed that the dose of the Oxford vaccine that proved to be 90% effective was only tested in people 55 and younger.

Moncef Slaoui, who runs the program to supply vaccines to the United States, said the half-dose regimen, which was discovered by accident, was only given to the younger age groups.

But British scientists have lined up to defend the research, and Oxford University partners AstraZeneca said they are likely to run another global clinical trial, but don’t expect that to stop the jab from getting the green light.

Slaoui, the scientific director of US Operation Warp Speed, suggested that most of the people in the initial trial received a placebo or two full doses, and the effectiveness was 62%, Bloomberg reported. That group included people 55 and older, as opposed to the 90% effective group, which only administered a half dose before a full booster dose.

Visit our Live Blog for the latest updates Live Coronavirus News

Scientists around the world hope to find vaccines that work in older people, who are at higher risk for Covid-19.

The overall Oxford efficacy of two different dosing regimens in a phase three trial was announced last week at a combined figure of 70%.

Based on a subset of data, a half dose followed by a full dose was found to be 90% effective, but the efficacy was 62% for people who received two full doses.

Results from a previous phase two study of the vaccine published in the medical journal The Lancet showed that the vaccine produced a strong response in all age groups.

Professor Andrew Pollard, director of the Oxford Vaccine Group, said last week that the 90% effectiveness finding had already met the “necessary statistical evidence as required by regulators.”

He said more evidence will likely be available next month, but it is “a very significant result even with the numbers we have.”

The 90% efficacy was based on a dosage regimen administered to 2,741 people.

The other regimen, with two doses, involved 8,895 people.

Neither AstraZeneca nor Oxford initially disclosed that the 90% figure was based on adults 55 and younger.

It comes as some American scientists have questioned the lack of detail in the results published last week by AstraZeneca and Oxford.

The New York Times reported that AstraZeneca’s Menelas Pangalos has defended the company’s handling of the evidence and its public disclosures.

When asked why AstraZeneca had not shared the information with the public, he said: “I think the best way to reflect the results is in a peer-reviewed scientific journal, not a newspaper.”

Some experts have also raised questions about the use of two differently designed clinical trials in Britain and Brazil, and the combination of analyzes from both.

They also say that it is unclear how many cases of coronavirus were found in each group in the trial.

John Moore, professor of microbiology and immunology at Weill Cornell Medical College, told the New York Times: “The press release raised more questions than it answered.”

In an interview with the New York Times, Pangalos said the half-dose finding “could end up being a pretty useful mistake.”

He added: ‘I was not putting anyone in danger. It was a dosing error. Everyone was moving very fast.

“We corrected the error and continued with the study, with no changes to the study, and we agreed with the regulator to also include those patients in the study analysis.”

The University of Oxford said it would not comment before the data appears in a peer-reviewed publication.

At a Downing Street briefing tonight, England’s Chief Medical Officer Professor Chris Whitty said the ‘excellent’ Medicines and Healthcare Products Regulatory Agency (MHRA) would assess all data before possible UK implementation and added that “there is always scientific information debate about everything.”

Pangalos said the company is planning a global trial with thousands of people to compare the two dosage regimens.

The Oxford vaccine is much cheaper and can be stored much more easily than the Pfizer / BioNTech and Moderna vaccines, which require very cold temperatures. Russia also claims that its Sputnik vaccine is 95% effective.

In an interview with the PA news agency last week, Tom Keith-Roach, president of AstraZeneca UK, said the UK could receive 19 million doses of the jab by the end of the year if approved.

He also supported the 90% efficacy result, suggesting that it was based on statistically significant data.

Get in touch with our news team by emailing us at [email protected].

For more stories like this, check out our news page.

MORE: How does the Oxford Covid-19 Vaccine Compare to Pfizer and Moderna?