Another blow has been dealt to the Oxford/AstraZeneca COVID vaccine after the recent worries surrounding a potential link to blood clots undermined confidence in the vaccine, despite an EU investigation declaring it safe. On Monday, March 22, AstraZeneca published the interim results for its long-awaited COVID-19 vaccine phase III clinical trial in the US. The preliminary data show that the vaccine has overall efficacy of 79 percent and 100 percent efficacy against severe or critical disease, hospitalization, and death.
However, in announcing the interim results in a press release, AstraZeneca appears to have jumped the gun. The press release stated that the US Data and Safety Monitoring Board (DSMB) had not identified any safety concerns related to the vaccine. Later in the day, however, the DSMB published a statement of concern that the AstraZeneca release didn’t use the most up-to-date data on the efficacy of the vaccine, which could alter the findings.
“The DSMB expressed concern that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data. We urge the company to work with the DSMB to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible,” the DSMB statement on the National Institute of Allergy and Infectious Diseases (NIAID) website reads.
The data published was collected up to February 17 (the trial is ongoing) and the DSMB raised concerns that releasing this data now made the vaccine looked more favorable than more recent data from the vaccine study shows. This doesn’t mean that the vaccine is ineffective or dangerous, but such a statement on partial data might lead to confusion once the complete data is published.
“I was sort of stunned,” director of NIAID Dr Anthony Fauci told STAT news. “The data safety and monitoring board were concerned that the data that went into the press release by AZ was not the most accurate and up-to-date data. That is what the DSMB communicated to AZ in a rather harsh note. Having seen that letter we could not just let it go unanswered.”
It's unusual for a data safety monitoring board to intervene in public, but Dr Fauci felt that if they didn’t speak up, NIAID might later be accused of covering something up and they did not want to be in that position. AstraZeneca on its part has put out a press statement announcing that it will release the full clinical trial data this week, and that its data collected since February 17 was consistent with that outlined in the interim results published.
“We will immediately engage with the independent data safety monitoring board (DSMB) to share our primary analysis with the most up-to-date efficacy data. We intend to issue results of the primary analysis within 48 hours,” AstraZeneca said.
Experts are concerned that the "drama" surrounding the vaccine will contribute to hesitancy using it. Much of it has little to do with the vaccine itself and more with the politics of vaccine nationalism between the US, the UK, and the European Union. Recently several EU countries put the use of the vaccine on official pause while an investigation concerning potential risks of blood clots linked to the vaccine took place. The European Medicine Agency found that the vaccine doesn't increase the risk of blood clotting and many countries resumed issuing the vaccine immediately.
Dr Fauci himself told Good Morning America that the press release was an error by the company, but "The fact is this is very likely a very good vaccine, and this kind of thing does … nothing but really cast some doubt about the vaccines and maybe contribute to the hesitancy," the Guardian reports.
Two population-wide early studies from the UK on people that have been vaccinated so far with the Pfizer-BioNTech and Oxford/AstraZeneca vaccines have shown both show great efficacy, with the risk of hospitalization for COVID-19 reduced by 94 percent four weeks after receiving the first AstraZeneca jab.
For more information about COVID-19, check out the IFLScience COVID-19 hub where you can follow the current state of the pandemic, the progress of vaccine development, and further insights into the disease.
1