An Oxford University and AstraZeneca statement on Wednesday revealed that the coronavirus vaccine which is expected to cost less than a cup of coffee might not be as effective as the world was led to believe when it was announced that the AstraZeneca vaccine recorded a success rate of 90% during its trials. One of the UK’s foremost universities and the manufacturer of the vaccine explained in the statement that there was an error in the production of the vaccine.
Some of the participants of the trial earlier reported that they were not given a complete dosage of the vaccine, surprisingly those in this group appear to show more resistance to the coronavirus than those who received their full dosages. The 90% effectiveness that was earlier announced is for the low dose group while the vaccine only recorded about 62% efficacy in participants who got full dosages of the vaccine. Together, the vaccine seems to be 70% effective in protecting against COVID-19.
Public health experts have become very worried about the efficacy of the vaccine because of the way the results were obtained. The trials for the vaccine are being carried out in the UK and Brazil. In the low dosage group, participants are below the age of 55 and only 2,741 people participated in the group. The high dosage group cuts across people of different ages and had total participants of 8,895.
Experts are worried that the 90% efficacy in the first group is only because the participants were lower than the other group and contained young people who naturally show more resistance to the virus, AP News wrote. According to Oxford, there was a problem in the concentration of the vaccine leading to the low dose given to some of the first group of participants. The statement from the university also stated that the problem has been discussed with regulators and corrected.
David Salisbury, Associate Fellow at Chatham House think-tank, explained that it is impossible to bring the results of the two trials with so many variables together to reach a success rate of 70%.
“That’s two different studies with different doses and the initial results of 70% success rate represent neither the 90% of the high dosage group nor the 62% of the other group,” Salisbury explained.
The Oxford researchers involved in the production of the vaccine have admitted that they are not sure of the reason for the different results but are looking into it. Sarah Gilbert, one of the researchers said that the solution is getting the perfect dose of vaccine that can trick the immune system into fighting off the virus.
Head of the United States’ Operation Warp Speed, Moncef Slaoui told reporters on Tuesday that investigations are being carried out in the US to ascertain the efficacy of the vaccine and that the vaccine may be modified to include only half of the dose for patients in the United States.