The United Kingdom has had a history of unique and inconsistent approaches to the COVID-19 pandemic. They initially supported unrestricted activity and herd immunity, then shifted to more conservative approaches when infections and hospitalizations skyrocketed. Most recently, they went into total shut down after the finding of a strain with multiple mutations that has become predominant in the London area.
However, the most unusual aspect of the U.K.’s approach to the pandemic has been how they have handled their vaccination campaign. They were the first country in the world to approve the Pfizer vaccine and started immunizations before anyone else. Despite this, they had a number of missteps including suggesting anyone with any type of severe allergy, be it to food, drug or pollen, or anyone who carries an EpiPen, should not receive the Pfizer vaccine. This was after only two allergic reactions and was a much broader caution than that given by regulatory agencies in the U.S. and in the E.U. Most felt this was excessive.
The latest actions taken by the U.K. seem even more confusing. First, they approve the AstraZeneca vaccine well before anyone else took this action. While it was developed at Oxford University in the U.K., approving it at this point given the paucity of data and the low rate of efficacy still came as a surprise.
As a reminder, the AstraZeneca vaccine showed only a 60% efficacy in a trial that had a number of errors including an incorrect initial dose for a small portion of the trial. The company seized on that data since it seemed to show a much better protection rate in that group although later analysis showed that it was not statistically different from the overall 60% protection rate.
At the same time the U.K. approved the vaccine, both the FDA and the EUA (the European Union’s FDA) announced they could not approve the AstraZeneca vaccine based on current data because of the issues in their clinical trial. AstraZeneca also seems to be trying to improve the efficacy of their vaccine as they sought to combine it with a dose of either the Pfizer, Moderna, or even the Russian COVID-19 vaccine. Thus, the AstraZeneca vaccine seems to be a work in progress.
More remarkably, the U.K. is considering essentially doing away with the standard administration protocol for the Pfizer and AstraZeneca vaccines. They plan to immunize everyone with a single dose of either vaccine to attempt to improve on the number of people they vaccinate. They will then wait three months before giving them a second dose of either vaccine. This is a truly radical approach that is without any supporting data.
Some argued against the idea, which was driven by former PM Tony Blair. Professor Wendy Barclay, a member of the government’s New and Emerging Respiratory Virus Threats Advisory Group, told the Commons science and technology committee: “I think that the issue with that is that the vaccine is approved on the basis of being given two doses, and the efficacy is on that basis. To change at this point, one would have to see a lot more analysis coming out from perhaps the clinical trial data.”
Giving only one dose will certainly reduce the efficacy of the Pfizer vaccine to approximately 60 to 70% (not exact since it was not an endpoint in the Pfizer study). The actual efficacy of one dose of the AstraZeneca vaccine is unclear and is open to debate. Prof David Salisbury, a former director of immunization at the Department of Health in England, backed the idea claiming one dose of this vaccine will be 70% effective-which is crazy since that number is better than two doses were in the AZ trial!
Most importantly, there is no data to show that the second dose of the Pfizer vaccine will be as effective if given three months later. This could reduce the overall efficacy of the Pfizer vaccine from the remarkable 95% shown in their phase three clinical trial.
The implications of a vaccine that’s only 50-60% effective are far greater than people realize. Symptomatic infections continue to occur in people vaccinated with a 60% effective, albeit at half the current rate. This was well demonstrated in AstraZeneca’s clinical trial data. it means that this approach will not stop COVID-19 infections and transmission. It may not even reduce the number of sick people that seek medical care. It seems poorly conceived at best.
If the U.K. really wanted to help vaccinate the world more rapidly and effectively, they might consider having AstraZeneca license either the Moderna or Pfizer vaccines to increase production rather than trying to improve their own marginal product.