Why is the potential vaccination of AstraZeneca more exciting than you think?


Over the past three weeks, the world has heard a sigh of relief from the positive news of coronavirus vaccine trials. Pfizer (NYSE: PFE) and partner BioNTech (NASDAQ: BNTX), Modern (NASDAQ: MRNA), and AstraZeneca (NASDAQ: AZN). But while the market has enjoyed more than 90% efficacy for the first two vaccine candidates, the results of AstraZeneca’s clinical trials have met with a shrug. Despite the market reaction, I believe that investors should be more excited about the potential AstraZeneca vaccination than their efficacy data suggests.

When efficiency is not really efficiency

With so many vaccines under development — the New York Times lists Coronavirus Vaccine Tracker 74 in clinical trials or authorized for limited use — it can be difficult to understand what makes any vaccine better than others. One clear method is to know how effective they are in preventing the disease. But as it turns out, even that can be a little misleading.

clinician inoculates the globe in his hand

Image source: Getty Images.

The recent announcement by AstraZeneca and the University of Oxford that our vaccine candidate is 70% effective in preventing COVID-19 requires a little more digging. This number came from two arms of the vaccine trial, one receiving two full doses of vaccine per month and one receiving initially only half the dose. When reviewing each arm individually, it is clear that the cohort that received only half the dose initially showed 90% efficacy. This is not too different from the Moderna and Pfizer candidates, which showed 94.5% and 95% efficiency, respectively.

Although the difference in efficacy may disappear with more data collection, the researchers have at least two theories as to why a lower initial dose may have led to a better prevention rate. First, a lower starting dose of the vaccine can only do a better job of stimulating immune cells that produce antibodies. Another theory is that the vaccine elicits an immune response to both SARS-CoV-2 and the adenovirus used to deliver the vaccine to cells. If the vaccine triggers a response to the virus used to deliver it, most of the vaccine will be able to become cells by halving the initial dose. This explanation is also supported by studies in non-COVID-19 mice, in which a lower starting dose of the vaccine better established the memory immune cells required for the second dose.

Why efficiency is not the most important factor

So far, the vaccines that report results have shown remarkable efficacy. After all, the lower-performing arm of the AstraZeneca study showed 62% effectiveness – better than most annual versions of the flu vaccine, which range from 40% to 60%. Once you receive a reasonably effective vaccine, other factors contribute much more to how many people are vaccinated and whether a disease eventually slows down or can even be stopped.

How easy it is to produce and distribute a drug, regardless of whether it causes side effects and how it affects different groups of people, are all aspects that can cause a scientific miracle to get stuck in the laboratory – a widely accepted standard. Unlike the Pfizer-BioNTech partnership or Moderna gene-based vaccines, the AstraZeneca vaccine relies on chimpanzee adenovirus. The former two vaccines are based on synthetic messenger RNA (mRNA) technology, which has never been used in FDA-approved drugs. The use of chimpanzee adenovirus by AstraZeneca was first published in 1984 and is now widely used to deliver drugs.

Another key element is transmission. While neither Pfizer nor Moderna was evaluated to limit transmission — only those with symptoms were tested — participants in the AstraZeneca study regularly spurred themselves to see if they had symptoms or not. Based on the data collected, the researchers believe that the vaccine actually prevents the transmission of COVID-19, even from those who have no symptoms. In addition, the vaccine not only protected all ages, but also produced the same amount of antibodies in the participants, whether they were young or old – a big sign because the disease often affects the elderly the most. AstraZeneca did not report any serious illness in the 23,000 subjects.

The logistical challenges involved in producing and transporting millions of doses of the vaccine could make the difference between a cool scientific breakthrough and the end of a pandemic. While the Pfizer vaccine should be stored at a negative 94 Fahrenheit, which requires a special case and dry ice delivery, the AstraZeneca vaccine can be stored at normal refrigeration temperatures. This is an advantage over the Moderna vaccine, which can be stored at normal refrigeration temperature for one month, but requires a negative 4 Fahrenheit for longer storage. Most countries either do not have “cold chain” capabilities to store these vaccines for a very long time, or their capacity is extremely limited.

The main causes of arousal

It may seem that all of these reasons are enough to get me excited about the AstraZeneca vaccination, but I haven’t even gotten to the best parts: cost and manufacturing. While Pfizer and Moderna have agreements in place for vaccines ranging from $ 20 to $ 40 per dose, AstraZeneca has promised not to make a profit during the pandemic. Its price, about $ 2.50 per dose, coupled with less stringent cooling requirements, makes vaccination significantly easier in countries where there is no wide social safety net or relatively rich population. This may not seem so important if you’re sitting in front of a computer in the Western world, but in the words of a public health expert at Oxford University, “no one is safe until everyone is safe”.

Unlike Pfizer and Moderna, who together believe they will produce enough doses for 20 million people by the end of the year, AstraZeneca plans to have 200 million doses ready by the end of 2020, 700 million by the end of March 2021, and 3 billion doses next year. Of the reasons excited about the AstraZeneca vaccination, this is my absolute favorite: manufacturing. This ratio will be enough to satisfy the major pharmaceutical company’s agreement with the US for 300 million doses and with Europe for 400 million. It is not clear how many doses will initially be available in Europe and the United States, but ending the pandemic means that more people will need to be vaccinated. What I can tell you is, AstraZeneca has only made the biggest leap towards this goal, despite the weak market reaction.