The vaccine against SARS-CoV-2, developed by Oxford University and pharmaceutical AstraZeneca, seems to be making a major contribution to the fight against coronary artery disease. Although its claimed efficacy is slightly lower than the 95% efficacy that Pfizer/BioNTech and Moderna claim, it has many advantages. The main questions about the SARS-CoV-2 vaccines are answered in this article.

How sure is it that the three vaccines also make their claimed efficacy come true in practice?

That is not certain yet. What we know about their effectiveness is based on press releases. None of the three vaccines are already available for peer review.

Pfizer / BioNTech involves definitive research results and a claimed 95% efficacy. Moderna and the Oxford Vaccine are preliminary results of ongoing studies. Moderna claims 94.5 percent efficacy.

The AstraZeneca / Oxford Vaccine has been tested in two ways. Of the more than 23,000 research participants, half received placebo. Of the remaining 11.636 study subjects, 2,741 received a half dose of the vaccine first and a full dose at least one month later. In that group, according to the makers, the vaccine had 90% efficacy.

The remaining nearly 8,900 subjects received two full doses with at least one month apart. In that group, the vaccine efficacy was 60 percent. On average over the whole study group and the two different doses combined, this resulted in 70 percent efficacy. So it seems logical that the vaccine will be used with half, followed by a whole dose.

At an international press conference, professor Andrew Pollard, the leader of the Oxford Vaccine Group, said that he hopes to make all the research data available today or tomorrow for review.

Vaccines are tested in large, strictly controlled trials. Is there any guarantee that the results will be the same in practice?

The efficacy of a vaccine is established in a large trial with several tens of thousands of participants. A study like this shows how well a candidate vaccine works. But the effectiveness in such a study situation may differ from the actual effectiveness, if possible billions of participants are vaccinated.

Pfizer/BioNTech, Moderna and AstraZeneca/Oxford University vaccines have now been shown to be highly effective, according to the developers in the trials. Practice will have to show whether in the real world that effectiveness will indeed be so high.

If the Oxford Vaccine has a lower efficacy, why would you use it?

This vaccine was not developed by a pharmaceutical, but by a university. The scientists have been working for several years on creating a vaccine type that can easily be used for a new purpose.

“We were working on vaccines against flu, against Lassavirus and against MERS,” professor Gilbert of Oxford University said at the press conference today.

“Especially the latter was very useful, because MERS is also a coronavirus. When the reports came in January about a severe pneumonia-like condition, we were able to switch quickly.”

As soon as it was possible to create a potential vaccine against SARS-CoV-2, the University sought out a pharmaceutical company that wanted to cooperate on the terms of the University in bringing it to the market.

“We have sought a partner that fits our principles,” said professor Louise Richardson, the vice-chancellor of the University. “Who wanted to make the vaccine available worldwide and wanted to forego profits. That became AstraZeneca.”

The vaccine thus becomes available at a relatively low price and is therefore accessible to low and middle income countries. According to the BBC, The Oxford Vaccine costs less than EUR 3.50 per dose. Pfizer / BioNTech would charge around EUR 16.50 per dose and Moderna around EUR 27.50.

Are there any other benefits to this vaccine besides the price?

According to research director Sarah Gilbert, the Oxford Vaccine also prevents the spread of the virus, especially by people who have no symptoms of disease. “So our vaccine works against severe covid-19, against the milder variant of covid-19 and also seems effective in asymptomatic infections.” They saw the latter particularly in the subgroup which first received half and later a full dose of the vaccine. If this is true and sustained, that is very good news.

The vaccine can last for at least six months at a temperature between 2 and 8 degrees Celsius, in a normal refrigerator. This makes logistics a lot easier than with the Pfizer/BioNtech vaccine, which should be stored at -70 degrees Celsius and can only be kept for a few days in an ordinary refrigerator.

The Modernna vaccine must be stored and transported at -20 degrees Celsius, but it can be kept for 30 days in a normal refrigerator. The administration of the vaccines will also be easier with the Oxford Vaccine thanks to this improved shelf life.

In addition, AstraZeneca has installed a much larger production capacity than the other pharmaceutical companies. AstraZeneca will be able to produce three billion doses of the vaccine in its own factories in 2021 worldwide and will be able to deliver around 200 million doses this year.

Further, the company has concluded co-operation agreements with the largest vaccinfabrikant in the world, in India, is leading in Russia, Latin America, and Asia. Pfizer / BioNTech can produce 1.3 billion vaccines in 2021 and Moderna 500 million doses.

How long do the vaccines protect?

There’s no way to tell. The vaccines are simply too new to already have research data on the duration of the protection they provide. The adverse effects of the Oxford Vaccine were mild: headache, fatigue and injection site pain. All short-lived.