The vaccine against SARS-COV-2, developed by Oxford University and pharmaceutical company AstraZeneca, appears to be making a major contribution to the fight against coronapandemic. Although its claimed efficacy is slightly lower by 90 percent than the 95 percent effectiveness claimed by Pfizer/BionTech and Moderna, but there are many advantages. The main questions about the vaccines against SARS-COV-2:
How certain is it that the three vaccines live up to their claimed efficacy in practice?
That is not yet to be said with certainty. What we know about their effectiveness is based on press releases. None of the three vaccines are the research data already available for peer review.
PFIZER/BionTech is about final research results and a claimed efficacy of 95 percent. Moderna and the Oxford vaccine are preliminary results from 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 participants, 2,741 received half a dose of the vaccine first and at least a month later a full dose. In that group, according to the makers, the vaccine had an efficacy of 90 percent.
The remaining nearly 8,900 subjects received two full doses with at least a month in between. In that group, the efficacy of the vaccine was 60 percent. On average, over the entire study group and the two different doses combined, this yielded an efficacy of 70 percent. So it seems logical that the vaccine should be used at 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 research data available for review today or tomorrow.
Vaccines are tested in large, strictly controlled studies. Is there a guarantee that the results will turn out the same in practice?
The efficacy of a vaccine is established in a large trial involving several tens of thousands of participants. Such a study shows how well a candidate vaccine works. However, the efficacy in such a study situation may differ from the actual efficacy, if possible billions of participants are vaccinated.
The vaccines from PFIZER/BionTech, Moderna and AstraZeneca/Oxford University have now demonstrated high efficacy 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 use it?
This vaccine was not developed by a pharmaceutical, but by a university. The scientists have been working for several years to create a vaccine type that can be easily used for a new purpose.
“ We were working on vaccines against the flu, against the Lassa virus and against MERS,” Professor Gilbert of the University of Oxford said this today at the press conference. “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.”
Once it succeeded in creating a potential vaccine against SARS-COV-2, the university sought a pharmaceutical company that wanted to participate in marketing on the terms of the university.
“ We have sought a partner that fits our principles,” said Professor Louise Richardson, the university‘s vice-chancellor. “Who wanted to make the vaccine available worldwide and to refrain from profits. That has become AstraZeneca.”
The vaccine thus becomes available at a relatively low price and therefore becomes accessible to low-income and middle-income countries. According to the BBC, the Oxford vaccine costs less than €3.50 per dose. Pfizer/Biontech would charge about 16.50 euros per dose and Moderna about 27.50 euros.
Are there any other benefits in addition to the price of this vaccine?
According to research leader 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 appears to be effective in asymptomatic infections.” The latter was mainly seen in the subgroup which first received a half and later a full dose of the vaccine. “If this is true and holds up, then that is very good news”, reacts RIVM immunologist Cécile van Els.
The vaccine has a shelf life of at least six months at a temperature between 2 and 8 degrees Celsius, in a regular refrigerator. This makes logistics a lot easier than with the PFIZER/Biontech vaccine, which is available at -70 degrees Celsiusshould be stored and kept in a regular refrigerator for only a few days.
Moderna vaccine should be stored and transported at -20 degrees Celsius, but can be stored for up to 30 days in a normal refrigerator. Thanks to this better shelf life, the administration of the vaccines is also easier with the Oxford vaccine.
In addition, AstraZeneca has built up a much larger production capacity than the other pharmaceuticals. AstraZeneca will be able to produce three billion doses of the vaccine in its own factories worldwide by 2021 and deliver some 200 million doses this year.
In addition, the company has already concluded cooperation agreements with the world’s largest vaccine manufacturer in India and major manufacturers in Russia, Latin America and Asia. PFIZER/BionTech can produce 1.3 billion vaccines by 2021 and Moderna 500 million doses.
What does this mean for us in the Netherlands?
The Netherlands can claim 11.7 to 15.6 million doses of the Oxford vaccine through the central European procurement. It is not to say when exactly they will be available and who will be vaccinated with it.
The much simpler logistics around the Oxford vaccine probably makes this vaccine more suitable for vaccinating elderly and vulnerable groups. The vaccine can be easily brought to the people. But the researchers can not yet say how effective this vaccine is precisely in the elderly. There are still insufficient data available on this. However, according to research leader Pollard, elderly people seem to tolerate the vaccine better and therefore suffer less from (minor) side effects.
How long do the vaccines provide protection?
That, too, is not to be said. The vaccines are simply too new to already have research data on the duration of the protection they offer. The side effects of the Oxford vaccine were mild: headache, fatigue and pain at the puncture site. All short-term.