Difference Between AstraZeneca and Moderna Vaccines | A COVID-19 vaccine can be considered effective if it fulfills two conditions, namely preventing people from becoming infected or reducing the severity of infection if someone becomes infected. All vaccine candidates have gone through three phases of trials. A key indicator of vaccine effectiveness is a strong and long-lasting immunogenic response.
According to US Food and Drug Administration (FDA) guidelines, the COVID-19 vaccine must be at least 50% effective in placebo-controlled trials. After months of clinical trials and thanks to the efforts of scientists who have worked day and night to develop vaccines to curb the spread of the current pandemic, we now have many vaccine candidates approved for emergency use.
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What is the AstraZeneca Vaccine?
The AstraZeneca COVID-19 vaccine was developed by the University of Oxford in collaboration with AstraZeneca, a global pharmaceutical company headquartered in Wilmington, Delaware. Codenamed AZD1222, the AstraZeneca vaccine is one candidate vaccine Leading COVID-19 that has undergone extensive clinical trials in various countries including India and the United States.
The Oxford vaccine candidate has shown good results in phase I and phase II clinical trials, followed by phase III clinical trials, concluding that the vaccine offers immunity double, as a result it has been approved for emergency use. In fact, many countries have already started to inoculate the population and many are already vaccinating with the first dose.
However, many patients after receiving a dose have reported signs of blood clots, raising concerns that many countries including Germany, Italy, France, Iceland and Denmark have suspended administration of the vaccine.
The European Medicines Agency (EMA) denies any serious side effects and says the vaccine is safe to use and the long-term benefits outweigh the potential side effects. The Oxford vaccine candidate used a virus called adenovirus that came from chimpanzees and not humans. It is an attenuated virus that causes the common cold in chimpanzees and was genetically modified to allow it to grow in humans.
What is Moderna Vaccine?
The Moderna COVID-19 vaccine, codenamed mRNA-1273 is one of the first few vaccine candidates approved for emergency use by the FDA to curb the ongoing pandemic. Preliminary results show a 94.5% efficacy rate against COVID-19 infection without a severe allergic reaction.
Like the Pfizer vaccine, the Moderna vaccine is also an mRNA-based vaccine which means it uses messenger RNA to give instructions to our cells to make the spike protein of the coronavirus which the body then fights. mRNA vaccine technology is a new technology for vaccine development that offers several advantages over other vaccine technologies in terms of efficacy, stability and speed of development.
The company has synthesized part of the viral RNA and embedded this RNA in lipid nanoparticles. mRNA carries messages from viral genes to infected host cells, instructing the cells to make specific proteins. This then tells the host cell to make the spike protein present in the spike which the virus uses to enter a person’s cells.
When injected, it instructs our cells to make antibodies against this spike protein, which in turn stops the virus from entering our cells.
Difference between AstraZeneca and Moderna
The main difference between the two vaccines is how clearly they work. The AstraZeneca vaccine is a recombinant vaccine based on Viral Vector technology, while the Moderna vaccine is an mRNA vaccine which is a new technology for vaccine development.
Here are some of the differences between AstraZeneca and Moderna in terms of type, efficacy, dosage and storage.
AstraZeneca and Moderna Type Differences
The Oxford-AstraZeneca COVID-19 vaccine is a recombinant vaccine candidate that uses a replication-deficient simian adenovirus vector to deliver the recombinant SARS-CoV-2 spike protein gene. This virus is actually an attenuated virus that causes the common cold in chimpanzees and carries a small portion of the genetic material of the SARS-CoV-2 spike protein and injects it into our cells to induce an immune response.
The Moderna COVID-19 vaccine, on the other hand, is a new vaccine made from messenger RNA, called mRNA and the company has synthesized part of the viral RNA and then embeds this RNA in lipid nanoparticles. When injected, the mRNA tells the host cell how to make a spike protein so that the cell produces antibodies against this spike protein, which ultimately stops the virus from entering our cells.
Differences in Efficacy of AstraZeneca and Moderna
According to data based on clinical trials produced by the manufacturer, the Oxford-AstraZeneca COVID-19 vaccine reportedly shows an efficacy rate of nearly 62% when complete doses are placed at least one month apart. One dosing regimen showed a 90% effectiveness rate against infection when given as a half dose, followed by full doses placed one month apart.
Moderna vaccines, on the other hand, have shown an astonishing 94.5% efficacy rate, which is a staggering number compared to other vaccine candidates. The results are based on a clinical trial of more than 30,000 participants tested at multiple sites in the United States.
AstraZeneca and Moderna Dosage & Storage Differences
Moderna vaccine is given twice, with an interval of 28 days. So, if the first dose is on day 1, then the second dose is on day 29, which is an additional week compared to the AstraZeneca vaccine. Moderna vaccine bottles can be stored in the refrigerator between 36°F and 46°F for up to 30 days without puncture.
In contrast, the AstraZeneca COVID-19 vaccine can be safely stored for up to 6 months between 36°F and 46°F. Based on some new analytical data, the vaccine is believed to be more effective if there is a 12-week gap between the two doses.
While AstraZeneca and Moderna are among the leading COVID-19 vaccine candidates, the mRNA-based Moderna vaccine has a slight advantage in efficacy. Based on preliminary results, Moderna’s vaccine is believed to be about 95% effective against COVID-19 infection, a surprising number compared to AstraZeneca’s vaccine claims.