Source Business Insider
What’s the difference between Pfizer and Modrena vaccine?
Recently, the U.S. Food and Drug Administration (FDA) has successively approved emergency use authorizations for Pfizer and Modrena vaccines.
Late clinical trials of both vaccines are still ongoing, which means that more results may be available and changes in understanding of the effectiveness of these vaccines.
But so far, according to trials conducted on thousands of people around the world, the two vaccines look very similar. So how to choose? Business Insider’s website recently published an article that may help people make their own judgments and choices.
It can effectively prevent symptomatic COVID-19 patients.
Pfizer vaccine has a 95% effective rate in preventing symptomatic diseases, and the trial recorded 162 cases of COVID-19 in the placebo group and 8 cases in the real vaccine.
Pfizer began counting the number of cases earlier than Modrena.
Modrena vaccine was 185 cases in the prevention of symptomatic diseases, compared with only 11 patients vaccinated.
The study had a 94.1% effectiveness 14 days after the volunteer’s second injection.
In a Pfizer study, eight of the more than 18,100 volunteers had been fully vaccinated with COVID-19, and one of them was seriously ill.
According to the final analysis of the study, three placebo recipients were also seriously ill, two of whom were hospitalized and one required intensive care.
In the Modrena study, 11 of the more than 13,900 volunteers were fully vaccinated with COVID-19, but there were no severe patients.
It is not clear whether asymptomatic infection can be prevented from spreading.
Can these vaccines completely prevent infections
Pfizer did not provide data related to asymptomatic infection, virus shedding or infectiousness. More data is needed, including data from clinical trials and data from post-authorized vaccine use, which appears to be able to stop the virus from falling off into humans and reduce asymptomatic transmission, as well as the vaccine, found in animal studies.
Modrena researchers screened volunteers for the virus before both injections. When volunteers performed intensive injections, the researchers found some positive cases in the asymptomatic population: only 14 positive cases in the vaccination group and 38 cases in the placebo group.
Although Modrena said it showed that “preventing some asymptomatic infections had begun after the first dose”, the FDA said the data was too limited to draw any conclusions.
The duration of protection of the two vaccines is unknown.
The durability of vaccine protection is one of the biggest unknowns. In both studies, volunteers were tracked for at least two months after vaccination, but outside that time frame, it is not clear how long vaccine protection will last.
No one can clearly inform whether people need to be revaccinated in months or years.
This is true of Pfizer and Modrena’s vaccines.
An analysis published in the New England Journal of Medicine on December 3 showed that volunteers who had been injected with Modrena vaccine as early as March had only slightly lower neutralization antibody levels three months after vaccination.
As research continues and volunteers follow up for a long time, researchers should be able to better understand whether or when protective measures are gone.
Both vaccines have side effects.
The vaccine has two side effects: expected and unexpected. It is expected that the immune response of the vaccine is by-product.
The body reacts to injections, leading to temporary, often mild side effects, such as fatigue, headaches, and chills.
Compared with Modrena vaccine, Pfizer vaccine trials have relatively few reports of pain, fatigue and headaches.
The most common side effects are pain at the injection site (84%), fatigue (63%), and headache (55%).
Compared with Modrena trial, severe side effects occurred less frequently after the second injection, and the highest incidence among volunteers under 55 years old: 5% showed severe fatigue, 3% had severe headache, 2% had severe chills, and 2% had aggravated muscle pain.
Nine in ten volunteers involved in the Modrena vaccine had some degree of side effects, most of which were mild or moderate.
The most common reactions are pain at the injection site (92%), fatigue (69%), headache (63%), and muscle pain (60%).
Young volunteers reported more side effects. Nearly one in five volunteers aged 18 to 64 had a severe reaction after the second intensive dose.
The most common serious side effects in this age group are fatigue (11%), muscle pain (10%), joint pain (6%), fever (2%) and chills (2%).
In this younger population, very few have also reported serious potentially life-threatening side effects.
Ten of these volunteers (less than 0.1%) had severe fevers and their temperatures exceeded 39.4 degrees Celsius.
Pfizer vaccine is effective for the elderly, while Modrena vaccine is better for preventing severe diseases.
Both vaccines are recommended for use in adults of any age.
However, these trials do not have a uniform number of people covering all ages, so it is not clear which vaccine may be the best at which age group.
Among Pfizer Vaccine volunteers, 4,294 people aged 65 or older, were vaccinated, accounting for about 21% of the vaccination group. The oldest vaccinator is 89 years old, and the average age of participants is 51.
The vaccine appears to be more effective in people under 55 years old, with an effective rate of 96%, compared with 94% in the elderly.
However, as the number of vaccinated people increases, this number may change, and the difference is not statistically significant.
Of the volunteers who were in Modrena Vaccine, 3,527 were aged 65 or older, or about 25% of the vaccination group.
The oldest vaccinated population was 95 years old, and the average age of participants was 52. The vaccine appears to be better effective among people under age 65, with an effective rate of 86.4% compared with 95.6% among young people.
But these numbers may also change as more people get vaccinated.
The side effects of the Modrena vaccine are relatively mild for older people, and the side effects of headache and fatigue tend to fall on younger vaccinators under 65.
So far, Modrena vaccine has been 100% effective in preventing severe cases, while Pfizer vaccine has a severe case.
Both vaccines focus on diversity, but mainly white people.
Pfizer and Modrena have both paid some attention to diversity in their research on the novel coronavirus vaccine, which is crucial for vaccines to be delivered to hundreds of millions of people around the world.
Pfizer vaccine has been tested in six countries: the United States, Argentina, Brazil, Turkey, Germany and South Africa. 49% of volunteers are women and 51% are men.
The majority of vaccinated persons are white, classified as follows: 55% white, 26% Latino, 10% black, 5% Asian and 4% other race.
The Modner vaccine has only been tested on volunteers in the United States.
48% of volunteers are women and 52% are men.
The majority of vaccinated persons are white, classified as follows: 64% white, 20% Latino, 10% black, 4% Asian and 4% other race.
Pregnant women and children are excluded from two vaccine trials.
Few people are excluded from vaccine trials, and many participants have previous diseases such as diabetes, hypertension, obesity, liver disease and heart disease.
However, there are also some people who have not been tested.
The Pfizer Vaccine Study excludes people under the age of 16, breastfeeding women and pregnant women, and people with severe allergic reactions to drugs.
Patients with immunocompromised function were allowed in this study, but not many. For example, only one person in the study had AIDS, but belonged to the placebo control group.
The Modrena vaccine study does not include people under the age of 18.
Mainly recruiting front-line workers, 82% of them are at “occupational risk” of COVID-19, 25% of whom are medical staff.
Pregnant women are also excluded from Modrena’s research.
Like Pfizer’s trial, the Modrena vaccine study also allows patients with immunodeficiency to participate, but not many. Similarly, only one person in Modrena’s study had AIDS and belonged to the placebo control group.
There are no child data for both vaccines, but testing is already in progress.
Children won’t get a coronavirus vaccine soon outside of clinical trials.
The FDA said it hopes that there will be enough pediatric data in 2021 to start vaccinating children in the summer.
But it depends on whether the research work is completed on time.
Pfizer began to test vaccines for children over 12 years old in October.
The FDA has authorized the Pfizer vaccine to be administered to people over 16 years old, although one case of COVID-19 occurred in the study among people aged 16 and 17.
The FDA believes that biologically, the effectiveness of inferring between the ages of 16 and 17 is similar to that of young people.
Modrena began recruiting 3,000 healthy children between the ages of 12 and 17 for vaccine trial studies from December 10, and hopes to get the results of the research in the spring of 2021.
The safety of the two vaccines will remain under supervision.
Large-scale studies of the two vaccines have not found major safety problems.
But public health regulators around the world are closely monitoring, especially as these vaccines are being rolled out to millions of people.
Some potential security issues need to be closely monitored as follows:
In Pfizer’s large-scale trials, there were a few cases of Bell paralysis, which showed facial muscle weakness, usually temporary.
Four cases were reported in the vaccination group, but no report was reported in the placebo group. After two people with allergic reactions developed non-fatal allergy symptoms after vaccination, the UK health regulators have warned anyone with a serious allergy history to food or drugs not to get the Pfizer vaccine.
Of the 30,000 people who participated in the Modner vaccine trial, four volunteers developed Bell paralysis.
Three of them were vaccinated against Modrena, and one belonged to the placebo control group.
Combined with the two trials, seven cases of Bell paralysis were found out of more than 40,000 people who were vaccinated against the test, with a probability of less than 0.1%.
This number is too small to tell whether these cases are related to vaccination.
But the FDA said that the relationship with the vaccine “can’t be ruled out” and should be closely monitored in the future.