Detailed interpretation of the article published on the US "Business Insider" website-


　　what is the difference between Pfizer and Modena vaccine

　　Recently, the U.S. Food and Drug Administration (FDA) successively approved emergency use authorizations for Pfizer and Modena vaccines.

　　Late-stage clinical trials of these two vaccines are still ongoing, which means that there may be more results and change people's understanding of the effects of these vaccines.

But so far, based on trials conducted on thousands of people around the world, the two vaccines look very similar.

How to choose?

The US "Business Insider" website recently published an article, which may help people make their own judgments and choices.

　　Can effectively prevent patients with symptomatic new coronary pneumonia

　　The Pfizer vaccine is 95% effective in preventing symptomatic diseases. The trial recorded 162 cases and 8 cases of new coronary pneumonia in the placebo group and the actual vaccinators.

Pfizer started counting the number of cases earlier than Modena.

　　There were 185 cases of the Modena vaccine in preventing symptomatic diseases, while only 11 cases were vaccinated.

In this study, the volunteers had a 94.1% effective rate 14 days after the second injection.

　　In the Pfizer study, 8 of more than 18,100 volunteers were fully vaccinated with new coronary pneumonia, and one of the infected was in serious condition.

According to the final analysis of the study, three placebo recipients were also seriously ill, two of them were hospitalized and one required intensive care.

　　In Modena's study, among more than 13,900 volunteers, 11 fully vaccinated people were infected with new coronary pneumonia, but there were no severely ill patients.

　　Whether it can prevent the spread of asymptomatic infections is unclear

　　Can these vaccines completely prevent infections including asymptomatic cases?

Scientists don't know yet.

　　Pfizer did not provide data related to asymptomatic infection, virus shedding, or infectivity.

Vaccine injections found in animal studies seem to prevent the shedding of the virus and reduce asymptomatic transmission to humans. More data is needed, including data from clinical trials and data from the use of vaccines after authorization.

　　Researchers at Modena screened volunteers for the virus before both injections.

When the volunteers were given booster injections, the researchers found some positive cases in asymptomatic people: only 14 positive cases in the vaccine-injected population and 38 cases in the placebo group.

Although Modena said this indicated that "some asymptomatic infections had been prevented after the first dose," the FDA said the data were 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 followed for at least two months after being vaccinated, but outside this time frame, the duration of vaccine protection is unclear.

Whether people need to be vaccinated again within months or years, no one can clearly tell.

　　This is true for both Pfizer and Modena vaccines.

An analysis published in the New England Journal of Medicine on December 3 showed that volunteers who received the Modena vaccine as early as March had only a slight decrease in neutralizing antibody levels 3 months after vaccination.

With the continuation of research and long-term follow-up of volunteers, researchers should be able to better understand whether or when protective measures disappear.

　　Both vaccines have side effects

　　The vaccine has two side effects: expected and unexpected.

It is expected that the vaccine will produce by-products of the immune response.

The body reacts to the injection, causing temporary, usually mild side effects such as fatigue, headaches and chills.

　　Compared with the Modena vaccine, there are relatively few reports of pain, fatigue and headaches in the Pfizer vaccine trial.

The most common side effects were pain at the injection site (84%), fatigue (63%) and headache (55%).

Compared with Modena’s trial, the frequency of severe side effects after the second injection was lower, with the highest incidence among volunteers under 55 years of age: 5% had severe fatigue, 3% had severe headache, and 2% had severe Chills, muscle pain worsened in 2%.

　　Among the volunteers who participated in the Modena vaccine injection, nine out of ten people had some degree of side effects, most of which were mild or moderate.

The most common reactions were pain at the injection site (92%), fatigue (69%), headache (63%) and muscle pain (60%).

Young volunteers reported more side effects.

Among volunteers between 18 and 64 years old, nearly one-fifth of them had severe reactions after the second booster dose.

　　The most common serious side effects in this age group are fatigue (11%), muscle pain (10%), arthralgia (6%), fever (2%) and chills (2%).

In this younger population, very few have reported side effects that may be severely life-threatening.

Ten of these volunteers (less than 0.1%) had severe fever and body temperature exceeded 39.4 degrees Celsius.

　　Pfizer vaccine is effective for the elderly, while Modena vaccine is better for preventing severe illness

　　Both vaccines are recommended for adults of any age.

However, these trials do not have a uniform number of people covering all age groups, so it is not clear which vaccine may work best at which age group.

　　Among Pfizer vaccine volunteers, 4294 people aged 65 or above have been vaccinated, accounting for about 21% of the vaccinated group.

The oldest vaccinator was 89 years old, and the average age of participants was 51 years old.

The vaccine seems to be more effective in people under 55, with an effective rate of 96%, compared with 94% in the elderly.

However, as the number of vaccinations increases, this number may change, and the difference is not statistically significant.

　　Among the volunteers of the Modena vaccine, 3,527 people aged 65 or above have been vaccinated, accounting for about 25% of the vaccinated group.

The oldest vaccinator was 95 years old, and the average age of participants was 52 years old.

The vaccine seems to be more effective in people under 65, with an effective rate of 86.4%, compared with 95.6% for young people.

But as more people are vaccinated, these numbers may also change.

The side effects of the Modena vaccine are relatively mild for the elderly. Side effects such as headaches and fatigue tend to fall on younger vaccinators under 65.

So far, the Modena vaccine is 100% effective in preventing severe cases, and Pfizer vaccine has a severe case.

　　Both vaccines focus on diversity, but are predominantly white

　　Both Pfizer and Modena paid a certain amount of attention to diversity in their new crown vaccine research, which is crucial for the vaccine that will be delivered to hundreds of millions of people around the world.

　　Pfizer vaccines have been tested in six countries: the United States, Argentina, Brazil, Turkey, Germany and South Africa.

49% of the volunteers are women and 51% are men.

Most vaccinators are white, classified as follows: 55% white, 26% Latino, 10% black, 5% Asian, and 4% other races.

　　The Modena vaccine has only been tried on volunteers in the United States.

48% of the volunteers are women and 52% are men.

Most vaccinators are white, classified as follows: 64% white, 20% Latino, 10% black, 4% Asian, and 4% other races.

　　Pregnant women and children are excluded from the two vaccine trials

　　Few people were excluded from the vaccine trial, and many participants had 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 excluded people under 16, breastfeeding and pregnant women, and people with severe allergic reactions to the drug.

The study allows patients with weakened immune function, but not many.

For example, only one person in the study has AIDS, but belongs to the placebo control group.

　　The Modena vaccine study does not include people under the age of 18.

Mainly recruit front-line workers, 82% of the people belong to the "occupational risk" group of new coronary pneumonia, of which 25% are medical staff.

Pregnant women were also excluded from Modena's study.

Like Pfizer's trial, the Modena vaccine study also allows immunocompromised patients to participate, but not many.

Similarly, only one person in Modena’s study had AIDS and also belonged to the placebo control group.

　　There are no children's data for both vaccines, but testing is already in progress

　　Outside of clinical trials, children will not get the new crown vaccine soon.

The FDA said they hope to have enough pediatric data in 2021 to start vaccinating children in the summer.

But it depends on whether the research work is completed on schedule.

　　Pfizer began vaccine trials in children over 12 years of age in October.

The FDA has authorized the Pfizer vaccine to be injected into people over 16 years old, although a case of new coronary pneumonia occurred in people aged 16 and 17 in the study.

The FDA believes that biologically speaking, the effectiveness of inferring 16 to 17 years of age is similar to that of young people.

　　Modena began to recruit 3,000 healthy children aged 12 to 17 to carry out vaccine trials from December 10, and hopes to get the results of the study in the spring of 2021.

　　The safety of the two vaccines will still be under supervision

　　Large-scale studies of the two vaccines did not find major safety issues.

However, public health regulators around the world are watching closely, especially as these vaccines are released to millions of people.

Some potential security issues that require close attention are as follows:

　　A few cases of Bell's palsy in Pfizer's large-scale trial showed weakness in facial muscles, usually temporary.

Four cases were reported in the vaccination group and no reports in the placebo group.

After two people with allergic reactions developed non-fatal allergies after being vaccinated, the British health regulator has warned anyone with a history of severe allergies to food or drugs not to get the Pfizer vaccine.

　　Among the 30,000 people who participated in the Modena vaccine trial, 4 volunteers developed Bell's palsy.

Three of them were vaccinated with Modena vaccine and one was in the placebo control group.

　　Combining the two trials, 7 cases of Bell's palsy were found among more than 40,000 people who received the trial vaccine, with a probability of less than 0.1%.

This number is too small to tell whether these cases are related to vaccination.

However, the FDA said the relationship with the vaccine "cannot be ruled out" and should be closely monitored in the future.