Covid Vaccines Available In The USA : Pfizer V/s Moderna Covid-19 Vaccines


Covid vaccines available in the USA are Pfizer- BioNTech and Moderna covid-19 vaccines. Which vaccine is better between these two? 

After the tremendous efforts of scientists and researchers, we got the vaccines, but with the differences in the branding of vaccines, numerous controversies are going around. If we talk about the US, then Moderna and Pfizer are the two vaccines approved by the USA. 


The FDA( Food and drug administration) has approved the Pfizer covid vaccines, for emergency use. The authority declared the vaccine as a “significant milestone”  in the pandemic. Which have taken almost 2,95,000 lives in the US. 

The vaccines which show up to 95% efficacy are considered as the vaccines that are safe and effective. The first vaccination will take place in less than 24 hours, president Donald Trump said in an announcement. 

We will discuss the availability and efficacy of USA vaccines in this article. 

About Pfizer-BioNTech Corona Vaccine

The Pfizer has been approved by the Food and Drug Administration for emergency use. It has been authorized for an emergency under the authorization for emergency use, as to prevent the citizens of 16 years old or above. This was the first step to tackle the battle with pandemics and a step forward to the safety and prevention from coronavirus. 


Before saying anything about which vaccine is more effective, we need to know about the manufacturing and ingredients involved in the vaccines, which makes it different or specific. 

Ingredients involved in Pfizer

Pfizer vaccine is a messenger RNA vaccine and has both synthetic as well as chemically produced ingredients and also components produced enzymatically from naturally occurring components such as proteins. There is no live content of the virus in vaccines. Inactive ingredients include potassium chloride, monobasic potassium, sodium chloride, phosphate, dibasic sodium phosphate dihydrate, and sucrose, and some other ingredients in small amounts. 

Does Pfizer cause allergies? 

 Some severe allergies have been reported about the Pfizer vaccine, during the mass vaccination aside from clinical trials. Pfizer is reporting and monitoring all the reports of severe allergies in coordination with the health authorities. The stated information has a clear warning or precaution, that enough medical treatment should be readily available in case of any hypersensitive event following vaccine administration.  

How does the Pfizer vaccine work? 

Pfizer was the first corona vaccine that showed promising results in the latter testing procedures. 

It is a typically new type of vaccine called mRNA vaccine, that uses small fragments of genetic codes from the coronavirus to assist the body how to fight the coronavirus and enhance immunity. 

“The vaccine contains a small piece of the covid-19 virus’s mRNA that instructs cells in the body to make the virus’s distinctive ‘spike protein’, the FDA said. -(sources) 

“When a person takes this vaccine, their body produces the copies of spike protein, which does not cause infection but stimulates the immune system to learn to fight effectively and defensively, producing appropriate response against the virus. 

Also read: which Indian vaccine is better and why? 

Dose of Pfizer  

There are two doses of the Pfizer vaccine, one after the interval of 21 days of the first dose. The first dose starts to trigger your immune system, but the second dose will provide you the full results and will boost your immunity. 

About Moderna Mrna-1273 Covid-19 Vaccine 

The world health organization on immunization has provided interim recommendations for use of the Moderna mRNA vaccine against coronavirus infection in people 18 years or older.  

 A biotechnology company announced that Moderna is effective 94.5% based on the previous data.

 The results are “very impressive”, said Dr. Anthony S.Fauci, director of the National Institute of Allergy and Infectious Disease in an interview with the New York Times- (sources) 

Ingredients involved in Moderna covid-19 vaccine 

Ingredients involved in Moderna vaccines contain messenger RNA(ribonucleic acid), lipids tromethamine, tromethamine hydrochloride, sodium acetate, and acetic acid. 

Does the Moderna mRNA vaccine cause allergy? 

According to the reports of the Center for Disease Control and Prevention (CDC), Moderna’s vaccine barely causes any side effects. By January 10 about 4.04 million people were inoculated, of these only 10 developed lethal side effects called anaphylaxis. 

Some patients went to mild to severe side effects including drowsiness, nausea, vomiting, tongue swelling, and rashes over the body within a few hours of vaccination. 

How does the Moderna vaccine work?

This is also an mRNA vaccine and works on the same principle as Pfizer, that it takes some small fragments of genetic codes from the coronavirus, to recognize the immune system about kicking it. the antigen-antibody reaction takes place and it stimulates the immune system to recognize the virus on the further encounter.

The dose of Moderna mRNA covid vaccine 

SAGE recommends two doses of Moderna vaccine, 28 days apart from the first dose. The interval may be extended up to 42 days if found necessary.  

SAGE recommends that the vaccine will be observed in the first 15 minutes after the administration, and those who encountered the severe side effects won’t be eligible for the second dose.  

Pfizer V/s Moderna Covid-19 Vaccines 

Both vaccines have quite similar effectiveness according to the clinical trials in a number of people of different races and cultures. Pfizer protects 95% of people who had the covid infection. While the Moderna vaccine protects 94% of people with infection. 

Both vaccines also reduce the chances of severe illness, in a number of people, who still acquired corona infection. Nobody needed the hospitalization either during the trials. 

Neither vaccine has been tested on pregnant, breastfeeding, or taking immune-suppressing medications.


Age:- The Pfizer can be administered to 16 years or older, while the Moderna vaccine can be taken by 18 or above. Though companies are testing vaccines over 12 years or older. 

Dose interval:- The duration between the first and second doses is slightly different in the two. People taking the second dose of Pfizer need to wait for 21 days after taking the first dose. On the other hand, the duration of Moderna is 28 days. 

Storage:- Both vaccines require cold temperatures for storage, but Pfizer needs more cold conditions. The Pfizer needs to be stored at -75C for storage and shipping, still much colder than the usual storage conditions in pharmacies. Though it can be stored in a normal refrigerator for 5 days.

While Moderna requires -20C for storage and shipping, similar to the normal home fridge. It can stay well for 30 days at refrigerator temperature. 


The vaccines available in the USA are quite effective and worth administering to the patients. The Pfizer and Moderna covid-19 vaccines have almost similar features with few differences as well. When Pfizer is eligible for 16 years or older, Moderna is for 18 or above. Though the trials are happening on 12-year-olds as well. The Pfizer is 95% effective and Moderna is not less than this being the effective mRNA vaccine. How effective is Pfizer and how effective is the Moderna vaccine? this can’t be told accurately, as there have been some cases of severe side effects as well. Though those were a few cases. Most of the vaccinations don’t need any hospitalization or any special observations.  

Frequently Asked Question

How many Covid vaccines are produced daily in India?

On an account of 28.33 doses of the covid-19 vaccines produced daily in the country. And the vaccine beneficiaries are about 12 to 13 lakhs who are taking the doses per day. 

Can Covid vaccine be given to Covid patients?

According to the new guidelines by the government, vaccinations have been deferred for 3 months for those who contracted covid-19. So, wait for 3 months once you receive the covid positive test. 

Can I register for COVID-19 vaccination without Aadhaar card?

Yes, you can register yourself for vaccination on the Cowin portal without having Aadhar card by using any of these id’s:-

  • Driving license
  • Passport
  • PAN card
  • Npr smart card 
  • Voter id 

Why is steroid given to Covid patients?

Steroids are given to covid patients to treat the hyper immunity response caused due to the novel coronavirus. Most of the covid patients are dying of the infection due to this hyper immunity response that tends to cause inflammation in the lungs, and affects the other organs as well, and may cause multiple organ failure. So, steroids are given to them as an emergency medication. 

Can you and your family members register with same number for COVID-19 vaccine?

Yes, you can add 4 members with the same mobile no. Although, every person will need their documents and photo identification. One can register with any of their identity proof like Aadhar card, driving license, voter id card, or NSP smart card. 

What is black fungal infection Covid?

The black function or mucormycosis is caused by a fungus known as mucor. Many states have recently reported cases of black fungus in patients who have recovered from covid or have diabetes. According to AIIMS director Randeep Guleria, the misuse of steroids is the big issue in causing such fungal infections.  

What is dexamethasone?

Dexamethasone is the class of corticosteroids such as glucocorticoids and has been used in treating rheumatic problems like skin issues, obstructive lung diseases, and brain swelling. Thus, it has wide use due to its anti-inflammatory and immunosuppressive effects. 

How long should you take dexamethasone for COVID-19?

The use of dexamethasone should be done once regularly for only 7-10 days. As the world health organization advised not to use this medication with non-severe patients unless they are already taking it for some other condition. Steroids for a prolonged time can cause adverse effects. 

Who might benefit from dexamethasone if they have COVID-19?

Critically ill patients with covid-19 can get the benefits from dexamethasone. It was tested in the united kingdom’s clinical trial recovery over the covid-19 patients in hospitals. 

Dexamethasone is a steroid class drug used widely for a variety of issues because of its anti-inflammatory and immunosuppressive properties. 

Has the coronavirus disease been detected in blood and stool?

Yes, coronavirus disease has been detected in blood and stool samples. The covid-19 virus is responsible for causing the illness. However, the duration of shedding of coronavirus in urine is unknown.

Anjali Ved

Anjali ved is an enthusiastic writer in the health & lifestyle-related niche. She has been writing various blogs and articles on medical niches. Apart from this, she also holds a degree in medicine and an experience of two years.

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