Is Pfizer COVID-19 booster shot same as the original vaccine? Read to know more

As the world continues to battle the COVID-19 pandemic, doctors have urged people to get their due vaccines. Additionally, depending on the efficacy and waning effect of the COVID vaccine doses researchers have highlighted the need for antibody amplifiers or booster shots for immunocompromised people.

In the USA, the Center for Disease Control and Prevention (CDC) recommended booster doses to enhance the efficiency of the Pfizer and Moderna vaccines from September 20.

The announcement has however flooded the internet with questions regarding the difference between the original Pfizer shots and the COVID-19 booster vaccine. People are curious about the eligibility, necessity, and performance of the booster shots. Here are all the necessary details about the Pfizer booster shots and whether it is the same as the original vaccine.

How do COVID-19 vaccines work?

As per the CDC, COVID-19 vaccines are externally administered antibodies that help develop immunity against the 2019 coronavirus. It bolsters the capacity of the inborne immune system- Macrophages, B-lymphocytes, and T-lymphocytes- to defend the body against invading germs called "antigens."

Currently, there are three types of COVID-19 vaccines available in the market that help stimulate the immune response- mRNA, Protein subunit, and vector vaccines. As CDC recommends, to be fully vaccinated, one might need two shots of the COVID-19 vaccines provided by Pfizer-BioNTech and Moderna. With Johnson and Johnson's Janssen, one shot is enough for complete protection.

However, since experts have learnt that the primary effect of the vaccines, i.e. the germ-fighting capabilities wane in about six months after taking the second shot, they recommended the use of booster shots. 

According to Hopkins Medicine, a COVID booster shot is an additional dose of a vaccine given after the protection provided by the original shot(s) starts to decrease over time. The booster is considered helpful to maintain the level of immunity against the virus. Its composition is not much different than its former doses, and in some cases, identical. In regard to the COVID-19 vaccine, the third dose of the shots are being called 'booster shots.'

As Hopkins Medicines suggests, the third dose of the mRNA COVID-19 vaccines- Pfizer and Moderna- is identical to its first two doses. It is proven to boost weakened immunity against the novel coronavirus. As per the Food and Drug Administration's (FDA) approval and CDC s recommendation, those with pre-existing medical conditions can get a third dose within 28 days after their second dose of the same brand of COVID VACCINE.

Who can receive COVID-19 booster vaccine doses?

As per the CDC bulletin, the third or booster dose will be available for people who are considered mildly or severely immunocompromised. People under specific medications as recommended by the CDC can avail the booster shot since they might suffer from a decreased immune system. Here is a list of the categories under which people in the USA are eligible for the third dose:

1. People under active cancer or tumour treatment.

2. People who underwent an organ transplant and/or are taking medicines to suppress the immune system.

3. Have had a stem cell transplant in the last two years.

4. Diagnosed with Digeorge syndrome or Wiskott-Aldrich syndrome.

5. Diagnosed with HIV or low CD4 count, including high dosage of steroids or other medications that may cause severe suppression of the immune system.

(Image: AP/Representative)