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SARS-CoV-2 Vaccines

The greatest achievement by humanity in preventing death has been the vaccine. We have been able to save millions of lives over the years as a result. Science has risen to the challenge again. Researchers worked diligently to produce vaccines that will be the light out of the pandemic. They were able to move very quickly because they had platforms already established from the creation of other vaccines and research they have been doing on other viruses. The work they have done is public and has been reviewed by scientists and medical providers.

There are currently 3 vaccines that were granted Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) for use in protecting against SARS-CoV-2 or Covid-19. An EUA is a special designation that allows the US Food and Drug Administration (FDA) to help strengthen the country’s public health protections against chemical, biological, radiological, and nuclear threats by making medical countermeasures available for use during public health emergencies. 

The mRNA Vaccines

  • One from Moderna: A messenger RNA (mRNA) vaccine delivered as 2 doses spaced 28 days apart. The EUA was granted for people ages 18 and over.
  • One from Pfizer-BioNTech: An mRNA vaccine delivered as 2 doses spaced 21 days apart. The EUA was granted for people ages 16 and over.

An mRNA vaccine teaches our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies. That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our bodies. These vaccines do not transmit the Covid virus. No live virus is injected into the body. The mRNA is very fragile and breaks down rapidly after it is injected. It never enters our cells.

These vaccines were found to be between 94-95% effective in preventing severe disease caused by SARS-CoV-2 after the second dose. The studies were conducted using about 40,000 volunteers each. Half received the actual vaccine and half were given a placebo that does not contain vaccine. Both vaccines were found to be safe during the study period. The most common side effects were fatigue, fever, muscle aches, and headache especially after the second dose of vaccine. Neither vaccine was studied in pregnant or lactating women. It is recommended that if you are pregnant or lactating you discuss the risks/benefits of vaccination with your provider. Clinical trials in children are currently ongoing.

Risk of severe allergic reaction has been found to be extremely uncommon. If you have suffered anaphylaxis to a vaccine in the past or have a history of severe allergic reaction, please speak with your provider prior to vaccination.

The Viral Vector Vaccine

The third vaccine given an EUA is made by Johnson and Johnson. The J&J vaccine is what’s known as a non-replicating viral vector vaccine that is delivered in a common cold virus called adenovirus. This adenovirus takes a piece of genetic material from SARS-CoV-2 and transport it into cells so that cells mount an immune response. The adenovirus is deactivated so it cannot make you sick but just acts as a transport mechanism for Covid genetic material. It was found to be 66% effective in preventing moderate and severe disease in a global study and 72% effective in the United States. It is only one dose, as opposed to Pfizer and Moderna, which are two. Since it does not contain the very fragile mRNA it can be stored at regular refrigerator temperatures.

APRIL 13, 2021: The Jansen/Johnson & Johnson vaccine administration is on HOLD due to reports of a possible association with blood clots in six women.  The FDA is investigating  and will release a statement. 

April 23, 2021:  The FDA, ACIP, and the CDC after review, has re-instated the use of the J&J vaccine.  Press announcements: FDA and CDC lift recommended pause on Johnson&Johnson-Janssen-COVID-19 vaccine

What We Don’t Yet Know:

  • Does either vaccine prevent asymptomatic infection with SARS-CoV-2?
  • Can vaccinated individuals transmit virus if infected but asymptomatic?
  • How long will vaccination protection last?
  • Are the vaccines effective enough against all the SARS-CoV-2 variants that are circulating worldwide?

More clinical studies are necessary to determine the answers to these important questions.

We at Branford Pediatrics and Adolescent Medicine encourage all who are eligible to receive the vaccine do so in order to slow the spread of COVID-19.

Vaccine Eligibility in CT More Info from the CDC