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57/M completed Pfizer COVID vaccine 4 weeks ago. He now goes to a commercial lab to get serologic COVID testing (test detects nucleocapsid IgG). His test comes back positive. He does not have symptoms. Assuming that this is not false positive, what might this test indicate?
1/16
Answer: Past COVID infection
At present, the CDC does not recommend antibody testing to assess for immunity to COVID-19 following mRNA COVID-19 vaccination or to assess the need for vaccination in an unvaccinated person.
@ID_fellows @NNolanMD @TxID_Edu @swinndong
Answer: Past COVID infection
At present, the CDC does not recommend antibody testing to assess for immunity to COVID-19 following mRNA COVID-19 vaccination or to assess the need for vaccination in an unvaccinated person.
@ID_fellows @NNolanMD @TxID_Edu @swinndong
2/16
Currently available COVID antibody tests detect IgG/IgM against either the spike or nucleocapsid protein. The Pfizer vaccine is an mRNA vaccine that encodes for the S protein. Hence, it is not expected to elicit antibodies against the nucleocapsid protein.
Currently available COVID antibody tests detect IgG/IgM against either the spike or nucleocapsid protein. The Pfizer vaccine is an mRNA vaccine that encodes for the S protein. Hence, it is not expected to elicit antibodies against the nucleocapsid protein.
3/16
A positive anti-nucleocapsid antibody test after the Pfizer mRNA vaccine may indicate past infection while a positive anti-spike antibody may indicate either prior infection or evidence of vaccination. http://bit.ly/3iHhy1S
A positive anti-nucleocapsid antibody test after the Pfizer mRNA vaccine may indicate past infection while a positive anti-spike antibody may indicate either prior infection or evidence of vaccination. http://bit.ly/3iHhy1S
4/16
๐๐ค๐ฉ๐๐จ ๐ค๐ฃ ๐พ๐๐๐๐ฟ ๐ซ๐๐๐๐๐ฃ๐
Vaccines are designed to simulate initial โinfectionโ that primes the immune system. Incites both antibody and cellular immune responses, play a role in protection against future infection
@MedTweetorials
http://bit.ly/3r0npT5
๐๐ค๐ฉ๐๐จ ๐ค๐ฃ ๐พ๐๐๐๐ฟ ๐ซ๐๐๐๐๐ฃ๐
Vaccines are designed to simulate initial โinfectionโ that primes the immune system. Incites both antibody and cellular immune responses, play a role in protection against future infection
@MedTweetorials http://bit.ly/3r0npT5
5/16
Antibody response: immediate production from short-lived plasma cells in lymphoid organs and low level antibody production from long-lived plasma cells in the bone marrow. Memory B cells mount an accelerated and more robust antibody response to repeat infection.
Antibody response: immediate production from short-lived plasma cells in lymphoid organs and low level antibody production from long-lived plasma cells in the bone marrow. Memory B cells mount an accelerated and more robust antibody response to repeat infection.
6/16
Vaccine types, examples:
Whole pathogen (inactivated, live attenuated)
Subunit (only part of the pathogen, important to know what part elicits protective immunity) 
vectored vaccines (engineered viral vector expresses viral protein), nucleic acid (DNA, RNA)
Vaccine types, examples:
Whole pathogen (inactivated, live attenuated)Subunit (only part of the pathogen, important to know what part elicits protective immunity) vectored vaccines (engineered viral vector expresses viral protein), nucleic acid (DNA, RNA)
7/16
Some vaccines require an adjuvant to trigger the innate immune system to elicit more robust immune response.
@RosenelliEM @gayathri25788 @Jncherabie @PBMazi @LeMiguelChavez @LParraRod @JonathanRyderMD @k_vaishnani
Some vaccines require an adjuvant to trigger the innate immune system to elicit more robust immune response.
@RosenelliEM @gayathri25788 @Jncherabie @PBMazi @LeMiguelChavez @LParraRod @JonathanRyderMD @k_vaishnani
8/16
Pfizer and Moderna COVID vaccines are mRNA vaccines. How do they work? See https://bit.ly/3ofpTuX
mRNA encodes for the spike protein
mRNA is unstable (need to freeze)
Lipid coating allows cell entry
mRNA is immediately degraded, does not incorporate to DNA
Pfizer and Moderna COVID vaccines are mRNA vaccines. How do they work? See
https://bit.ly/3ofpTuX mRNA encodes for the spike proteinmRNA is unstable (need to freeze)Lipid coating allows cell entrymRNA is immediately degraded, does not incorporate to DNA
9/16
mRNA vaccines are easier and quicker to make (egg and cell-free). Rapid scalable production possible. Prior studies on SARS-CoV-1 & MERS accelerated COVID vaccine development. Because we are in a pandemic, cases accrued faster and hence, vaccine trials finished quicker.
mRNA vaccines are easier and quicker to make (egg and cell-free). Rapid scalable production possible. Prior studies on SARS-CoV-1 & MERS accelerated COVID vaccine development. Because we are in a pandemic, cases accrued faster and hence, vaccine trials finished quicker.
10/16
Why use mRNA of the spike protein? Neutralizing antibodies triggered by the spike protein (specifically against the receptor binding domain, RBD) is most correlated with protective response (see). https://www.nature.com/articles/s41586-020-2798-3
Why use mRNA of the spike protein? Neutralizing antibodies triggered by the spike protein (specifically against the receptor binding domain, RBD) is most correlated with protective response (see
). https://www.nature.com/articles/s41586-020-2798-3
11/16
The table below summarizes the Pfizer, Moderna, and AstraZeneca COVID vaccines:
The table below summarizes the Pfizer, Moderna, and AstraZeneca COVID vaccines:
12/16
AstraZenecaโs adenovirus vectors is engineered so that it does not replicate inside the cell. The use of chimpanzee adenovirus avoids the threat of neutralization from pre-existing human vector immunity that can make the vaccine less effective.
AstraZenecaโs adenovirus vectors is engineered so that it does not replicate inside the cell. The use of chimpanzee adenovirus avoids the threat of neutralization from pre-existing human vector immunity that can make the vaccine less effective.
13/16
Recent study shows that antibodies produced by the Pfizer vaccine effectively neutralize the new B.1.1.7 SARS-CoV2 variant. http://bit.ly/39cTQra Variant consists of several mutations (including mutations in the RBD), that make the virus 50-75% more transmissible.
Recent study shows that antibodies produced by the Pfizer vaccine effectively neutralize the new B.1.1.7 SARS-CoV2 variant. http://bit.ly/39cTQra Variant consists of several mutations (including mutations in the RBD), that make the virus 50-75% more transmissible.
14/16
Another study shows that antibodies produced by the Moderna vaccine demonstrate full neutralization of B.1.1.7 SARS-CoV2 variant and a reduced but still significant neutralization against the B.1.135 SARS-CoV2 variant http://bit.ly/3pxmWHi
Another study shows that antibodies produced by the Moderna vaccine demonstrate full neutralization of B.1.1.7 SARS-CoV2 variant and a reduced but still significant neutralization against the B.1.135 SARS-CoV2 variant http://bit.ly/3pxmWHi
15/16
I always go back to @PaulSaxMD's COVID vaccine FAQs for more information https://www.nejm.org/covid-vaccine/faq. Highly recommended if you have not read it yet!
I always go back to @PaulSaxMD's COVID vaccine FAQs for more information https://www.nejm.org/covid-vaccine/faq. Highly recommended if you have not read it yet!
16/16
With the fast pace of COVID research, how do you keep up? What resources do you recommend to get the most reliable and updated research/news on COVID (pre-prints included)? @PaulSaxMD @CarlosdelRio7 @FungalDoc @Cortes_Penfield @TMcCarty2010 @DocWoc71 @Vaccinologist
With the fast pace of COVID research, how do you keep up? What resources do you recommend to get the most reliable and updated research/news on COVID (pre-prints included)? @PaulSaxMD @CarlosdelRio7 @FungalDoc @Cortes_Penfield @TMcCarty2010 @DocWoc71 @Vaccinologist
