Third dose vaccine With BNT162b2 and its response on Long COVID after Breakthrough infections
Authors: hoque ashraful , Rahman Marufur , Imam Hossain , Nahar Nurun , Chowdhury Forhad Uddin Hasan 
Published: January 2022

Abstract
Background: Breakthrough events are not rare after emerging of Delta variant. On the other hand, long COVID is an unsolved issue where sufferers suffer a lot. Some study has shown that COVID-19 vaccine has improved some clinical and libratory parameters in long COVID. But what will be the possible measures against long COVID after the breakthrough event is still a burning question. Method: We have observed the third dose by BNT162b2 in a small group(n=20) who were diagnosed as long COVID after breakthrough infections, in Sheikh Hasina National Institute of Burn & Plastic Surgery Institute, Dhaka, Bangladesh. CRP(C-reactive protein) and Anti S1 RBD IgG responses were measured. Result: All 20 participants in the study received both dosage of ―ChAdOx1-nCoV-19‖ in between February 2021 to April 2021 and had breakthrough infection in the same or following month which led to long COVID syndrome. They all received a third dose of ―BNT162b2‖. A before and after 3rd dose (14 days after) CRP from participants serum was measured. A Wilcoxon matched paired signed rank test revealed significant (P value <0.05) reduction of inflammatory marker (CRP) after receiving the 3rd vaccine dose. Pre and post 3rd dose quantitative anti S1-RBD IgG response was measured and compared that revealed significant boosting effect that clearly correlates with the CRP response. Conclusion: Coverage of vaccines all over the world is still not expected level to control this pandemic. WHO has not recommended the use of a third/booster Background: Breakthrough events are not rare after emerging of Delta variant. On the other hand, long COVID is an unsolved issue where sufferers suffer a lot. Some study has shown that COVID-19 vaccine has improved some clinical and libratory parameters in long COVID. But what will be the possible measures against long COVID after the breakthrough event is still a burning question. Method: We have observed the third dose by BNT162b2 in a small group(n=20) who were diagnosed as long COVID after breakthrough infections, in Sheikh Hasina National Institute of Burn & Plastic Surgery Institute, Dhaka, Bangladesh. CRP(C-reactive protein) and Anti S1 RBD IgG responses were measured. Result: All 20 participants in the study received both dosage of ―ChAdOx1-nCoV-19‖ in between February 2021 to April 2021 and had breakthrough infection in the same or following month which led to long COVID syndrome. They all received a third dose of ―BNT162b2‖. A before and after 3rd dose (14 days after) CRP from participants serum was measured. A Wilcoxon matched paired signed rank test revealed significant (P value <0.05) reduction of inflammatory marker (CRP) after receiving the 3rd vaccine dose. Pre and post 3rd dose quantitative anti S1-RBD IgG response was measured and compared that revealed significant boosting effect that clearly correlates with the CRP response. Conclusion: Coverage of vaccines all over the world is still not expected level to control this pandemic. WHO has not recommended the use of a third/booster