What is a breakthrough infection? Why is COVID-19 vaccine breakthrough occurring and how does its breakthrough frequency compare to that of other viruses and vaccines?
Amidst encouraging real world data about the effectiveness of COVID-19 vaccines, and the CDC’s announcement last month that fully vaccinated individuals can engage in indoor and outdoor activities without a mask, reports of fully vaccinated people becoming infected with SARS-CoV-2 have raised questions about the frequency and cause of breakthrough infection. Why are some people who are fully vaccinated, still testing positive for the virus?
TL;DW
- Unless a vaccine is 100% effective at preventing infection, a small percentage of breakthrough cases are expected and not overly concerning.
- At this time, the frequency of COVID-19 vaccine breakthrough is, very low, ~ 0.01%, which means, COVID-19 vaccines are highly effective at preventing COVID-19 particularly when it comes to severe disease.
- There are a number of reasons that breakthrough infections may occur, including a weak or ineffective immune response to vaccination, decreased immunity over time and/or evolution of the virus.
- Evidence suggests that certain mutations may be enriched in breakthrough SARS-CoV-2 infections.
- Deletions in the “NTD-antigenic supersite” are of particular interest and require further investigation.
SOURCES:
[ Ссылка ]
[ Ссылка ]
[ Ссылка ]
[ Ссылка ]
[ Ссылка ]
