Browse By Topic Vaccines
Delta has quickly become the dominant SARS-CoV-2 variant in over a dozen countries around the world. How contagious and deadly is this variant? Will vaccines remain protective against Delta?
What is a breakthrough infection? Why is COVID-19 vaccine breakthrough occurring and how does its frequency compare to that of other viruses and vaccines?
Do Pfizer and Moderna vaccines prevent SARS-CoV-2 infection? Can you transmit the virus after you’ve been vaccinated? How effective are mRNA vaccines in real world scenarios?