by Gertrud U. Rey It is still not entirely clear why children are less susceptible to severe COVID-19. Early hypotheses included the possibility that children may have a stronger innate immune response, which is the response that occurs upon an initial encounter with a pathogen. Results from a recent study ...

This week President Biden received the report he commissioned on the origin of SARS-CoV-2. As I predicted three months ago, nothing was learned, because to find the origin of the virus it is necessary to conduct extensive wildlife surveys. Consequently this week I would rather write about a new study ...

The US Centers for Disease Control have concluded that a third dose of COVID-19 vaccine will be needed for protection against disease, but the science says otherwise. A review of the immune responses to infection will help explain why vaccine boosters are not needed. The graph below shows the relative ...

Understanding the transmission of SARS-CoV-2 is complicated by the large numbers of presymptomatic, asymptomatic, and mildly symptomatic (PAMS) patients. The reproductive number, R0, is a measure of population-level dynamics, but it cannot provide information on infectiousness of different groups such as PAMS subjects; when peak infectiousness occurs; and the effect ...

by Gertrud U. Rey Have you ever wondered if you can "mix and match" SARS-CoV-2 vaccines? For example, would it be ok to boost a first dose of the vaccine produced by AstraZeneca with a dose of the vaccine produced by Pfizer/BioNTech? The latest science shows that such a vaccine ...