- It has been hypothesized that blood serum (fluid) from patients who have recovered from COVID-19 could treat infected individuals.
- Serum contains proteins called antibodies that can bind to the virus and prevent infection.
- Support this concept is a study that has shown primates who get COVID-19 infection are protected from re-infection.
- However, other research has suggested that antibodies alone cannot entirely protect from infection and may in some cases make the infection worse.
- Therefore, extreme caution will need to be taken when attempting “serum therapy.”
Lisa asked whether serum from patients who have recovered from CVID-19 could be used to treat infected individuals. It is an interesting question. Serum from recovering patients contains immune blood proteins (antibodies) that can bind to the virus spikes (above in red) and prevent the virus from infecting cells. Transferring these proteins to infected individuals who do not have immunity might therefore help clear the infection. Supporting this concept is a new article that shows animals develop protective immunity after infection. However some viruses, especially dengue virus and respiratory syncytial virus, can use antibodies to increase their ability to infect different types of cells. This is called “immune enhancement” and can worsen an infection. While trying to develop SARS coronavirus vaccines those vaccine candidates that made mainly antibodies caused immune enhancement. Dr. Fauci mentioned this as a potential problem with COVID-19 vaccine development. It also means that we will need to be very careful when trying to use serum therapy to treat coronavirus infections as it might make people worse.