After infection, your body produces natural immunity against the causative pathogen, be it a bacterium or virus.
Post-COVID - How safe are you after COVID?
After infection, your body produces natural immunity against the causative pathogen, be it a bacterium or virus. This persists as memory B cells, a type of white blood cell that can be quickly activated to produce antibodies against the pathogen should it infect you again and prevents subsequent infections from causing as much damage and illness. This is something we have covered before and is the underlying mechanism for vaccines and herd immunity.
We are trying to prevent people from catching COVID, as it has the potential to cause significant damage to a large number of your bodyâ€™s organ system, including long term damage to the lungs and heart that we are still trying to understand. But if youâ€™ve caught COVID, does this mean you cannot catch it again?
A preprint report from Public Health Englandâ€™s Siren study looked at 20,787 healthcare workers who were regularly tested between June and November 2020. It found 44 reinfections and 409 new infections, equating to an 83% rate of protection from reinfection. This appears to last for at least 5 months from first becoming sick. However, despite having antibodies against the virus, the viral load in these patients is still high enough to infect others.
The implications of this are clear to see. Even if you have had the virus, it is imperative that you continue to follow public health measures dictated by your countryâ€™s health department. Masks, washing hands, social distancing, and following lockdown rules depending on where you live. This is especially important when interacting with potentially vulnerable people, such as the elderly or immunocompromised.
You may still be carrying the virus asymptomatically, and in the vulnerable population being infected by COVID-19 can be potentially lethal. There is still not enough data to tell us whether this is also true for people who are vaccinated, but as rates of vaccination increase, future studies will be able to give us this information.