How worried should vaccinated people be of contracting Covid-19? If you’re vaccinated, are you still able to transmit coronavirus to others, such as young children too young to get the vaccine themselves? Does the more transmissible Delta variant change the equation, and what precautions should vaccinated people still be taking?
That means breakthrough infections — or infections in people who are fully vaccinated — can and do happen.
CNN: Does it matter if you’re in a community with a lot of infection? Are you more likely to get a breakthrough infection?
Wen: Yes, and that’s why it matters what’s going on around you even if you are fully vaccinated. Risk is additive. The vaccine protects you well, but if you are constantly exposed to people who are carrying coronavirus, at some point you could have a breakthrough infection.
I’ve used the analogy before of a raincoat. The vaccine is an excellent raincoat. If you’re in the occasional drizzle, you’ll probably be fine. But if you’re going from thunderstorm to thunderstorm, at some point, you could get wet.
This is also why we have to see vaccination as not just an individual choice. Even if you’re vaccinated yourself, it matters if others around you are vaccinated, too.
CNN: Do we know how common breakthrough infections are or whether people who are vaccinated but get infected are able to transmit to others?
Other research finds that the unvaccinated who are infected with the Delta variant carry 1,000 times the amount of virus than people with the original variant. That calls into question what happens if someone is vaccinated but infected with the Delta variant. We just don’t know, at this point, how likely it is for a vaccinated person with a breakthrough infection due to the Delta variant to be contagious to others.
CNN: Do the unknowns around the Delta variant change your recommendations for vaccinated people interacting with others?
Wen: I would use an abundance of caution until we have more data. A vaccinated person around other fully vaccinated people is probably pretty safe and would not need precautions like masking and distancing. On the other hand, a vaccinated person who is exposed constantly to unvaccinated people, in crowded, indoor settings where no one is wearing masks, could become infected themselves. And even if they don’t have symptoms, there is definitely the possibility that they could carry the virus and infect others.
Until we know more about whether those vaccinated but contract the Delta variant could transmit it to others, I would urge people to be cautious if they live at home with unvaccinated or immunocompromised family members. They should consider wearing masks in indoor spaces like grocery stores and trying to avoid high-risk settings like crowded bars where others around them are unmasked and have unknown vaccination status.
CNN: To be clear, you would still recommend the vaccines?
Wen: Absolutely. The most important thing the Covid-19 vaccines do is to protect against hospitalization and death. They have proven to be remarkably effective at this, even with the Delta variant. Breakthrough infections are to be expected, and the more infections occur among the unvaccinated, the more infections there will be among the vaccinated.
The key to stopping the pandemic is for us to reach a high enough level of immunity that the virus has nowhere else to go. We can get there — but all of us have to do our part and get vaccinated. Vaccination protects the individual, and it protects others around us, too.