It's hard to say exactly how many breakthrough cases there are, in part because until recently the CDC was only tracking breakthrough cases that were severe enough to require hospitalization, which is extremely rare.
In Los Angeles County, a full 20% of reported cases in June were in people who are fully vaccinated. That said, those cases tended to be mild and nearly all hospitalizations and deaths are only happening in unvaccinated people. Dr. Fauci said earlier this week that Pfizer was about 95% effective and Moderna 94% effective against symptomatic COVID, with the J&J shot a bit lower at 72%. Remember, that means there might still be some percentage who test positive without having any symptoms, like we’re seeing in pro sports and the Olympics when athletes are tested regularly.
Breakthrough cases are expected even with the best vaccines - and our vaccines really are incredibly good. Long story short, a small percentage of a big number is still a big number. If 90% of people who are fully vaccinated don’t get COVID at all, that still leaves about 16 million people who might get it despite being fully vaccinated. But there’s an important difference - breakthrough cases are much more mild than cases in people who are unvaccinated. Almost no one fully vaccinated who gets COVID is being hospitalized or dying from COVID. The incredibly small number who do get it more severely even when vaccinated are elderly and have severe underlying conditions.
So even though you may be hearing a bit more about breakthrough cases, remember that they’re still a small percentage of total vaccinated people, and they’re getting much, much less sick than unvaccinated people. Our favorite quote last week was from LA County’s Public Health Director: “It wouldn’t really make sense to not use a seat belt just because it doesn’t prevent all injuries from car accidents.” Vaccines save lives and prevent the worst infections, and they’re our best line of defense against the Delta variant.
It’s better to be safe than sorry. There is a frustrating lack of data about the Delta variant because it’s so new, but doctors are reporting that sore throat, headache, and runny nose appear to be more common initial symptoms now. This is incredibly tricky, because those are also symptoms associated with allergies, wildfire smoke, and the common cold - which is circulating like crazy right now. So, is your runny nose COVID? Probably not, but it’s not out of the question by any means. It’s important to stay home if you have symptoms and monitor them carefully.
If you know someone who has COVID right now in the US, it’s almost certainly the Delta variant. Nearly 90% of all COVID cases are Delta here, so there’s little room for doubt. That’s due in part to the fact that the Delta variant is much more easily transmitted - we’re talking seconds rather than minutes of contact - so its rise to the top of the variant food chain happened quickly.