Turn on the TV and you’re likely to hear about breakthrough cases when people are discussing the COVID-19 virus, vaccines, and their doubts about both. Simply: you have a “breakthrough case” if you test positive for COVID-19 despite being fully vaccinated against the virus.
While breakthrough cases may sound concerning, health leaders from around the world aren’t surprised to see them happening. Similar to other preventive health practices (think seatbelts, handwashing, or prophylactics for STI prevention), vaccines are not a magic bullet that eliminates all risk of injury or disease, but they can reduce those risks to an acceptable level. So while medical experts still expect to see a small percentage of fully vaccinated people contract COVID-19, the data on these cases shows the vaccines significantly reduced the risk of those people becoming hospitalized or dying from the virus.
CDC data released on Sept. 10 counted an average of 10 breakthrough cases for every 100,000 fully vaccinated people, meaning that at that time, just 0.01 percent of vaccinated individuals had a breakthrough case. This data was collected between April 4 and July 19.
Many vaccine skeptics look at that 0.01% and stop listening, but it isn’t all or nothing. Instead of looking at vaccinations against the virus as a failure, health leaders are asking us to view them as an umbrella. If you’re in a little bit of rain and you have an umbrella, you stay mostly dry. But if you’re in a hurricane—umbrella or not—you’re going to get wet. That doesn’t mean your umbrella was faulty or that umbrellas in general don’t work very well. It worked until the hurricane overpowered it.
Here’s what else we know:
- Breakthrough cases aren’t limited to the SARS-CoV-2 coronavirus. Influenza vaccines reduce risk of illness by between only 40% and 60%. We see similar effects with COVID-19 vaccines, except the reduction in risk is better (due to slightly better efficacy).
- In a recent study, complete vaccination with the Pfizer (now Comirnaty) or Moderna COVID-19 vaccines were more 85% effective in health care personnel frequently exposed to the virus (including those considered ‘high-risk’).
- Because health professionals expect breakthrough infections, both mRNA COVID-19 vaccines are considered “highly effective” at preventing most infections
- Fully vaccinated people with a vaccine breakthrough infection are less likely to develop serious illness than those who are unvaccinated and get COVID-19.
- Less severe symptoms translate into a lower likelihood of being hospitalized or dying (than people not vaccinated).
- Vaccination against COVID-19 slows down the disease’s ability to create new variants.
- COVID-19 vaccines slow the presently dominant Delta variant. When fully vaccinated persons contract the Delta variant, they spread virus for a shorter time than unvaccinated persons.
While breakthrough cases do exist, misinterpretation of what they are, or what they mean can play a role in vaccine hesitancy. The fact of the matter is that vaccinating against SARS-CoV-2 does not mean you’re 100% immune but it is highly effective in preventing risky complications and remains the best way to protect yourself and those you love from the virus that causes COVID-19.