"Don't panic, but breakthrough cases may be a bigger problem than you've been told," "Breakthrough COVID-19 cases expected to become more common in coming months," and "Breakthrough COVID-19 cases are rising, and experts are trying to figure out exactly what that means" are the daunting headlines we've been seeing in the news since the vaccine rollout. But what exactly is a "breakthrough" Covid case?
Define "breakthrough case."
The term breakthrough case has been around long before Covid. It refers to "an instance in which a person becomes sick with a disease despite having received the vaccine for that disease." In layman's terms, the vaccine was ineffective on that specific patient.
A breakthrough case is NOT...
To be clear, in a breakthrough case, the person who contracts the disease did NOT become infected from the vaccine. The person would have had an exposure from another infected person and the vaccine would not have done its job at building up that person's immune system against that specific virus.
Covid-19 and breakthrough cases
Awareness and use of the term breakthrough case has increased in 2021 since the vaccine rollout and the spread of the Delta Variant. In the early days of the pandemic, there were no headlines about breakthrough cases because there was no vaccine against Covid. December 2020 is a key month in this timeline: the first Covid-19 vaccine was administered and the Delta Variant was identified in India (hitting the US in March 2021). The Delta Variant spread like wildfire causing a new spike in Covid cases due to it being more contagious than previous Covid variants. This is when we start to see headlines about the vaccine's effectiveness and breakthrough cases hit the news. It is important to note here that no vaccine is 100% effective. The goal is to make cases less severe, avoid hospitalization or death, and, hopefully, prevent the spread from an infected person to an uninfected person.
What is the data on breakthrough cases?
As of September 2021, over 181 million people in the United States have been fully vaccinated against Covid-19. It can only be considered a breakthrough case if the person has been fully vaccinated. For example, if the person has only received one dose of the Moderna vaccine and got infected, they would not be considered breakthrough or if the person received all doses of Pfizer but the 14-day set in period was not over and they tested positive, it would not be considered breakthrough. Right now, only seven states are publicly reporting information on breakthrough cases: California, Louisiana, Nebraska, Oregon, South Carolina, Tennessee, and Washington, DC (click on the state name to be directed to their reports). In California, for example, the average daily Covid case rate in unvaccinated individuals is 57.41 per 100,000 versus in vaccinated individuals is 7.12 per 100,000. It is evident that the vaccine is helping prevent the spread of Covid and especially mitigate the risk of severe cases that require hospitalization or cause death. There are so many unexpected factors in this pandemic and we can only hope that the CDC will continue to diligently track vaccine effectiveness and Covid cases to release information to the public.
How can we prevent breakthrough Covid cases?
Preventative measures for both vaccinated and unvaccinated individuals will continue to be the most important effort in decreasing breakthrough cases and cases overall. Follow CDC guidelines and get tested often. Testing is the best preventative measure and the only way to find out if you have Covid or not. If you have symptoms, have been in large crowds, or have a known exposure, you should purchase self-testing kits or book a testing appointment.
