BERKELEY, Mo. — The St. Louis County Department of Public Health has been tracking vaccine "breakthrough" cases and wants people to be aware that, yes, it is possible to get sick from COVID-19 even if you're fully vaccinated, but it's extremely rare.
The department is monitoring for breakthrough cases in which positive testing or symptoms develop at least 14 days after the last vaccine dose, and here's the bottom line:
- The department has identified 212 breakthrough infections.
- More than 350,000 adults in St. Louis County are fully vaccinated, according to the state of Missouri.
- Even with vaccine effectiveness of 90% or higher, a small percentage of people still will get sick.
- Some evidence shows that vaccination may make illness less severe in breakthrough cases.
- Still, some of those people may be hospitalized or die from COVID-19.
Most breakthrough infections present with very minor symptoms. In 17% of the health department's cases, the person is asymptomatic and was tested because of exposure, usually to a household member with COVID-19 who was unvaccinated.
Over a third of the department's breakthrough cases involve health care workers, usually with mild symptoms. They were the first to be vaccinated in the community. There have been 13 hospitalizations, and one death has been documented.
The Centers for Disease Control and Prevention has been coordinating with state and local health departments, and it is monitoring cases similarly to St. Louis County.
These studies underline the effectiveness of COVID-19 vaccines, with much less than 1% of fully vaccinated people becoming infected. No vaccine is 100% percent effective.
St. Louis County health officials urge vaccinated residents to be cautious if they're in contact with household members who are ill with COVID-19. They should consider masking and social distancing to prevent infection, and get tested if they become symptomatic or have significant exposure.
The county health department also warns that new variants of the coronavirus are spreading in the U.S. Of the nine breakthrough cases in St. Louis County that testing has shown involve a variant, most are of the U.K. variant B1.1.7. It is the predominant variant strain in our region, representing 73% of circulating virus in the most recent data.
Getting vaccinated is vital in our community to minimize the chances of severe illness after exposure to COVID-19, but also to prevent reinfection, the health department emphasizes. There have been more than 500 cases of individuals in St. Louis County who have been re-infected with the virus (0.5% of our total number of cases). Vaccination will prevent the vast majority of these infections, particularly in the vulnerable sections of our community.