ST. LOUIS COUNTY, Mo. — The St. Louis County Department of Public Health is warning the public about a rise in COVID-19 cases among people who are fully vaccinated, commonly known as "breakthrough cases."
The department issued public health advisories earlier this month warning residents of “significant” increases of COVID-19 cases in those who are unvaccinated and among children, who are transmitting the virus much more easily than what was documented last year. Now, the county said it's starting to see an emerging trend among those who are vaccinated.
While infection in those who are fully vaccinated is uncommon, the department said it has seen a recent increase in the number of vaccinated people who have gotten the virus.
The department’s data shows 35 residents in the county who were fully vaccinated got COVID-19 in March 2021 and that number increased to 213 in June.
5 On Your Side asked the county health department for clarification on the number, to see whether the 213 cases were cumulative for March-June or reported in June only. A health department spokesperson said their "data is not complete enough to assert that figure."
At this time, the department hasn’t identified what's behind the increase.
"We do not yet know the full significance and cause of this increase, but it is a noted trend and you may be hearing about it in your community," the public health advisory states.
5 On Your Side broke down the numbers based on what the county has reported on its online dashboard.
There are 443,792 vaccinated St. Louis County residents as of Wednesday afternoon, according to the state health department's website. The 213 breakthrough cases comes out to about a 0.05% positivity rate among the total number of vaccinated residents.
Early on, COVID-19 cases in fully vaccinated people was mainly seen in health care workers but has now shifted to the general population and older people.
The department said in many cases, a vaccinated person is exposed to someone with COVID-19 who is unvaccinated within the same household. This suggests that continuous, unmasked exposure to the virus in large amounts may strain protection that the vaccine provides.
“Think of the COVID-19 vaccine as a suit of armor that will reduce the possibility of injury from attack. It may not protect you 100% of the time if you have significant and repeated exposures to the virus. The COVID-19 vaccine is not an impenetrable shield, but it is the best tool we have to fight the virus and it is highly effective,” the department said in a news release.
The department said its data shows that those who were vaccinated were 86% less likely to get COVID-19 then those who were unvaccinated.
Health officials continue to urge all eligible residents to get vaccinated and in addition, recommend the following:
- Regardless of vaccination status, wear a face covering in indoor public places when the vaccination status of those around you is unknown.
- While getting yourself vaccinated offers protection, you are most protected if those with whom you live and spend time are also vaccinated. Support your family and friends in getting vaccinated. Even one unvaccinated person in a household or social group can put everyone at risk.
- People with risk factors for severe COVID-19 infection (older people and those with chronic medical conditions) are still most likely to have the worst outcomes from getting the infection. If you live with someone who is at high risk for complications from COVID-19, even if they are vaccinated, you are putting them at risk if you are unvaccinated. Get vaccinated to protect those you love.
- If someone in your household tests positive for COVID-19, to the extent possible, they should isolate from others in the home, regardless of the vaccination status of everyone in the home. If you are caring for someone with COVID-19, wear a mask.