Vaccine breakthrough cases in Washington state

On April 15, 2021, The Washington State Department of Health (DOH) reported a total of 217 COVID-19 vaccine breakthrough cases among vaccinated individuals in Washington state as of April 3, 2021.

That is up from 102 since they first reported cases of breakthrough on March 30, 2021. Breakthrough cases have now been identified in 24 of Washington’s 39 counties.

Vaccine breakthrough occurs when a person tests positive for COVID-19 two weeks or more after receiving the full course of an approved COVID-19 vaccine. 

Large-scale clinical studies found that COVID-19 vaccines prevented most people from getting COVID-19 illness. 

However, the vaccines are not 100% effective. This means a very small number of fully vaccinated people will still get sick with COVID-19. Scientists note that breakthroughs are expected with any vaccine.

To date, more than 1.7 million people have been fully vaccinated in Washington state. The breakthrough cases represent a small portion, about .01 percent, of the fully vaccinated population.

DOH is investigating a total of five suspected deaths of individuals who experienced vaccine breakthrough. The people who died were between 67-94 years old and all had multiple underlying conditions. Four were residents of long-term care facilities.

In Washington state, the median age of those with confirmed vaccine breakthrough has shifted downward since the first cases were reported, with more people in the 40-59 year old demographic compared to previous weeks. Some breakthrough cases sent for sequencing showed evidence of variants.

While the majority of individuals with confirmed vaccine breakthrough experienced only mild or no symptoms, some people have been hospitalized. 

DOH is still gathering information for approximately half of the breakthrough cases. However, the agency can say that among breakthrough cases with hospitalization information available, 12% were hospitalized.

Additional investigations help us better understand clinical and outbreak information when vaccine breakthrough happens.

"Finding evidence of vaccine breakthrough cases reminds us that, even if you have been vaccinated, you still need to wear a mask, practice social distancing, and wash your hands to prevent spreading COVID-19 to others who have not been vaccinated," said Umair A. Shah, MD, MPH, Secretary of Health. 

"We encourage everyone to get vaccinated as soon as they are eligible, and encourage friends, loved ones, and co-workers to do the same."