Vaccination helping to control spread of COVID-19 and needs to increase

From Washington State Department of Health

OLYMPIA – The latest COVID-19 modeling and surveillance situation report from the Washington State Department of Health (DOH) shows continued declines in disease activity, with vaccination playing a key role. To keep trends on track, we need to keep increasing vaccination and continue preventive measures like wearing masks, maintaining distance and moving gatherings outside if you’re unvaccinated.

Report findings include:

• Statewide case counts and hospital admissions continued to decline as of May 20. Case counts were either flat or declining in most counties, and 31 of 39 counties had fewer than 200 new cases per 100,000 people over the previous two weeks.
• Vaccination is protecting people from COVID-19 illness severe enough to require hospitalization. Over the two-week period ending May 9, the hospital admission rate for unvaccinated people ages 45-64 was about 21 times higher than the rate for fully vaccinated people of the same age. Among people ages 65 and older, the hospital admission rate was about 13 times higher in unvaccinated people than in those who were fully vaccinated.
• Increasing immunity from vaccination is playing an important role in reducing transmission. On May 20, the best model-based estimate of overall population immunity was 43.5%. Estimated immunity from vaccination was more than twice as high as estimated immunity from prior infection.
• While vaccination has helped reduce the spread of the virus, the level of transmission was still fairly high as of mid-May. The best estimate of the reproductive number (which tells us how many new people each COVID-19 case will infect) on May 14 was 0.95. To keep seeing case and hospital admission rates decrease, the reproductive number needs to stay well below one for a substantial amount of time.
• As of May 20, case rates were declining across all age groups except people ages 70 and older, among whom case rates have stayed mostly flat since March. Hospital admission rates followed similar trends, declining among people ages 20-69 and remaining flat but high in ages 70 and older.
• The number of total hospital beds occupied by COVID-19 patients is declining as of May 30. The number of ICU beds occupied by these patients has remained fairly flat through the end of May. Hospital occupancy continues to increase for a while even after hospital admissions flatten or decrease, because patients with COVID-19 generally stay in the hospital for several days.

“We continue to see positive trends, but a significant proportion of our population is still unvaccinated and vulnerable to COVID-19 as our state approaches full reopening,” said Acting State Health Officer Scott Lindquist, MD, MPH. “If you haven’t been vaccinated yet, now is the time to get your vaccine so you can enjoy the benefits of reopening without putting your health and your community at risk.”

DOH partners with the Institute for Disease Modeling, Fred Hutchinson Cancer Research Center, University of Washington and the Microsoft AI for Health program to develop these reports every other week. More COVID-19 data can be found on the DOH data dashboard.