FOX31 Denver

Data Desk: How does J&J vaccination pause impact herd immunity timeline

DENVER (KDVR) — All tools are needed in the grapple with COVID-19, but the Johnson & Johnson vaccines freeze – even if permanent – would not dramatically change timelines to herd immunity.

Officials including Gov. Jared Polis say the U.S. Food and Drug Administration’s and U.S. Centers for Disease Control and Prevention investigation of the Johnson & Johnson vaccine should be brief. Even if they aren’t, estimates suggest it may not have that large an impact.

Colorado has not been a heavy user of the single-shot Johnson & Johnson vaccine. Only 4% of vaccines administered in Colorado have been Johnson & Johnson to date.

If Johnson & Johnson never returned, herd immunity will only be pushed back a few days.

KDVR’s Data Desk previously ran projections for when Colorado will achieve herd immunity. These projections each assumed a 1%, 2% or 3% daily growth in the number of fully vaccinated Coloradans and the 2021 average daily increase in the number of COVID cases.

Assuming a 3% growth rate, Colorado will have achieved the lower level of herd immunity by May 13.

If we remove the expected levels of Johnson & Johnson vaccines, herd immunity happens on May 14. If we remove the levels of Johnson & Johnson vaccines used in the month of March – their highest – herd immunity happens May 15.

Removing Johnson & Johnson has the same effect on the other projections.

Assuming a 2% daily growth of fully vaccinated Coloradans, the state would reach the lower level of herd immunity by June 4. Taking out Johnson & Johnson at its historic or March rates only pushed herd immunity threshold to June 5 or June 7, respectively.

Even the longest herd immunity timeline would only be extended about a week.

Assuming only a 1% daily growth of fully vaccinated Coloradans, the state would reach the lower level of herd immunity by Aug. 6.

Taking out Johnson & Johnson at its historic or March rates would push that back to Aug. 10 and Aug. 12.