As Jon Bon Jovi once sang, “We’re halfway there.” Maybe.
That’s the opinion of health analysts from Columbia Threadneedle Investments, who in a report yesterday said the U.S. is halfway to herd immunity from the coronavirus strains behind the Covid-19 pandemic.
The report, authored by Columbia Threadneedle analyst Kosta Kleyman, who also holds doctor of pharmacy credentials, predicts that full herd immunity will be achieved by the end of the second quarter.
That opinion jibes with a Wall Street Journal editorial penned by Marty Makary, a Johns Hopkins School of Medicine professor, which predicted that the U.S. would achieve herd immunity by the end of April.
Columbia Threadneedle’s authors considered both the number of vaccinations and the number of people who have recovered from infection in reaching the conclusion that the country is halfway to herd immunity, estimating that by the end of the first quarter, more than 150 million Americans will be immunized in one way or another from the virus.
“In early February, we surpassed the threshold in which we had more vaccinations in arms than we had cumulative cases of Covid-19 since the beginning of the pandemic,” Gene Tannuzzo, Columbia Threadneedle’s deputy global head of fixed income, said today. “There has been a substantial growth in vaccinations, and additional vaccines will expand upon that. We could have as many as 12 approved vaccines by the end of the calendar year.”
Sill, Tannuzzo agreed that his firm’s health-care team was “pretty optimistic.”
If only vaccinations were considered, Columbia Threadneedle believes herd immunity would be reached in the third quarter of this year.
The report’s author cautions that the herd immunity could shift if new variants of Covid-19 cannot be neutralized by vaccines.
Public health officials have disputed optimistic predictions about herd immunity. In recent appearances, Biden administration chief medical advisor Anthony Fauci has been cautiously optimistic that an accelerated vaccine rollout could lead to herd immunity by this autumn and that additional pandemic restrictions could “soon” be lifted by federal, state and local governments. His comments are based on an assumption that herd immunity will be achieved when 75% to 85% of the population is immune from the virus.
However, the CDC now says that more than 85% of the population need to be immune for herd immunity to be achieved, because of the new, more contagious strains of Covid-19.
Herd immunity remains a moving target, not just because of the virus’s tendency to mutate, but also because of other unknown variables. Scientists, for example, don't know exactly how long immunity persists in those who have already been infected. Also unknown is the true number of people who have been infected with the virus since a significant proportion of the infected never develop noticeable Covid-19 symptoms.