But data in recent weeks on new variants from South Africa and Brazil has undercut that optimism, with many now believing that SARS COV two will not only remain as an endemic virus continuing to circulate in communities but will likely cause a significant burden of illness and death for years to come.

Among those changing their assumptions is Professor Chris Murray, a University of Washington disease expert whose projections on covid 19 infections and deaths are closely followed worldwide.

Murray told Reuters he quote couldn't sleep after seeing data from a recent vaccine trial in South Africa that not only showed that a rapidly spreading coronavirus variant could dampen the effective a vaccine, but that it could also evade natural immunity in people who had been previously infected.

More problematic as the South African 351 which is moderately to severely reduced vaccine efficacy about five fold or so.

The presence of variants has also prompted top US infectious disease expert Dr Anthony Fauci to urge the public to keep wearing masks even after being vaccinated on Wednesday he discussed various approaches to variants, including Madonna's clinical trial of a third booster shot, but indicated that the Holy Grail might still be some time away.

And finally, the last is one that we look to the future, namely a universal coronavirus vaccine, one that would handle variants of SARS cov two and that would hopefully be able to address other pandemic coronavirus is in the future, Murray said.

If the South African variant or similar mutants continue to spread rapidly, even with vaccines, the number of covid 19 cases resulting in hospitalization or death next winter could be four times higher than the flu.