Scientists weigh new tactics as vaccine rollout falters | Daily News

Scientists weigh new tactics as vaccine rollout falters

The COVID-19 vaccine in the United States.
The COVID-19 vaccine in the United States.

US: Should COVID-19 boosters be delayed? Could the dose levels be reduced, and would mixing and matching shots from different makers work just as well?

These are questions now facing Governments around the world as vaccine rollout falters and the coronavirus continues to rage, spurred on by new variants that are believed to be more contagious.

British health officials set the pace, announcing they will stretch out the second dose of vaccines authorized for use there up to three months, well beyond the three or four weeks recommended.

The idea is to scale up the number of people who can be reached quickly, even if the level of individual protection falls short of what is reached with the booster.

The World Health Organization on Tuesday effectively endorsed the UK position, saying that the second Pfizer-BioNTech COVID-19 vaccine dose could, in "exceptional circumstances," be delayed a few weeks.

Authorities in England have also granted permission to give people a second shot from a different vaccine maker if the kind they got the first time has run out.

The US had set vaccinations for 20 million people as its target for December but as of January 4, it had only reached 4.5 million. Both the US and UK have covered about 1.4 percent of their populations, Europe is far behind, while Israel is out front having covered some 13.5 percent.

The Pfizer and Moderna vaccines, based on mRNA technology, reach about 95 percent efficacy on second dose, which is reserved in storage for a person after their first.

The Moderna vaccine in particular has shown high levels of protection after the first shot -- in the region of 90 percent -- but the numbers should be treated cautiously as the sample size is small.