The United States is in a race against time to vaccinate as many people as possible before other potentially more worrisome variants of the coronavirus emerge, according to experts.
Vaccination efforts in the U.S. have been hamstrung by delivery issues, insufficient supply and hesitancy to get the shots. But to avert another surge of infections, hospitalizations and deaths, scientists say it may be necessary to rethink how the vaccines are rolled out to ramp up the number of shots administered and to protect against new strains of the virus.
"We really are in a race against new variants," said Wan Yang, an assistant professor of epidemiology at Columbia University's Mailman School of Public Health. "We need to prepare as much as possible before things increase to a level that puts more strain on our health care systems."
The vaccines, one made by Pfizer-BioNTech and another by Moderna, seem to be effective against a more contagious variant that was first reported in November in the United Kingdom. With a separate variant that is thought to have emerged in South Africa, however, early lab studies by Moderna showed a drop in the level of antibodies produced by the company's vaccine. Although Moderna said antibodies remained above protective levels, the development prompted the company to start upgrading its existing vaccine to make it more effective against emerging strains.
In the meantime, it is essential for states to try to vaccinate as many people as possible, said Ali Mokdad, a professor of global health at the University of Washington. That could mean thinking beyond the phased-in approach that prioritizes certain age groups and professions and, instead, offering a vaccination to anyone who wants one.
"You can save lives by targeting the vaccine to the elderly, but there will be a point in time when we have enough vaccines, where these phases for who goes first, second and third should be abolished immediately," Mokdad said.
Mokdad cautioned that the U.S. is not at that point yet, because there are still too many snags to work through in the supply and distribution of vaccines. Across the country, the rollout of vaccines has been bumpy, with some states struggling to administer all the doses they received and others being forced to cancel appointments because of dwindling supplies.
"The reason we're doing this phased approach is because there is limited supply," said Deepta Bhattacharya, an associate professor of immunobiology at the University of Arizona. "By and large, if you can fix the supply issues, you can vaccinate as many people as fast as possible."
Without a stable pipeline between manufacturing and distribution, Mokdad said, the country remains vulnerable should a new strain begin circulating that is more contagious or more deadly or that can evade the current vaccines.
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The prospect is not entirely unfounded, said Dr. Robert Califf, head of medical strategy and policy at Verily Life Sciences.
"The more infected people there are over time, the more chance the virus has to mutate," said Califf, a professor of medicine at Duke University who was commissioner of the Food and Drug Administration in the Obama administration. "If we don't quell the pandemic, there's a higher risk that one of those mutations will be able to escape the vaccine or therapeutic antibodies, or both."
That makes it all the more important to curb outbreaks — with standard mitigation measures, such as wearing masks, practicing social distancing and avoiding large or indoor gatherings — as vaccine researchers try to stay one step ahead of the evolving virus, according to experts.
"It's like a competition between the virus and science," Califf said.
But there is some cause for optimism, Bhattacharya said, pointing to signs that the Biden administration is mounting a federal response that is more coordinated than that of its predecessor. Supply issues could also be alleviated soon if other vaccines, including ones developed by Johnson & Johnson and Novavax, are authorized for use in the U.S.
"It has been frustrating," Bhattacharya said, "but I'm pretty confident that some of the bottlenecks will start to get eased."