More than 17.5 million doses of the Covid-19 vaccine have been administered since the first injection of Pfizer / BioNTech was administered on December 14, according to the most recent CDC data, for an average rate of about 462,000 injections per day.
Although significantly short of initial promises in general, the pace of vaccination has steadily improved over the past five weeks. The number of doses administered in the past seven days was more than 10 times greater than in the first seven days of vaccine administration in the United States. And with additional vaccines underway, as well as commitments from the new Biden administration and current manufacturers, it can continue to improve.
In fact, Dr. Anthony Fauci said that vaccine administration is likely to meet – and perhaps even exceed – President Biden’s plan.
“I feel very confident that it will not be just that, but maybe even better,” said the director of the National Institute of Allergy and Infectious Diseases at Good Morning America on Thursday.
In any case, the United States is still many months away from vaccinating enough people to end the pandemic.
Timetables to watch
The two vaccines currently authorized for emergency use in the United States – those manufactured by Pfizer / BioNTech and Moderna – require an individual to receive two doses in order to be fully vaccinated. Another vaccine under development by Johnson & Johnson would require only a single dose.
If the Pfizer / BioNTech and Moderna vaccines remain the only ones on the market, about 500 million total doses should be administered before all adults in the United States are fully vaccinated – two for each of the 250 million or more adults who live in the United States. Currently, none of the current coronavirus vaccines are authorized for children under 16 years of age.
In the past seven days, about 914,000 doses have been administered daily. If vaccination continues at the same rate, all adults in the U.S. may be fully vaccinated by the summer of 2022, according to a CNN analysis.
If vaccination reaches 1 million injections per day, in line with Biden’s promise, that schedule could increase by spring 2022.
To fully vaccinate all adults in the United States by the end of the year, the rate would have to increase to about 1.3 million doses administered per day.
Returning to normal
Although vaccination of the entire population is ideal, it is probably not necessary to initiate a return to normal.
Herd immunity – when a sufficient proportion of the population is immune to an infectious disease and spread from person to person is unlikely to happen earlier.
Estimates of the portion of the population that must be protected to reach this limit vary as more is learned about the coronavirus. Most forecasts are in the 60 to 70% range, including those cited by the World Health Organization.
But last week, Fauci indicated that the variation could be more like 70 to 85%.
“If we do that, we will develop an immunity umbrella,” he told CNBC. “This would be able to protect even the vulnerable who have not been vaccinated, or those in whom the vaccine has not been effective.”
Assuming that three-quarters of US adults must be fully vaccinated to obtain herd immunity, the US could reach that limit in February 2022 if vaccination continues at the same rate as the last seven days – about 914,000 doses administered daily, according to an analysis from CNN.
If vaccination reaches 1 million vaccines per day, collective immunity in the United States could be achieved by the end of 2021.
At a Harvard Business Review event on Tuesday, Fauci said the effects of collective immunity could begin in the fall.
“If we do this efficiently – from April, May, June, July, August – when we get to the beginning of autumn, we should have that degree of protection that I think can take us back to some form of normality,” he said .
Despite recent reports that the United States government does not have a vaccine stock reserved for second doses, as described earlier, manufacturers have committed to the availability of supplies.
“We have in hand all second doses of previous shipments to the United States. We are continually working to produce millions more each day,” Pfizer said in a statement to CNN.
Pfizer has committed to providing 200 million doses of the Covid-19 vaccine by the end of July, and Moderna said it will deliver a total of 200 million doses by June, or the end of the second quarter of the year.
Schedules for herd immunity and general vaccination coverage may also accelerate if more single-dose vaccines are authorized for use in the United States.
However, even if the United States does achieve some level of collective immunity, the situation may be different in other parts of the world.
Last week, World Health Organization chief scientist Soumya Swaminathan warned that global herd immunity should not be expected this year.