As of Monday, 32% of Americans have had at least one dose of COVID-19 and 19% are fully vaccinated. But to provide herd immunity and finally drop the transmission rate of COVID-19 to the point that the case count in the United States is seriously depressed will require something like 75% vaccination. At the current average daily rate of 2.8 million vaccinations a day, that line could be crossed in less than 50 days. If vaccination rates can average 4 million, a number reached in two recent days, it would take about 35 days to cross the line.
A good step toward that number is expected to come on Tuesday when, CNN reports, President Biden is set to move up the date on which all American adults are eligible for vaccine to April 19. This was made possible by the increasing rate of both vaccine administration and the rate at which vaccines have been shipped to states. That date will be reached despite a manufacturing error that resulted in several million doses of the Johnson & Johnson vaccine being lost.
Many states have already been accelerating their timetable as more vaccine becomes available and more vaccination sites—large and small—have appeared. However, at least five states, ranging from the low rate of disease Hawaii to currently-spiking New Jersey, still have their dates for universal eligibility set at May 1. Presumably these states are also set to announce that they are jumping forward to meet the new timeline. On the other hand, one of the lagging states is South Dakota, where Gov. Kristi Noem is equally likely to delay vaccines then brag about “owning” Biden on Fox News.
Racing the variants
For the last several weeks, the United States has been in a race between accelerating rates of vaccination and accelerating cases of COVID-19. Numbers of reported cases and deaths dropped significantly on Sunday and Monday, reaching levels not seen since the early months of the pandemic. However, past experience shows that reduced testing over holiday periods can generate artificially low values. As states report their numbers over the next two days, it should give a better view of the real situation. Going into the holiday weekend, the United States had seen three weeks of increasing rates, with several states threatening a “fourth wave.”
One of the factors driving the latest spike in cases has been the increasing prevalence of more-readily transmitted variants, like B.1.1.7, also known as the UK variant. This variant appears to spread at least 60% more easily than the variant that had previously been dominant in most of the U.S., and also has a higher rate of serious illness and death.
Additional variants that originated in South Africa and Brazil have been found in the U.S. These variants have become dominant in those areas, and contain properties that could make them slightly more evasive of vaccines as well as more capable of reinfecting past COVID-19 patients. However, neither of these variants has yet become widespread in the U.S.
Neither has a new variant from India that’s been called a “double mutant” because it has two significant changes to the spike protein that could make it both more contagious and more evasive. However, this variant is currently known only from a few cases in the U.S. and has not become prevalent in India. Rapidly growing case counts in India seem to be from the B.1.1.7 variant, not the new variant, which is found there in relatively small numbers.
As The New York Times reports, those states with increasing cases of COVID-19 seem to be the states where some of the new, more contagious variants have become dominant. Michigan has been particularly hard hit in the last few weeks, and that seems to be directly related to a high level of B.1.1.7. That variant now makes up over 70% of tested cases in the state. New Jersey is among the leaders in the number of vaccinations handed out so far, but still has seen a spike in cases with rising variants. New Jersey also has significant cases of the B.1.526 variant first found in New York City. The properties of this variant are not well understood. Likewise, California is facing another unique and poorly understood variant known as B.1.427/B.1.429.
The dampening effects of herd immunity are simply not very strong enough at this point to make the increased transmission rate of some new variants. Which makes it more important to continue wearing masks and taking precautions as the nation races toward a level of vaccination that can reverse the trends.
A POst-Easter Spike?
Easter may be about resurrection, but hopefully that doesn’t include reviving the effects seen after Thanksgiving and Christmas when rising travel and family gatherings resulted in rising cases over the following weeks. The Easter holiday is usually much less of a big get-together time, but this year with many feeling restless after a year of pandemic, and hopeful with the increasing availability of vaccines, the weekend brought new high numbers for travel. This comes after a solid month in which over a million people a day boarded planes in the U.S.
How this plays out over the next two weeks won’t be clear, but one thing to remember—people who have just received the vaccine have almost no protection during the first 8-10 days. So no one should be thinking that the vaccines are an instant panacea.