So where is this wave? Case numbers, at national and even state level, are not rising. Across the United States, the number of new cases reported each day has been steady for the past two weeks. Hospitalizations and deaths are still falling from their peak during the micron wave. Some states are seeing an increase in cases — particularly New York and Massachusetts — but there is still little evidence of major peaks. In Nevada, for example, while there has been a 73 percent increase in new cases in the last two weeks, the actual number of reported infections is still quite low: 171 cases per day. Except in recent weeks, the number of cases has not been so low since May 2020. None of the half of the experts I spoke to wanted to be very definitive about what was going on. There is still a possibility that the cases will increase in some places. For example, it’s too early to tell if this 73 percent increase in Nevada daily cases is a blow or the start of exponential growth. But at this point, most of them believe that the BA.2 wave may be more ripple. This has happened again. Some troubling variants came and went in the US without causing a wave nationwide: After the alpha variant was identified in late 2020, public health officials feared a new explosion would occur, but it never did. (The catastrophic winter wave of that year was mainly caused by the original virus.) “The situation is very reminiscent of the alpha wave last year, which many people worried would cause a big spring wave here in the US, but was only recorded as a blow to our fall from the winter wave,” said Spencer Fox, deputy director. of the Covid-19 Modeling Consortium of the University of Texas. Other experts have similar expectations. “I do not think BA.2 will be associated with an explosive wave similar to the one we saw before January,” said Wafaa El-Sadr, an epidemiologist at Columbia University. Justin Lesler, who helped lead the Covid-19 modeling effort at the University of North Carolina, told me the same thing: “It is unlikely that we will see in the United States something like a micron or a delta wave.” If this sounds like good news, it’s a warning. BA.2 seems unlikely to trigger a new wave of illness and turmoil so soon after Omicron wreaked havoc. But this does not mean that the country is now clear. People are taking fewer precautions than ever before, which will give the virus a chance to spread. There are individuals — the elderly, immunocompromised, children under 5 years of age who are not yet eligible for vaccination — who may have little or no immunity if infected with BA.2. And the immunity provided by the recent boost shots may not last long, according to new data. This next phase of the pandemic is not just about BA.2, Lessler said. It is “BA.2 + long masks + decreasing immunity.”
Even though BA.2 is unlikely to trigger a nationwide wave, it still carries risks
Outbreaks appear to be exacerbated during this time, as most people rely on home tests, the results of which may not be reported to their local health department. BA.2 is also more likely to cause gastrointestinal discomfort and could be misinterpreted as a stomach upset. However, hospitalizations and deaths are less likely to be lost and are still in steady decline. Sewage samples could also show large amounts of virus if cases increase, even if more traditional surveillance shows a decrease. So why might BA.2 turn out to be a little “stupid”, as Marc Johnson, who leads the Missouri Sewage Surveillance Program, described it to me? There is more immunity in the US population than ever before. About two-thirds of Americans have received two vaccines with the Covid-19 vaccine, and 30 percent have received three vaccines. The recent micron wave also spreads a lot of natural immunity, which should provide protection against its cousin. More than 30 million Covid-19 cases were reported between December 1 and March 1. Although BA.2 is more contagious than the original omicron strain, it does not appear to be able to escape the immunity provided by a previous omicron infection, experts say. Vaccines also continue to provide a strong level of protection for most people. Add it all and, as Lessler put it, BA.2 “does not have enough impetus to overcome all the extra immunity.” In some parts of the United States, where there were few public health restrictions and more relaxed behaviors that allowed the omicron to tear the population apart, there is a greater likelihood of high physical immunity to BA.2. This is one reason the United States may not repeat the UK experience with BA.2: America’s first micron wave was much worse than Britain’s, based on the number of deaths reported. But in places that until now were more alert, but now loosen the rules, larger pockets of the population may have been untouched by the micron and are therefore more prone to BA.2. “We may have these strange phenomena where the parts that let the micron get angry may be relatively protected because they had this big micron wave,” Lesler said. “But where the micron was somewhat limited, we are more likely to see a slight bump. “Less protection came from immunity, but from things they did and can stop doing.” Various vaccination rates will also continue to play a role in how different communities are doing. “There is a significant difference in vaccination rates and the like,” William Hanage, an epidemiologist at Harvard University, told me. “Therefore, I will not be surprised if we see a blow in some places that is more serious than others.” Some people will also be at greater risk than others as BA.2 spreads. Elderly people are always at higher risk for serious complications of Covid-19 and, while about 60 percent of the population over the age of 65 is boosted, new data published in the New England Journal of Medicine suggest that protection against infection provided by a booster vaccine is elusive. Immunocompromised people also tend to see less benefit from vaccines, which puts them at higher risk. The Biden government has made more people eligible for booster vaccines to reduce the risks for people over the age of 50 and with immune conditions, but the extra immunity may be short-lived. Then there are children under the age of 5, who are still not eligible for any Covid-19 vaccine. In general, they have a much lower risk of the virus than the elderly. But this does not mean that their risk is zero. In particular, children of color have a higher risk of serious illness and other rare complications, such as extreme inflammation that is sometimes associated with infection. “Uncontrolled spread means more morbidity and more chances for long-term health effects,” Arrianna Planey, a UNC health policy professor, told me. “Since there are no vaccinations for children under 5, this is particularly worrying.” Thus, Covid-19 will continue to burden, especially the most vulnerable, even when life begins to return to something almost normal. “The challenge is how to find a balance where we can all follow sensible public health measures … without undue panic,” said El-Sadr, citing vaccinations and masking, especially in busy interiors. Experts also fear that, in the long run, a small ripple instead of a huge BA.2 wave may offer a false sense of security. In a sense, we are lucky: This new variant dominates soon after an earlier version of the virus it is associated with and has not shown a strong ability to bypass existing immunity for this reason. Our fortunes can be endured – but that is not certain. At a presentation to the FDA this week, virologist Trevor Bedford presented two possible scenarios for next year. In one scenario, BA.2 remains dominant and future cases are driven by predictable factors such as seasonality and declining immunity. In this scenario, Covid-19 does not disappear, but the virus does not fly at all. But the other scenario is something similar to what happened in the first version of omicron: a “wildly deviant” recurrence of the coronavirus occurs, with a high rate of attack threatening even people who have been vaccinated or infected in the past. Bedford said in his presentation that he considered the first scenario more likely. But we have been surprised in the past.
