As the Omicron BA.5 Variant Spreads, BU Infectious Diseases Expert Says It’s Time to Dial Up Protective Measures
Vaccines and booster shots remain the most important tool to stave off the pandemic, even as new variants—like BA.2.75 in India—emerge
It’s news nobody wants to hear: an even more contagious version of the COVID-19 Omicron variant is spreading, a subvariant called BA.5. In only the past couple of weeks it has become the dominant strain of COVID circulating in the United States, and has driven the rate of infections up significantly in Massachusetts.
Worldwide, the number of new coronavirus cases rose for the fifth week in a row, according to the World Health Organization, while the number of deaths remained stable. Here in Massachusetts, the amount of COVID RNA detected in wastewater jumped about 29 percent over the past two weeks, indicating that there are likely more cases to come. Even more concerning is that this variant is more apt at reinfecting people who have already had the virus.
So, if you’re someone who’s been leaving your mask behind while in crowded indoor places, like on public transport or in restaurants, Sabrina Assoumou, BU School of Medicine Louis W. Sullivan, MD, Professor of Medicine, suggests masking back up. Assoumou served on Boston Mayor Michelle Wu’s COVID-19 Advisory Committee, which helped provide guidance for the city and advised with Boston Medical Center’s patient protocols.
“It’s very important to let people know that there’s something different going on [with BA.5] and that we should be more vigilant with wearing masks,” says Assoumou, who is also an infectious diseases physician at Boston Medical Center, BU’s primary teaching hospital.
The Brink spoke with Assoumou about BA.5, what makes it more transmissible, how to navigate this phase of the pandemic, and what to expect in the fall.
With Sabrina Assoumou
The Brink: What is different about the BA.5 subvariant?
Assoumou: Whenever there’s a new subvariant, there are three things that we as doctors think about: is it more transmissible? For BA.5, the answer is yes. It feels like a broken record since Omicron, as every variant is more transmissible than the last one. The next thing is, does [this strain] cause more severe disease? That’s a little bit unclear. This subvariant behaved differently based on data from different countries, like South Africa or Portugal. It depends on how much preexisting immunity there is in a population, either from prior infection or from vaccines. And lastly, does it evade immunity? And yes, it does. Unfortunately, our current vaccines don’t work as well, but they do work very well against severe disease, hospitalization, and death. And you can increase your level of protection by getting boosted.
The Brink: What makes this variant more evasive?
Assoumou: The mutations are in the spike protein. Our vaccines are targeting the spike protein, so if you have changes in the spike, then the target just doesn’t stick as well. Still, when you’re getting vaccinated and boosted, you are increasing your level of protection. When you compare what’s happening in the hospitals and how sick people are right now, we’re not seeing what we saw in 2020. Our hospitals are not currently overwhelmed, because we have all those tools, including vaccines and outpatient treatments.
The Brink: How worried are you about BA.5’s potential to reinfect people who have already had the virus or are vaccinated?
Assoumou: It appears that we’re seeing people who had immunity through prior infection getting reinfected and reinfections in people who have been vaccinated and boosted, so that’s discouraging. If you talked to me in November 2020, I would have said, “Let’s just get through that initial primary series, and we’ll all get to the other side,” but what we’re realizing is that with waning immunity and the variants, the vaccines are not as good as protecting against infection, but they’re still really, really good at protecting from severe disease, hospitalization, and death. I don’t want people coming into my hospital really sick. With the vaccines, we’ve converted [this virus] from a severe disease to one that could be potentially managed at home. If someone tests positive who is older or has an underlying medical condition, they should call their healthcare provider as soon as possible to see if they’re eligible for outpatient treatments that are very good at preventing people from being hospitalized.
The Brink: What are some of the metrics that you pay attention to the most?
Assoumou: Wastewater data is very helpful, and the beauty of the wastewater is that it doesn’t depend on people getting tested. Right now, the amount of SARS-CoV-2 is going up [in wastewater data]. These days, so much of the testing is happening through rapid testing at home that isn’t recorded in the case counts. I’m happy people test at home to know their status so that they can isolate, but the downside is that we have not managed to capture those [results]. Some [research] estimates that cases are three times higher than the total we see, others have said seven or eight times higher. A metric I use for my family is the CDC maps that tell you the transmission levels for your area. If it’s high, then I use more of a layered approach [of protection]. I dial up or down how many layers I am using depending on transmission levels—I’m vaccinated and boosted, and right now when the wastewater data is going up, I don’t go indoors in a public setting unless I wear a high-quality mask. When transmission goes back down, I may not necessarily need to wear a mask.
The Brink: Is there a higher risk of long COVID from reinfections?
Assoumou: We don’t have good data to know. There’s a study that came out recently that seemed to say that people are more likely to get complications of long COVID with reinfections. It’s been estimated that about 10 to 30 percent of people who have an acute episode of COVID will go on to develop long COVID. Earlier on, some studies that were not as robust showed around a 50 percent reduction of long COVID in people with vaccinations, and then another study came out that said a 15 percent reduction, so the data are changing. Some recent studies seem to suggest that there’s a higher reduction in long COVID from booster shots. If you can help it, the best way to not get long COVID is to avoid COVID in the first place, and getting your booster.
The Brink: What do you see as the way out of the pandemic?
Assoumou: Our way out of this pandemic is to get as many people as possible vaccinated. The FDA recently decided that there is going to be a bivalent vaccine for the fall. This means that the vaccine will include both the ancestral strain and a more specific strain like BA.4 or BA.5. It is notable that we currently have another variant circulating in India, BA.2.75. Unfortunately, here hasn’t been the funding needed from the federal government, so it’s also unclear what the final vaccine recommendation will be, if it will only be available for high-risk people or older adults, for example.
In the long game, we really need a universal coronavirus vaccine, because we can’t keep chasing each variant. Another development underway is having an intranasal vaccine. With an intranasal vaccine, the thought is it would provide some mucosal protection and help prevent even mild upper respiratory infections [because those immune cells would be able to act quicker]. Lastly, to get out of this, we need to vaccinate the world. We really need to make sure that vaccines are accessible in lower- and middle-income countries, and that way we don’t keep chasing these subvariants.
The Brink: How can we safely enjoy the rest of the summer?
Assoumou: During the summer in Massachusetts, this is our time where we should try to do as many things as possible to make us feel alive, and when we should try engage in as many outdoor activities as possible. Outside is safer than inside. It doesn’t mean that the risk is zero, it just means that it’s safer with ventilation. If you’re in a crowded area outdoors, that increases your risk, and I would say try to minimize that as much as possible. And if you are in a crowd, that’s the time when you want to whip out your mask. If you’re indoors with a small group of people, open the windows, get some fresh air. And at a time when cases are going up, wear a high-quality mask. That’s how we all get through this. There are a lot of things that we could do so that we can feel connected.
This interview was edited for clarity and brevity.