When something goes from being of interest to being a concern, it’s usually taken a turn for the worse. That would apply to a date, something in your refrigerator, and Covid-19 variants and subvariants. On May 12, the European Centre for Disease Prevention and Control (ECDC) reclassified the BA.4 and BA.5 Omicron subvariants of the Covid-19 coronavirus as variants of concern (VOC), up from being variants of interest (VOI). This shouldn’t be a cause for panic, as public health authorities will rarely say, “OK, everyone, it’s time to panic. Here’s how you should flap your arms.” However, as the label implies, these new variants should indeed be of concern and a reminder to maintain Covid-19 precautions such as wearing face masks while in indoor public areas.
This recent leveling up of BA.4 and BA.5 occurred because these two Omicron sub-lineages seem to be spreading more readily and rapidly than earlier versions of the Omicron variant, specifically BA.1 and BA.2. For example, in Portugal, the percentage of BA.5 cases relative to BA.2 ones has been increasing at a 13% rate each day. Portugal’s ditching of many Covid-19 precautions certainly hasn’t helped. This rate is expected to allow the BA.5 to go from currently being about 37% of all Covid-19 cases in Portugal to the being the dominant “alpha-dog” variant in the country by May 22, 2022.
Such a rise to dominance is essentially what’s already happened in South Africa. The BA.4 and BA.5 were initially detected in that country in January and February of 2022, respectively. Both subvariants then just kept spreading, just kept spreading with theBA.5 growing at a 12% rate over BA.2 each day. Eventually, BA.4 and BA.5 became the leading versions of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in South Africa. And as has been seen throughout much of the pandemic, what happens in South Africa rarely stays in South Africa.
With new variants continuing to emerge, you may be wondering what exactly it takes to go from being a VOI to being a VOC? Well, it’s not all about that bass. Rather, it’s all about the evidence, you know that stuff that you should actually have in hand before blurting out any claims about Covid-19. According to the ECDC, a variant becomes a VOI when “evidence is available on genomic properties, epidemiological evidence or in-vitro evidence that could imply a significant impact on transmissibility, severity and/or immunity, realistically having an impact on the epidemiological situation in the EU/EEA. However, the evidence is still preliminary or is associated with major uncertainty.” A VOI becomes a VOC when “clear evidence is available indicating a significant impact on transmissibility, severity and/or immunity that is likely to have an impact on the epidemiological situation in the EU/EEA.”
The addition of BA.4 and BA.5 essentially males the ECDC list of VOCs a “Party of Five.” This awful party includes the all-too-familiar Delta variant along with four different Omicron subvariants: BA.1, BA.2, BA.4, and BA.5. At this time, the ECDC list of VOIs is like some people’s dating calendars: completely empty.
That doesn’t mean that the VOI list will remain empty for long. The two variants designated as “variants under monitoring,” Omicron BA.3 and BA.2 + L452X, could always ascend to the VOI list. Variants under monitoring are those where “there is some indication that they could have properties similar to those of a VOC, but the evidence is weak or has not yet been assessed by ECDC.” A variant under monitoring must have been “present in at least one outbreak, detected in a community within the EU/EEA, or there must be evidence that there is community transmission of the variant elsewhere in the world.”
The ECDC lists a bunch of “de-escalated variants” as well. These aren’t variants that only affect those on escalators or who are trying to calm down a tense argument at work about whether Harry Potter should have ended up with Hermione. Instead, these are variants that fulfill at least one of three criteria: “(1) the variant is no longer circulating, (2) the variant has been circulating for a long time without any impact on the overall epidemiological situation, (3) scientific evidence demonstrates that the variant is not associated with any concerning properties.” In other words, a de-escalated variant is one that’s become yesterday’s or perhaps even yesteryear’s news.
Compared to BA.2, the BA.4 and BA.5 subvariants have several differences in their spike proteins, you know those things that stud the surface of the virus, making it look like a spiky massage ball. Think of spike proteins as tiny little virus arms and hands and the cells in your respiratory tract as hotel rooms. In order to get inside your cells to do the nasty, so to speak, the virus first uses the receptor-binding portions of its spikes to latch onto receptors on the surface of your cells just like a person uses his or her hands to grab hold of the door handle to a hotel room. The BA.4 and BA.5 subvariants do have several new amino acids with easy-to-remember names like L452R, F486V, and R493Q swapped into the receptor-binding portions of their spike proteins.
The faster spread of the BA.4 and BA.5 may be due to their ability to better evade any existing immune protection that you may have from either vaccination against Covid-19 or previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Keep in mind that the currently available Pfizer, Moderna, Johnson & Johnson, and Astra Zeneca Covid-19 vaccines prompted your cells to produce the spike proteins that were on the original version of the SARS-CoV-2, the one that had started this whole pandemic thing in 2020 and not the ones on the BA.4 and BA.5 subvariants. Plus, the protection being offered by your initial series of Covid-19 vaccinations may be waning by now. Similarly, previous infections may have prepared your immune system more for previous versions of the virus and less so for the BA.4 and BA.5 versions.
So if you are going around playing mask-less Twister with strangers thinking that you are fully protected with either vaccination or “natural immunity,” stop it. Remember that relying only on a single layer of protection can be like going to work wearing nothing but a thong. As long as the pandemic is still going on and the virus is spreading in your community, try to maintain multiple layers of protection.
Due to potential waning immunity, the ECDC is recommending that everyone who is eligible get at least one booster dose against Covid-19. They are suggesting that those 80 years and older get a second mRNA Covid-19 booster dose as well. Should the BA.4 and BA.5 subvariants spread even further they may be lowering the age threshold for this recommendation down to 60 years of age.
Despite the changes in the receptor-binding portions of the spike proteins, it’s not yet completely clear whether the BA.4 and BA.5 are inherently more transmissible and contagious than BA.2. Also, so far there isn’t any clear evidence that BA.4 and BA.5 are more likely to cause more severe Covid-19 than earlier Omicron subvariants like BA.1 and BA.2. Stay tuned as more studies are needed to learn more about BA.4 and BA.5.
Of course, the main immediate concern about BA.4 and BA. 5 is whether they will help fuel even more Covid-19 surges in Europe and around the world. The warmer and more humid weather along with movement of activities outdoors could help dampen the spread of the Covid-19 coronavirus. At the same time, people ditching Covid-19 precautions like face mask use as if they were furry boots could leave everyone more vulnerable to a surge. At this point in time, the U.S. Centers for Disease Control and Prevention (CDC) does list Omicron, including the B.1.1.529, BA.1, BA.1.1, BA.2, BA.3, BA.4 and BA.5 lineages, as a VOC. The World Health Organization (WHO), though, hasn’t yet designated BA.4 and BA.5 as VOCs, currently listing only the Delta and Omicron B.1.1.529 variants in this category. These days all of this could change in a hurry, though. While you certainly shouldn’t panic about the emergence of these new variants, it will be important for everyone to maintain Covid-19 precautions for now. However, with politicians, TV personalities, and that random dude on Facebook claiming incorrectly that the pandemic is over, a big question is whether the public will be as concerned about these new variants as they should be.
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