BA.2, and the next public health crisis
BALLINGER – BA.2 is the newest Omicron (COVID) subtype to gain attention, and according to the latest information from Texas DSHS, it now accounts for approximately 40% of COVID cases in our region of Texas. The other 60% of cases are due to the original Omicron, which is now known as BA.1
The same publication also noted that our region is seeing fewer COVID cases than at any time since January last year. At that time, we were in the relative lull after the initial peak and before the appearance of the Delta variant. I specify that locally I have seen more flu than COVID in the last month. I’ve said before on these pages that I think we’ve seen our last wave of pandemic COVID, but we’ll continue to see endemic or seasonal COVID, just as we’ve seen influenza since that pandemic at the turn of the last century.
What about this new variant, BA.2? Why shouldn’t we expect a new peak due to this variant?
The reason lies in understanding the cause of the previous spikes. The initial spike was because it was a new germ and no one had a well-prepared immune system to fight it. The virus replicated and invaded the tissues, especially the lung tissues, so quickly that the response mounted by the body was very strong, but delayed.
Often the response was too strong, and this accounted for a large proportion of early deaths, until we learned to give drugs to dampen the immune response in severe cases. Like all RNA viruses, this one is constantly changing. This change is the main reason many people have had COVID more than once. After a person with a normal immune system recovers from a respiratory virus, their immune system has developed an array of defenses against that virus. These defenses are usually strong enough that the person does not catch the same virus for a considerable period of time, usually a year or more.
This array of defenses will also provide some protection against related viruses, so the person may become ill with a related virus, but the body will mount an effective response more quickly than it otherwise would, and the illness will likely be mild.
After the first wave of COVID passed through our community, there was a relative lull and then we had the peak of the Delta. In a person whose body had learned to fight the COVID we had in 2020, Delta was different enough that their immune system was caught off guard. Delta was also different enough that vaccines developed in 2020 weren’t fully effective against it. In January 2022, Omicron hit our community hard, in terms of cases, because it was different enough from all previous variants that neither previous COVID infection nor COVID vaccination provided protection against infection. However, it was similar enough to previous strains that our immune systems weren’t totally caught off guard. So, in terms of total cases, Omicron passed through our community as if we had never seen a COVID virus, but in terms of severe illness, we had considerable protection.
This is a good time to point out how sophisticated the general public has become when it comes to respiratory viruses. In 2019, probably not one in 50 people would have had the slightest understanding of “herd immunity”*, and even fewer were familiar with the well-documented tendency for new respiratory viruses to be initially severe, and not terribly contagious, then to evolve to be less severe and more contagious.
This is of course due to the fact that the main determinant of the success of a virus is the number of people infected by each sick person. People who are dead or confined to a hospital bed aren’t as good at spreading the virus as people who go to work sick for two weeks and tell everyone, “It’s just allergies.”
In addition to its ability to infect people who have some immunity due to previous infection or vaccination, Omicron also exhibited these latter two characteristics – lower disease severity and higher infectivity. These are the characteristics of a virus that goes from pandemic to endemic.
BA.2 is a sub-variant of Omicron which is even more contagious than BA.1, and it is quite similar
at BA.1 the diseases are clinically indistinguishable, and hardly anyone who has had BA.1 gets BA.2. In our county and throughout Texas, we had so many people who received Omicron earlier this year that we finally, I believe, achieved herd immunity. COVID was a monumental public health crisis, a century-old pandemic and a black swan event, or so they say.
I don’t think we should take that to mean we’re immune to a short-term public health crisis. On the contrary, I think we could experience something of a similar magnitude before the end of the decade, and perhaps before the end of the year! In any case, we must prepare with this thought in mind.
This is one of the main reasons, if not the main one, that I will continue to ask representatives of all health and safety organizations in the county, as well as those interested in volunteering, to come together in the Health and Wellness Coalition. for Runnels County (HAWC4RC, for short).
Our next meeting has been moved from this week, April 7, 2022, to Thursday, April 21, 2022. We will meet in the Ballinger Home Health and Hospice conference room.
*The term herd immunity refers to the fact that protecting a population or an entire herd from an infectious disease does not require that every member of the population be immune. It is enough that a sufficient number of individuals are immunized so that each individual who falls ill transmits – on average – the disease to less than one other individual. If this condition is met, the number of infected cases will decrease over time and eventually drop to zero.