Omicron BA.2, Testing, and Epidemiology

Young people working in a office wearing masks due to COVID-19

Written by WorldClinic

February 3, 2022

Omicron BA.2

The biggest concern over the past two weeks continues to be the Omicron subvariant, BA.2. Late last week there were several news stories expressing concern that BA.2 should be considered a variant of concern because “we cannot be sure that BA.2 will not be more lethal than the original Omicron variant.” This is emblematic of the problems with much of the reporting throughout the pandemic: It is a 100% accurate statement, but without any risk information, it is entirely unhelpful. While it is true that we cannot be 100% sure that BA.2 is no more virulent, all available data says that infection caused by BA.2 is about the same as original Omicron which is generally much milder than previous strains.

What is mildly concerning about BA.2 is that it appears to be between 30 and 50% more infectious than the already very infectious original Omicron. If Omicron and BA.2 create robust immunity against various strains, then while there may be a bump in hospitalizations, which is not good, however, this very infectious combination of strains could push us to relative herd immunity much more quickly. We don’t have enough information to know the answer to this yet. One somewhat concerning note are reports from Israel today that there have been a few cases, as in single digits, of reinfection with BA.2 in people who have been recently infected with Omicron. Unfortunately, that is the sum of the available information on these potential reinfections. There is no information on co-morbidities – for example, are these patients who are relatively immunocompromised, the patient’s vaccination status, or on the severity of illness. Until we have that information, this assertion of reinfection is not helpful information, although something to keep an eye on.

Epidemiology

Turning to overall epidemiology, the Omicron wave is past or nearing the crest in most regions of the world. However, there are still several major countries with continued rapid increases in cases, and in some cases deaths. These countries include Japan, South Korea, Hong Kong, Singapore, Germany, Russia, Brazil, and Chile.    In the UK, cases continue to decrease very slowly, but hospitalizations have clearly turned down. Finally, cases are starting to rapidly decrease throughout North America, with only 2 states, South Carolina and Maine continuing to see increases and those are only in the single digits on a percentage basis. That does not mean the US is out of the woods yet as even Maryland, the state with the lowest rate in the Country is at 38 cases per 100k per day, which is about 50% greater than what is commonly considered a rate representing widespread, uncontrolled community transmission. The highest state, South Carolina, exceeds this threshold 15 times over.

As you hear these kinds of numbers, remember that you cannot compare case rates now to case rates prior to vaccination. Before vaccination, even for young people, the risk of hospitalization was there for everyone, and we all knew someone who died or at least had a very difficult course. Today, with vaccination and the lower virulence of Omicron, few people know anyone vaccinated and without significant risk factors who have had a recent difficult course. Hospitalization numbers are coming down and hospitalization risk is significant only for those people in recognized high-risk categories or the unvaccinated. Looking simply at vaccination status, the hospitalization risk for the unvaccinated is about 9 times that for vaccinated people and that’s not even including that a very high percentage of people with significant risk factors are counted in the “vaccinated” part of that ratio and, in fact, represent a significant portion of those who are vaccinated and still end up hospitalized.

When people ask why we encourage vaccination, this is the reason. While no one wants to get COVID, if they do get it, the risk of hospitalization or worse is trivially low, and the risk to those around them is similarly low. But importantly, that in no way means that we encourage mandatory vaccines. The better approach is education and information so that people can make educated decisions. The calculus on this is somewhat different in a workplace, where regulations can cause disruption of business process in the event of a super spreader event or even just a small chain of transmission. In that case, the business has a need to protect itself and prevent workplace transmission through vaccination and a selection of other risk reduction tools is important to the productivity and overall health of its workforce.

Testing

On COVID testing, with the shortage of testing capabilities spread in the country, scams surrounding testing have developed. The largest is the Chicago-based “Center for COVID Control” which used various means including “losing” test results and providing fake results in ratios that would look to regulators to represent expected patterns of results in order to mine personal data and bill for tests never conducted. The company had nearly 300 locations around the country. There are plenty of reliable test locations, but this highlights the importance of vetting both testers and individual test kits for home testing. If you are offered a test brand that you have never heard of, make sure you are getting the test through a trusted source and that test itself is listed on the FDA Emergency Use Authorization website.

Related to testing, major airlines and other travel groups are petitioning the White House to either drop the requirement for a test before entering the country or to at least set criteria for when the testing requirement will be dropped. They point out that in many ways the requirement is “prevention theater,” in that, especially internationally, it is very easy to obtain a negative test whether you are infected or not. They maintain that symptom screening is as effective and less difficult to enforce. We concur with their enforcement concerns and ease of getting around the system, but would not drop the requirement quite yet. Instead, we would leave the requirement in place for points of origin where levels are very high based on predefined criteria but then stick with this predefined level to allow the requirement to drop as levels come down around the world.

Treatments

As case rates are coming down, viral treatments, including the anti-viral Paxlovid and the monoclonal antibody treatment Sotrovimab are beginning to become easier to obtain, but only marginally so. With regard to Paxlovid, new studies this week again confirm the effectiveness of the medication against all existing strains of COVID-19. Also, the FDA last week reminded prescribers that one of the components of Paxlovid works by inhibiting a specific pathway that the body uses to clear certain medications. These medications include certain antiarrhythmics, oral anticoagulants, immunosuppressants, anticonvulsants, antineoplastics, and neuropsychiatric drugs, with some concern about effects on some lipid-lowering medications. This means that some physicians have been reluctant to prescribe Paxlovid, even when it is available. In most cases, Paxlovid can be safely used, but there may need to be adjustments in the use of the other medications. For people taking critical medications, if you need Paxlovid, ensure your physician has made the necessary checks and adjustments.

Vaccines

The main vaccination news this week is that reports indicate that the Pfizer BioNTech vaccine will likely receive emergency use authorization for children in the 6-month to 5-year age group by the end of the month. Since vaccine uptake in the 5-to-11-year age group has only been 22%, there is concern that uptake will be similarly low in this younger age group. Additionally, Pfizer has presented data that 2 shots may not provide an adequate immune response and therefore, regulators are leaning towards a three-shot series for these younger children. The need for increased vaccine doses in younger children is not uncommon, as anyone who has taken children for their childhood vaccines will attest to. This multiple shot requirement, together with the growing recognition that children without risk factors are at very low risk for a bad outcome from COVID infection may put up significant headwinds against vaccinating younger children. On the other hand, in working with various companies, it has been clear that one of the biggest obstacles many people see to getting back to in-office settings is the fear, even if the adult worker is vaccinated, that they could bring infection home to their unvaccinated children. If the final data is adequate to demonstrate that risk is low for these children, getting their children vaccinated may be useful for many families to get that peace of mind that will let them get back to more normal business and family activities, providing the benefits of socialization that many kids are missing out on for fear of infection. If families can be convinced through data and education, and not coercion, that vaccinations can enable more normal functioning, then they may very well be in these children’s best interest.

One last piece of vaccine news is that earlier this week: Novovax applied for emergency use authorization for its’ truly novel moth-based vaccine. This filing likely has minimal if any impact on US vaccine programs, but for international sales, many smaller countries use US FDA authorization as a guidepost for their own approvals, so it will make international sales easier. Additionally, it may clear a path to a COVID-Flu mixed vaccine for next season should it be determined that an additional booster going into respiratory disease season next fall would be beneficial. Right now, it’s too early to say whether it will be needed, but Novovax will be in a good position if it is.

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