On Saturday the Star Tribune published my column on vaccines and Delta and the need for better public communication. Doug Tice, who has been exceptionally fair to me, put a nice headline on. Partly because of space, however, and partly because of concerns about whether it was too esoteric for the reading public, the first part of the column as I originally wrote it was deleted. That part dealt with the ongoing failure to give us important data that would help us better assess what is going on with the epidemic. Here is the full original column:
AT THIS MOMENT WE HAVE A CRITICAL NEED FOR BETTER DATA AND COMMUNICATION
As the epidemic takes yet another twist courtesy of Delta and vaccine effectiveness panic, the Department of Health and CDC must provide much greater transparency in data and better messaging about how vaccines work. The amount of misinformation regarding the effectiveness of the vaccines and about the Delta variant is staggering.
The DOH has in its possession or can easily obtain information which is critical to understanding the effectiveness of the vaccines. It has released some minimal information on “breakthrough” infections; those occurring in fully vaccinated persons. This data should be part of the routine information releases which feed the tables of cases, hospitalizations and deaths by date they occurred. Each of those tables should have two columns, one for vaccinated persons and one for unvaccinated ones. That will allow routine tracking of trends and will show just how effective vaccines are. People have been able to make rough estimates, but the state should provide the actual data.
The age structure of an epidemic, which is the proportion and absolute number of cases, hospitalizations and deaths occurring in various age groupings, is critical information. The state has provided this in its weekly reports, but now in addition should provide this data for the breakthrough cases as a subset. That will almost certainly show that cases and serious illness in the vaccinated are occurring in the elderly, just as you would expect and just as happened when the population was completely unvaccinated.
Last summer, when reinfections were a momentary cause of concern, the Department was providing data on those cases, which are analogous to breakthrough infections in the vaccinated. It would be very helpful to have a comparison now. What is the relative rate of reinfections in the unvaccinated compared to breakthrough cases among the vaccinated, what are the rates of serious outcomes and what is the age structure. I believe this comparison would demonstrate that vaccination works at least as well as prior infection in providing protection.
After denying during the prior course of the epidemic that it had or could produce this data, the DOH has now released some information on the proportion of hospitalizations that were actually for CV-19, as opposed to those in which the patient was hospitalized for another reason but happened to test positive for CV-19 on admission. According to an article in this paper about half of all breakthrough hospitalizations were in this category. That data needs to continue to be provided, but we should see it for the entire epidemic across the whole population so that an appropriate comparison can be made.
PCR testing has many issues, one of which is the use of “cycle number” thresholds that are too high leading to a strained relationship between test positivity and infectiousness; another is only a rough ability to provide insight into whether a person is infectious, and a third is the detection of mere fragments of virus. PCR cycle numbers do bear a relationship to viral load. The state should have been routinely sampling and providing information on the distribution of cycle numbers. It should also have been routinely culturing a sample of tests for the actual presence of viable virus. Now it is critical to do so, because that will indicate that cycle numbers are higher, and viral loads are lower, in fully vaccinated persons. Research to date has found that to be the case. People with lower viral loads are less infectious. In addition, culturing must be done on a sample of tests to identify how often people are returning positive tests that do not indicate the presence of viable virus.
As important as the release of better data is the need for more fulsome communication around vaccine expectations. The immune system generates several kinds of response. In the case of actual infection by or vaccination against a pathogen, the immune response is referred to as adaptive immunity. The body identifies the chemical sequence of portions of the virus and creates cells that are capable of recognizing those sequences if they are encountered again. We are all constantly exposed to respiratory pathogens; we breathe them in and exhale them out. CV-19 isn’t going away, we are going to have exposure to it. Calling infections in the vaccinated “breakthrough” is misleading; nothing is being broken through. Adaptive immunity is not some physical barrier; it is a rapid reaction force that leads to quick clearing of the pathogen when recognized. So people will be exposed, but will be unlikely to be truly infected or infectious.
Adaptive immunity components to a respiratory virus, including B cells that produce antibodies and T cells that orchestrate the immune response and can disable viruses, are present in the bloodstream, but more importantly in the actual upper respiratory tract. Cells referred to as memory cells are present in this location and can marshal a response to a recognized pathogen and clear it very rapidly. But given the weaknesses of PCR testing, “positives” may be found while this clearing process is occurring. Hence the need for more disclosure on PCR test results for infections in fully vaccinated persons. A too-lenient definition of fully vaccinated is also at fault, the reality is that full development of especially the memory cells may take several weeks. Breakthrough infections should therefore be reported with information on how long after the last dose the infection occurred.
The development of adaptive immunity tends to be weaker as we age and is also less potent in those who have certain health conditions or who are generally immune-compromised. This weakness includes a lesser response to vaccinations. We would therefore expect to see infections in the fully vaccinated follow the same age structure we have seen prior to the vaccination campaigns—most serious illness will be in the frail elderly and those in poor health. We are fighting a respiratory virus, these are omnipresent and mutate regularly; therefore vaccine effectiveness is generally lower than against other kinds of pathogens, as we see from both flu vaccines and RSV vaccine attempts. But these CV-19 vaccines nonetheless appear to be extremely effective, against serious illness in particular.
Finally, the hysteria about the Delta variant is unwarranted. It actually results in less serious illness and the data at this point suggests it is only slightly more transmissible. It does not affect children to any greater degree than did prior variants. The vaccines appear only slightly less efficacious against Delta.
After all this time, you would like to believe that the experts and political leaders we are supposed to rely on would have learned the importance of full transparency on needed data and on doing effective and accurate messaging to set realistic expectations on topics like vaccination and adaptive immunity. I am confident that the data will be consistent with exactly what we should expect; there will be a strong and durable adaptive immune response to CV-19 from both infection and vaccination and serious outcomes will be largely avoided, but we will see cases, especially among the elderly.