I had high hopes that the relative lull in covid disease would allow me to focus on other topics in this blog, but my wishes took a setback this past week mostly due to FDA and ACIP weighing in on simpler covid vaccine recommendations. While it is true they are simpler, as usual there is much complexity in the details.
The New Covid Vaccine Guidance
I was wondering what was taking so long for the FDA to update recommendations particularly for spring boosters for "elderly" (how I hate this word!) and immunocompromised individuals. Most of those individuals are several months past their last vaccine doses, and most studies show significant waning of protection after about 3 months. Well, it turns out they may have been waiting for the next regularly scheduled meeting of the ACIP on April 19, because they released their simplified authorization for bivalent vaccines on April 18. Both agencies recognize the need for simplicity if we are to see any improvement in the horrific vaccination rates in our country.
Still, lots of questions remain. I tuned in to the ACIP meeting, let's look at some highlights of their presentation.
To summarize a large amount of data, vaccine safety signals continue to be very encouraging. Separately, a new publication in Pediatrics showed a lower rate of vaccine-associated myocarditis in adolescents than had been reported previously, using data from the VAERs system.
No matter what angle you use to look at the data, the benefits of vaccination clearly outweigh risks even in the present day where most of the US population have some degree of immunity from prior infection, vaccination, or both. Here are the latest pediatric antibody data:
Looking and listening to the early presentations, I was most struck at the very effective safety tracking systems in place, composed of both old and new methods of safety assessment.
It's important to recognize that each of these systems involves different methodologies and looks at different aspects of safety. I was eligible for and received my second bivalent booster last Friday. (I should note, I'm considered "elderly" in the US in terms of this bivalent booster, but not in the UK where apparently age 75 is elderly and I couldn't have received a booster!) After my injection, I decided to look into v-safe again. I'm glad to say that v-safe is still operational and thus I was able to report on my symptoms, which were none. Those of you who have used v-safe in the past, as I have done for all 6 of my own covid vaccines, know that it asks about specific, common, side effects. It's great to monitor those rates, but it isn't a system that is designed to catch rare side effects of the vaccine. Other systems do that quite well, however, though still tough because we're talking about such extremely rare events that may occur at similar rates in the general/unvaccinated population.
Dr. Ruth Link-Geddes presented data on vaccine effectiveness against symptomatic infection in young children, collected through the ICATT (Increasing Community Access to Testing) system. VE is a difficult and somewhat moving target since vaccine uptake is so low in this population, it might vary with brand of vaccine and time since last vaccination, and, as usual, the variants are changing. As you can see, the data are very current.
Note that the Pfizer primary series requires 3 doses versus 2 for Moderna, and the system had too few children who received 3 Pfizer doses to break down VE further to give an estimate of how/when protection wanes.
A nice simplification for practices administering covid vaccines is the decrease in types and appearances of vials needed:
Now for the complicated details. It was clear that not all scenarios have been addressed, especially for the pediatric population. One such messy detail is the difference in age cutoffs between Moderna and Pfizer vaccines, with a transition at the 6th birthday for Moderna and the 5th birthday for Pfizer. As Dr. Sarah Long brought up in the ACIP meeting, there's not much difference immunologically in the 4 - 6 year old age group, but currently we are stuck with confusing guidance simply because the 2 companies chose different age breakdowns for their clinical trials. The FDA needs to get past this.
Also, it was very clear that ACIP (and FDA) have said nothing about spring bivalent boosters for severely immunocompromised young children such as transplant recipients. As it stands now, they have no option to receive another vaccine until perhaps fall 2023, yet they are among the most vulnerable populations. We don't have results from studies in this population, but that's not a compelling reason to hold off making a recommendation for the interim period. Perhaps other organizations (American Academy of Pediatrics, et al) need to press FDA and ACIP on this matter.
Another gap in the new guidance is what to do about healthcare providers. It seems like eons ago, but HCP were given priority in the initial vaccine rollout as a means to provide some protection to vulnerable populations and also try to preserve HCP availability to provide care during peak pandemic disease periods. It is perhaps not as crucial now, but given that some are calling for removal of universal masking in healthcare settings, how about considering a system of choosing either masking or another booster for those HCP? Masking in general isn't a big deal for most, but it is another expense and we do need to be cognizant that it does interfere with communication, especially for those whom English isn't their primary language or for those with hearing impairment and other disabilities.
CDC has updated their web page with these changes, though it's a load of words and tables that make it very tough to get the picture quickly. I"m hoping they come up with a more graphical decision aid soon. Also, a COCA call webinar to explain all this to HCP is planned for May 11, though the listing is not yet posted on their website.
Statewide Variation in Covid Policies
An article from The Lancet caught my eye. It is based on database analysis and funded by organizations mostly supporting vaccination and other public health preventive measures so must be taken with a grain of salt. However, it did demonstrate that "State governments' uses of protective mandates were associated with lower infection rates, as were mask use, lower mobility, and higher vaccination rate, while vaccination rates were associated with lower death rates." Gross domestic productivity and reading test scores were not associated with state policies, but lower 4th grade math test scores were associated in some settings.
A New Approach to Antibody Treatment
We have been through the whiplash of having effective monoclonal antibody treatments available at different times during the pandemic, only to see them rendered useless when a new variant takes over. Much research is ongoing to find a better way, and one might be the use of recombinant polyclonal antibody treatment as mentioned in this article from a California company. It's just an in vitro article, a long way from efficacy trials, but expect to see more about this approach.
Those Pesky Variants
Speaking of variants, the XBB sublineage has taken over in the US according to CDC data, and that XBB.1.16 strain that I mentioned had grown dramatically in India is now projected to have some advantage in both the US and the UK. It appears to be very agile with immune escape, but not much data yet on severity of disease. XBB.1.16 is the dark blue at the bottom of the vertical bars below.
The Simple Life
Once again I fell into the trap of being led from contemporary entertainment to the book on which it was based. This time it's the Richard Russo novel, Straight Man, on which the AMC series "Lucky Hank" is (somewhat loosely) based. I've only seen 2 or 3 of the TV episodes, but the book highlights Occam's Razor. I've used this reasoning aid in my clinical diagnosis thought process for years, even before I knew about its existence. It's been badly misquoted and misused, including in the Russo novel, but it does focus on simplicity. I loved that Russo's protagonist's dog is named Occam. I haven't yet finished the book but I am enjoying it - a humorous, sarcastic take on life in academia, some of which I've unhappily experienced.