COVID-19 vaccine booster – Page 6 – Pediatric Infection Connection

The Post-Holiday Surge

Bud WiedermannDecember 12, 2021Leave a comment

We are now seeing the predicted post-holiday surge of COVID-19 disease in many parts of the country, driven not by the new omicron variant but by our old friend delta and fueled by high rates of unvaccinated individuals. Of course even the vaccinated and boosted are not immune from infection and, rarely, hospitalization. Expect this surge to persist for several weeks now with more holiday and indoor gatherings serving as incubators.

What Do We Really Know About Omicron?

Still relatively little, though evidence is accumulating that it is highly transmissible and possibly not highly virulent. We still don't have a lot of data on the other important trait of how well it can evade host immunity from prior natural infections or vaccination. Preliminary data strongly suggest it will to some extent, but we need more than in vitro preprint data to support that view.

I wanted to alert readers to a site I haven't mentioned before that I think gives a good graphical view of how many more mutations omicron carries, compared to our current scourge delta. A quick glance shows you the rather remarkable increase in numbers of mutations, especially in the spike protein region designated by the green band.

In the next few weeks we'll see increasingly more information about omicron that likely will allow us to chart a more informed plan of action for the coming months.

Should 16 and 17 Year-Olds Get a Booster?

As most of you are aware, the FDA authorized the Pfizer vaccine for booster doses in this age group, and the CDC stated that these individuals "can" (rather than should) get boosted. It boils down to a risk/benefit consideration, particularly since this may be the prime age group for development of the rare (and generally mild) complication of post-vaccine myocarditis. It doesn't appear that the FDA had any new data, other than Pfizer's request, to make this authorization. So, it may be useful to look back at the myocarditis risks presented previously by CDC colleagues. At the November 19 ACIP meeting, CDC presented data on myocarditis rates based on VAERs data through August 18. At that time, the highest post-vaccine myocarditis risk was in males in the 18-29 year-old age group, with a rate of 13 cases per million vaccine doses. Obviously this is extremely low, and in fact a booster (assuming that vaccine efficacy declines from the primary series) would prevent 114 million hospitalizations per million doses in this same age group, counting both sexes. So, those data still pretty clearly favor boosting but does not give us anything more specific for 16-17 year-olds. However, I doubt the numbers would be terribly different.

Trying to transform these rare risk event numbers into something understandable for most people is tough, plus we have no idea how the omicron variant and potential need for vaccines modified for omicron will figure in. I think probably the best plan for healthcare providers is to mention the "can" versus "should" CDC statement as an indication that the data aren't as solid as for older individuals, but I wouldn't necessarily wait on an omicron vaccine to appear - it isn't even clear that we will need it, plus it will take a least a few months to become available. In the meantime, we can expect the holiday delta surge to continue.

Giving Thanks

Bud WiedermannNovember 21, 2021Leave a comment

As we enter our second pandemic Thanksgiving holiday, I'm reminded we have a lot to be thankful for compared to a year ago. This time last year the only people who were vaccinated against COVID-19 were the relatively small numbers of subjects randomized to receive vaccine in the clinical trials. Now we know that our approved and authorized vaccines are both safe and effective and clearly have put a dent in the pandemic in the US. Also, we now have treatment options including two oral medications making their way through the FDA evaluation process. Unlike last year, many families will be able to gather safely to celebrate the holiday. For those that do, please be safe both in your travel plans and in your infection control practices.

The Number Needed to Vaccinate

Last week the FDA authorized booster doses of mRNA vaccines, and subsequently the CDC/ACIP met on November 19 to make their recommendations. Now everyone 18 years of age and older can get a booster if desired.

I won't bother to recite all of the data presented, suffice to say the new experimental data submitted by Pfizer and Moderna consisted primarily of antibody titers one month after a booster dose, along with some limited safety information. I did want to mention the number needed to vaccinate (NNV) just to give you an idea of how many people benefit from boosters at different age groups. NNV is a spinoff of the term number needed to treat which is another way of looking at data beyond p values. It was hoped it would be useful in explaining risks and benefits to lay people, but that hasn't quite been realized.

Dr. Oliver's presentation at ACIP looked at NNV for different age groups, telling us how many people would need to be vaccinated to prevent one additional person being infected or hospitalized with COVID-19. Slides 37 and 38 in her presentation display the data in graphical form.

Speaking just about the Pfizer data (NNVs are higher - i.e. less beneficial - for Moderna due to longer persistence of antibody), for persons like me 65 years and older 481 would need to receive a booster dose to prevent 1 additional hospitalization over a 6 month period. That's not bad, but of course the numbers get higher in the younger age groups. For 50-64 NNV is 2051, then 3361 for 30-49 year-olds and finally 8738 for the 18-29 year age group, which is not a great benefit. Know that these are predictions based on modeling and a lot of assumptions, but I think they are useful numbers to help you understand the magnitude of booster benefit. If you are like me, you're getting a lot of questions from parents about booster doses for teenagers and younger. Don't worry too much about that now, boosters aren't likely to be a big help for them. We'll know more once the children in the clinical trials have 6-month antibody levels drawn, coming soon.

Addressing Vaccine Hesitancy

Boosters aren't the way out of this mess, we still need to vaccinate the unvaccinated. According to multiple polls, a core group of adults in the US aren't going to be convinced to choose vaccination no matter what data are explained. They have made a decision and only choose to look at information that supports that decision. However, a lot of unvaccinated folks are open to discussion. For them, a new toolkit from our surgeon general, Dr. Vivek Murthy, is a good approach to try to correct misinformation. His advice to healthcare providers has 5 points: Listen, Empathize, Point to credible sources, Don't publicly shame, and Use inclusive language. It's a 22-page easy read, please take the time to look it over and decide how you can use it in your practice.

Dazed and Confused?

Bud WiedermannSeptember 26, 2021Leave a comment

Well, maybe not dazed, but then I couldn't have a movie reference. Every outbreak manual I know of stresses the importance of clear messaging from authorities. That's been lacking with the booster roll out.

How Can You Follow the Science When It Doesn't Provide Answers?

That's probably the underlying problem brought to light at the recent FDA/VRBAC and ACIP/CDC meetings discussing COVID-19 vaccine booster plans. I commented a bit last week on the first meeting, but the ACIP/CDC meeting and its aftermath really shook things. up. I was able to attend most of the proceedings, especially the meatier parts and the discussions. At the risk of over-simplifying an extremely complex issue, the current data just don't answer the question of whether boosters now will have any great benefit for individuals receiving them or any impact in calming or preventing surges. The only likely benefit is for the "elderly," (yes, it still irks me that I fall into that category) and even that isn't entirely conclusive. Thus we are down to risk/benefit discussions that suggest moving towards the riskier side of the scale at younger ages. My 35-year-old son, also a healthcare provider, received his Pfizer primary series last January. He asked me if I thought he should get a booster and I was able to respond generally yes, with some caveats about potential rare myocarditis risks. As pediatric healthcare providers, the patients asking our advice are likely to be in the 18-25 age range where potential benefits to the individual seem to be very low, so even small risks start to become a consideration. Look at Dr. Thornburg's great explanation of immunity and SARS-CoV-2 as well as Dr. Oliver's presentation, slides 46 and 47 in particular, for a good discussion on risks and benefits for different ages and circumstances.

As for me, about 8 months out from completing my primary Pfizer series, I suppose I will get the booster when it is offered to me, but no big deal if I have to wait a bit. I will be getting my flu vaccine soon.

More School Studies

MMWR published 3 Early Release articles on September 24. They don't necessarily tell us anything new but are important because the all suggest that masks, along with other mitigation strategies, still are highly effective in the delta variant era.

Two of the studies were headed by CDC with help from other institutions. One looked at pediatric COVID-19 cases from July 1 - September 4, 2021, in counties with and without school mask requirements. After the start of the school year, the increase in daily case numbers was much higher in the counties without school mask requirements compared to those with mask requirements. The other study looked at mask use effects on school closures and learning modality changes from August 1 - September 1 and again found evidence in support of mask requirements.

The third study was limited to Maricopa and Pima counties in Arizona and carried out in July and August. These counties comprise 75% of the state's population, and the study concluded that the odds of a school-associated COVID-19 outbreak was 3.5 times higher in schools without a mask requirement compared to those with mask requirements implemented early in the school year which began in July.

All of these studies have significant limitations; it is very difficult to control for all of the potential confounding variables. However, masking requirements in schools, coupled with multi-layered infection control measures, still work extremely well in the delta era. We all need to concentrate on that, as well as trying to vaccinate the unvaccinated.

Tag: COVID-19 vaccine booster