Better Data on Risks of Myocarditis and Pericarditis from COVID-19 Vaccines
The ACIP/CDC held their meeting, postponed from June 18 due to the new federal Juneteenth holiday, on June 24. It was worth the wait, and fortunately I was able to attend the meeting online. You can see all of the presentation slides on their website, in particular I'd recommend the risk-benefit discussion by Drs. Wallace and Oliver. I had 2 major take-aways from the approximately 5-hour presentation.
First, as more time and cases have accumulated, the link between vaccines and myocarditis/pericarditis in adolescents and young adults (primarily male) seems much more convincing. The timing after the second dose, the striking age distribution, and the mostly mild clinical features strongly suggest a link even though the rates are very rare. It is worth mentioning this potential risk to people considering vaccination, though in these same demographic groups the risk of adverse sequelae from COVID-19 disease itself is much higher. Also note that this association was seen with both of the mRNA vaccines, Pfizer and Moderna, but I don't think we have enough information yet to know if this will occur with other COVID-19 vaccines. The mechanism of injury is still unknown and is the subject of much research.
Second, recognize that the only reason this was brought to light so quickly is that we have very massive and effective surveillance of adverse events with these vaccines. Please encourage all of your patients to sign up for V-safe when they are vaccinated, and everyone should report any suspected vaccine adverse events to the VAERS system.
Delta Variant is a Real Problem Everywhere
Evidence continues to mount that the SARS-CoV-2 delta variant is a major problem worldwide. It is unquestionably more easily transmissible than other variants by a long shot. Both mRNA vaccines seem to provide very good protection against severe disease caused by the delta variant, though preliminary data suggests that a single dose, rather than the recommended 2 doses, is not very protective. The jury is still out about whether delta causes more severe disease than other variants, but clearly this is the strain responsible for the vast majority of hospitalizations in developed countries, primarily impacting children and young adults who represent a disproportionate number of unvaccinated individuals. It likely will be the dominant strain in the US in a matter of weeks. Please encourage everyone to be vaccinated.
Somewhat more in the rumor category, a "delta-plus" variant has cropped up in the lay press. It is a strain that carries an additional mutation, K417N, that was known to be present in the beta variant and has been associated with poor response to treatment with monoclonal antibody preparations. We still need more information about this new sub-lineage strain to know its clinical significance.
Brief contrarian question - because I am
Already being asked by parents : how do we know these mild cases of myocarditis will not cause long term problems , such as , ventricular arrhythmia and sudden death ?
If that is seen , would we still recommend this vaccine ?
If so , how would this be different than the logic that resulted in the withdrawal of Rotavirus vaccine over intusseception risk ?
Not contrarian at all, plus I think very helpful to all frontline providers to know what types of questions are being asked.
Bottom line for everything in medicine, we have a degree of uncertainty in all our decisions/advice. I think the medical field in general has been particularly poor in conveying this uncertainty to the public at large. There are very few certain things in medicine.
So, this really comes down to weighing the benefits and risks. If you look at the presentation by Wallace at the CDC web site that I mentioned, you'll find some good numbers that address this. Based on the best available data, the risks of bad outcomes (e.g. hospitalizations, ICU admissions, and deaths) from COVID-19 in adolescents and young adults far outweighs the risks of myocarditis from the vaccine. This is particularly true since the cases that could be associated with the vaccine are very mild, with resolution of symptoms and lab/ECG abnormalities usually within days. We still need long-term follow up of those folks, but it's hard to imagine any serious long-term risks.
One thing that might be helpful to families is a comparison to other types of risk we don't often worry about. For example, a ballpark figure for risk of being struck by lightning is 2 per million persons per year. That is similar, but somewhat less than, the highest risk observed for myocarditis associated with second dose of COVID-19 vaccination which is around 12 per million second doses. Being struck by lightning of course has much greater consequences, both immediately and long term if one survives, than does the apparently mild cardiac inflammation with vaccination.
The odds of being in a car crash vary widely depending on behavior but of course are highest in the same age group we are talking about for the vaccine risks. Lifetime risk for dying in a car crash is about 3 in 1000 persons; the average person is involved in 3 or 4 car crashes in a lifetime. No matter how you want to massage these numbers, riding in or driving a car is far riskier than the COVID vaccines. Maybe ask parents if they have ever been in a car crash, or if they know someone who has died in a car crash. That could be something they can relate to.