Katie writes:

Hi Dr. Griffin,

Thank you for all that you do! I am newer to TWIV, so I apologize if you have already addressed questions similar to mine.

My son just turned 5 in February, and received his first of two Pfizer vaccines. The pediatrician recommended that he returns in three weeks for his second dose. However, I have heard you talk about the more effective timing between doses is a little longer. When I asked the pediatrician about it, I felt like I received a canned response about what the CDC currently recommends. I of course want to do whatever is going to be the safer and more effective option.

Just a little background, my son suffers from recurrent croup that has landed him in the ER twice in the last few months. He tested negative for COVID both times, but positive once for RSV and positive for the common cold the second time. Of course my fear is how his body would react to actually getting COVID. The other complication is that his 2-year old sister has a rare form of cancer, so we have to protect her as well by the rest of the household getting vaccinated.

Given our situation, what would you recommend as the best timing between doses? Due to a scheduling conflict, his second vaccine is actually scheduled 4 weeks out from his first, instead of 3 weeks.

Also, can you clarify what MIS-C is? Is this something that children are getting as a side effect from the vaccine, or is this what you are seeing in children who actually get the virus?

I very much appreciate your work and your time!


John writes:

Hi Daniel,

As always, thanks for your wonderful clinical updates. 

What would be the optimal timing for an mRNA booster in pregnancy given the following situation:  My friend is a 32 year primiparous woman with an uncomplicated pregnancy at 21 weeks. She had two doses of an mRNA vaccine prior to her pregnancy and got a mild case of covid just before she was to get her booster, at 8 weeks. She recovered from the mild covid without incident and had only mild reactions to the two vaccines doses. Given that she has had three exposures to spike through two vaccines and one infection, what is the best timing for her booster? Our covid prevalence in rural Wyoming is finally very low and her habits make her exposure risk low. One could argue that putting off the dose until, let’s say 36 weeks, might afford her with better protection for the fetus and newborn rather than a earlier dose, say next week, in which antibody levels might be waning by the peri partum window. Also, although the robust MMWR report shows no evidence of preterm delivery, a hypothetical advantage of waiting until 36 weeks might be also less implications should a high fever or reactogenicity trigger preterm labor. 

Your thoughts?

Again, many thanks to you and Vincent for your great updates and for your sound and balanced regard for the science. 


Jen writes:

Hi Dr Griffin, 

Thank you so much for your hard work and diligence. My 83-year-old mother with multiple comorbidities received her first booster mid-November, was positive for omicron on Jan 23rd, received Sotrovimab on Jan. 25th. I’ve read two distinct opinions: some say no need to wait for vaccination/booster after Sotrovimab infusion, other places are saying wait 90 days. 

My mom is raring to go to get her second booster but only 60 days have passed since her infusion. Should she wait till April 25th when 90 days have passed since her monoclonal antibody infusion or can she get her booster sooner?

PS–because I listened to your weekly updates, I knew exactly what to do when she tested positive. I’m so grateful. She is doing great now and has no lingering symptoms or issues.



Megan writes:

Dr. Griffin,

I am 32 years old, thin and healthy. I had 100 mcg of moderna in August 2021 and due to my reaction, I waited to get another vaccine, dose 2 of moderna, in December, 4 months later and only received 25 mcg. My antibody level in January ’22 was >2500.

I have had chronic lymphocytopenia for many years, my earliest labs available are 2016 or 2017. My absolute lymphocyte count fluctuates between 1.0 and 1.4 and both my lymphocyte percentage and neutrophils are in the normal range. Through listening to TWIV and reading articles about b cell and t cell immunity I started to piece together that my counts are not that different from some of my cancer patients (I work part-time as a nurse in a small cancer clinic), usually their lymphocyte count is better! I recently saw an immunologist and I was not deemed immunocompromised because I made antibodies to the vaccine and clinically/symptomatically I am healthy, not getting extra infections. We don’t know why I have this, my mother has anklosing spodylitis, no immunosuppressive medication and has the same counts as me. A google search will bring up countless studies on lymphocytopenia and a severe or bad prognosis with covid. I have looked through cases and studies and it is with counts that are not that low, even 1.0 where patients aren’t doing well or dying. Everybody seems to drop, but I’m already normally in that “risk zone”, how far will my lymphocyte count drop? 3 years ago I was hospitalized with norovirus and my ALC was 0.6, the only time it has gone below 1. Am I at risk for a bad prognosis? I need someone who understands immunology and has been at the covid bedside. Dr. Griffin, would you be able to explain what lymphocytopenia looks like in covid and how that affects outcome? As it stands I do not qualify for any treatment like Paxlovid and I am terrified to rely on my immune system. Does vaccination help in my case? I can’t get boosted until May or June. 

Thank you so much for what you do! I have previously been on the covid unit and am trying to overcome some trauma related to that. I wish I could feel safe.