An Urgent Message to My Nurse Friends, and Colleagues, at the Hospital of the University of Pennsylvania: A Safety Warning About Pfizer’s COVID-19 Vaccine.

Penn Nurses and other frontline providers are at much higher risk of being asymptomatic Carriers of the SARS-CoV-2 virus — in a setting where Pfizer and FDA excluded such subjects from the Safety trials of the novel COVID-19 Vaccine. This omission poses a safety risk to any Penn nurses and frontline providers who may be asymptomatic carriers.

Addendum: Following my initial publication of this open letter to HUP Nursing, I received an email from Dr. Bill Gruber, SVP of Pfizer’s vaccine development unit, on 12/14/2020. He informed me that the Phase 3 part of the Pfizer trial had, in fact, included about 300 asymptomatic carriers — and that these subjects did not develop serious adverse events. However, unfortunately, this number of subjects does not provide sufficient statistical power to detect a safety signal in the range of 1–5%. I believe that Dr. Gruber and the FDA leadership fully appreciate this scientific problem with the safety data. So, I proposed to Dr. Gruber that Pfizer and OWS ought to consider rapidly expanding into a Phase 1 trial in asymptomatic carriers — and in the meanwhile to provide any vaccine candidates with the option to be screened for COVID-19 prior to being vaccinated. I suggest that all frontline healthcare providers #ScreenB4Vaccine.

Dear Friends,

Yesterday, December 10, 2020, I attended the FDA hearing focused on Emergency Use Authorization (EUA) for Pfizer’s new COVID-19 vaccine.

I want to share my concern about this vaccine with you, my friends, so that you can maximally protect yourselves from COVID-19.

I’ll start by stating that the science and the data indicate that Pfizer’s COVID-19 vaccine is highly likely to be one of the most effective vaccines ever created in human history.

But, efficacy is not a guarantee of safety — as you all know.

What struck me most about the hearing and the data presented was the striking and dangerous deficiencies in the Phase 1 safety trial design for this vaccine.

Specifically, a critical group of subjects was entirely excluded from the Phase 1 portion (i.e., safety part) of this trial: That is, vaccine recipient who are asymptomatic carriers of the SARS-CoV-2 virus.

Why is this omission dangerous and very specifically relevant to you as frontline providers at HUP?

For two reasons:

  1. There are very strong scientific and immunological reasons to be concerned that vaccinating asymptomatic carriers of SARS-CoV-2 with this powerful new vaccine could directly trigger a systemic COVID-19 inflammatory disease.
  2. As front line workers treating COVID-19 patients you and your colleagues are at far higher risk of being asymptomatic carriers of the virus.
Drs. Peter Marks and Janet Woodcock are the FDA leaders who have been fully informed and briefed about the potential immunological danger of vaccinating asymptomatic SARS-CoV-2 carriers. Additionally, Dr. Marks is fully aware of the fact that asymptomatic carriers were actively excluded from Pfizer’s Phase 1 clinical trial of the novel Coronavirus vaccine. This omission is a critical safety concern for all frontline healthcare providers.

Unfortunately, despite my attempts to inform the leadership of the FDA panel, including FDA’s Dr. Peter Marks, I was unable to elicit discussion of this serious concern at yesterday’s panel discussion.

So, I believe that it is up to you, as nurses and frontline providers, to demand that you be 100% and reasonably protected from harm.

Let me be clear, there is almost no doubt that this new COVID-19 vaccine will be highly effective at protecting you.

BUT, there is a high likelihood that if you are an asymptomatic carrier of SARS-CoV-2, the vaccine could trigger a systemic COVID-19 inflammatory disease in your body.

So, in the absence of FDA and Pfizer leaderships willingly and publicly addressing this critical deficit in Pfizer’s Phase 1 safety trial data, it is up to you to protect yourselves and to demand that the HUP administration does so too.

As your friend, as a friend to an institution I grew up in and love, and as an immunologist and a physician, I am recommending that every one of you demand to be PCR screened for SAR-CoV-2, BEFORE undergoing vaccination with the Pfizer COVID-19 vaccine at HUP. If you are an asymptomatic carrier, delay your vaccination until such time when you are negative.

Executive VP and Dean of Penn Medicine, Professor Larry Jameson. Penn Medicine and HUP can easily afford to screen all COVID-19 vaccine candidates in its ranks for the SARS-CoV-2 virus — in order to protect asymptomatic carriers from a potential vaccine induced systemic COVID-19 disease.

It is not too much to ask the HUP administration to protect you all by ensuring that no front line provider at HUP is an asymptomatic carrier of SARS-CoV-2 at the time of vaccination. The cost of protecting you in this way to Penn Medicine is minimal.

I hope that you will understand that our nation’s understandable rush to achieve an effective COVID-19 vaccine seems to have compromised the integrity of the Phase 1 safety part of the Pfizer’s evaluation — specifically, by excluding asymptomatic carriers from the subject pool.

Every frontline nurse and practitioner at HUP, and nationwide, is at much higher risk than the general population of being an asymptomatic carrier of SARS-CoV-2 — in a setting where we do not know if vaccinating such people with the Pfizer vaccine is safe.

I humbly suggest that it is your duty to your families, your institution and our nation to demand that FDA’s safety lapse be mitigated at the leadership of Penn Medicine — it is a very simple matter for institutional leaders at HUP to screen all vaccine candidates to protect asymptomatic carriers from any potential risk.

In considering HUP’s upcoming offer/mandate for you to be vaccinated with the Pfizer vaccine, the critical question you ought to ask yourselves is whether you are willing to accept a potential immunological morbidity/mortality risk to yourselves, or those of your colleagues who may be asymptomatic carriers of SARS-CoV-2.

I write this urgent letter of warning to you, my friends, and ask that you please share it with any and all frontline healthcare providers at HUP and across the nation, whom you know might be candidates for the new Pfizer vaccine.


In friendship and with respect,

Hooman Noorchashm MD, PhD.


Hooman Noorchashm MD, PhD is a physician-scientist. He is an advocate for ethics, patient safety and women’s health. He and his 6 children live in Pennsylvania.