COVID vaccine incapable of shedding

Dear Dr. Roach: My granddaughter refuses to let us see or pick up her 4 1/2-month-old baby because we may be shedding the virus by having been vaccinated against COVID-19. Could you please shed some light on this? We do not understand what this means. In the meantime, we are missing out on the progress of the baby, and we miss him terribly.

L.M.

Answer: “Shedding” after vaccination refers to people being contagious despite having no symptoms. Shedding is a possibility only after vaccination with a live vaccine.

Even then, it is very, very rare for a person to develop complications after exposure to a recently vaccinated person.

For example, the MMR (measles, mumps and rubella) vaccine is a live vaccine, but there has never been a published case of a person getting ill after exposure to the current version of the vaccine.

However, live polio vaccine (not used in North America for decades) had the potential to shed, and also the potential to cause illness. It has been replaced by a killed vaccine.

Smallpox vaccine can be very dangerous to a person with severe eczema, and a case was published not long ago about a young family member of a soldier who became quite ill following exposure to the soldier within a few days of smallpox vaccination.

The live chickenpox vaccine (but not the new Shingrix vaccine for shingles) has the possibility of live virus shedding, but it’s very low risk to contacts.

Rotavirus vaccine can lead to spread to household contacts if their immune system is very weakened, and there have been a few reports of diarrhea. Rotavirus vaccine and chickenpox vaccine are still recommended to be given to contacts of severely immunized people, but care needs to be taken.

Vaccines made from killed virus, vaccines made from purified proteins of bacteria or virus, vaccines which use a viral vector (such as the Astra-Zeneca and Janssen/Johnson & Johnson vaccines) and those using mRNA (such as the Pfizer and Moderna COVID-19 vaccines) cannot shed live virus. There is no risk to your granddaughter or her child.