An ongoing dialogue on HIV/AIDS, infectious diseases,
January 18th, 2021
COVID-19 Vaccine Frequently Asked Questions
In case you missed it, over on the New England Journal of Medicine, we now have a list of Covid-19 Frequently Asked Questions.
(Why this NEJM Journal Watch site and the actual New England Journal of Medicine use different capitalization rules for this disease is a mystery. And don’t get me started on the Washington Post, which writes it as “covid-19”– all lower-case.)
It’s been a fun project to put these FAQs together, and my great hope is that it’s useful to clinicians and others who have questions about these amazing vaccines. Turns out I’ll learn a lot too.
So far, the single question that has drawn the most attention is this one:
Do the vaccines prevent transmission of the virus to others?
In my response, I try to highlight the fact that while we don’t have ironclad proof, it is highly likely that they will lower the risk. I urge you to read the full question where I outline the evidence so far.
In my response, however, I wrote this:
If there is an example of a vaccine in widespread clinical use that has this selective effect — prevents disease but not infection — I can’t think of one!
Some colleagues now have pointed out a few examples — diphtheria, meningitis B, and pertussis. My apologies for not mentioning these! We will update the site, and thanks for pointing this out.
Nonetheless, the general (if not ironclad) rule that vaccines typically reduce the risk of transmission to others remains true. After all, this is the primary reason why we have policies on mandatory school immunizations, influenza vaccines for hospital employees, and country-specific entry requirements for the yellow fever vaccine. Rubella immunization in particular is critical to prevent transmission of this otherwise benign infection to pregnant women. We also stress the importance of having immunizations up to date for people living with a person with a weakened immune system for this reason.
Sometimes it turns out to be an ancillary benefit of vaccine recommendations. This happened with expanded childhood immunization for pneumococcal disease, which has lowered the incidence in adults.Thanks, kids!
And it can be a great additional motivating factor for people considering the vaccine who might otherwise be undecided. Getting the shot protects you and protects others.
The challenge for us — as summarized in the New York Times — is communicating optimism about the vaccine’s high likelihood of reducing transmission, while at the same time acknowledging that we don’t yet know how much they’ll do so.
The overall message of the piece is that we’re “underselling” these vaccines. That the proven benefit of preventing severe disease is being undermined by caveats regarding disease transmission — about which we have limited, but promising, evidence.
(I suspect it will be a lot, though not 100% — but we’ll see.)
What to do practically in the meantime is also tricky, especially since the vaccine roll-out will be a process that takes months.
Here I totally agree with this piece’s well-stated conclusion, which I’ll quote in full.
We should immediately be more aggressive about mask-wearing and social distancing because of the new virus variants. We should vaccinate people as rapidly as possible — which will require approving other Covid vaccines when the data justifies it.
People who have received both of their vaccine shots, and have waited until they take effect, will be able to do things that unvaccinated people cannot — like having meals together and hugging their grandchildren. But until the pandemic is defeated, all Americans should wear masks in public, help unvaccinated people stay safe and contribute to a shared national project of saving every possible life.
Perfect! And looking forward to a time when the proportion of unvaccinated people is much smaller than it is today.