DOCTOR IS IN by Dr. Adil Manzoor OP/ED
The way I phrased the topic is interesting, as it is premised on the assumption that vaccines reduce transmission. Before we get to the how, let’s first consider if it actually reduces transmission.
We can’t argue if the vaccines prevent serious illnesses – they do – but whether they prevent people from transmitting the virus is worth arguing.
Logically speaking, they (the vaccines) should. I mean the vaccines have the power to prevent infections – don’t come at me just yet, I’m talking of before all of these strains emerged. One would expect it to be able to prevent transmission at all. You should know that before a vaccine can be transmitted, the virus needs to have infected enough cells in the body.
After reaching this viral threshold, the person becomes infectious, and may develop symptoms of the disease within 48 hours. If the vaccine is strong enough to prevent the virus reaching this level, it should be strong enough to prevent transmission – that’s what logic says.
However, it’s never that easy with science, especially with parasites and infections. There haven’t been too many scientific studies as regards this but the few we have are encouraging. A study by the National Institute for Public Health and the Environment shows that vaccination reduces transmission to unvaccinated household members by 63% for the delta variant of the virus.
Even the WHO has claimed vaccines reduce transmission by 40%. There haven’t been too many studies on this particular topic, though, as most of the studies conducted are about the more important details – whether it reduces infection and serious illnesses.
However, it is fair to say both logic and science provide a strong indication that vaccines reduce transmission of the virus.
How does it do this? For starters, vaccines can prevent infection in the first place. There’s something microbiologists call sterilizing immunity where a vaccine prevents infection in the body, consequently eliminating any hope of transmission. This is the gold standard of vaccines, and the poster boy is the measles vaccine.
Now, the COVID vaccine doesn’t provide absolute sterilizing immunity against the coronavirus, as people can still get infected after vaccination and not just breakthrough cases. But with the introduction of booster doses, expectations are high that immunity will be strong enough to prevent the virus from causing infections and diseases.
Even if a person does get infected, the vaccines clear out the virus faster than in unvaccinated people. Let’s call on our old friend, logic. If the virus clears out of the system faster, the risk of transmission is automatically lower.
Also, studies have shown that vaccinated people have less infectious viral particles than unvaccinated people despite having similar viral load.
Vaccines are so important in this fight against the virus, and not only because it reduces the number of people that get infected with the virus. Vaccines can also help reduce transmission of the virus, meaning even when vaccinated people get infected, which is quite common now with new strains, the virus doesn’t spread as fast as without the vaccine.
The troublesome strains, like Delta and Omicron, are more transmissible than the parent virus. We have definitely seen the effects, with more and more vaccinated people getting the virus. It becomes critical for us to combat this rise in transmissibility of the virus, and vaccines plus boosters are the only weapons we have against it now.
I think this is a good place to summarize – vaccines not only reduce the risk of developing an infection at all or developing serious illnesses, but also reduce the transmission of the virus.
Please, get vaccinated. Stay safe.
This article was written by Dr. Adil Manzoor DO, a Board Certified Internist & Board Eligible Pediatrician, who works as a Hospitalist, and Emergency Room Physician. He is also the current President of Garden State Street Medicine, a non-profit organization whose sole purpose is to provide free preventive and acute urgent care services for the homeless. He is also the co-founder of his own unique medical practice Mobile Medicine NJ.
References
· https://www.bloomberg.com/news/articles/2021-02-18/can-a-vaccinated-person-still-spread-the-coronavirus-quicktake?utm_medium= cpc_search&utm_campaign=NB_ACQ_DSAXX_DSATESTTCPAXX_EVG_XXXX_XXX_COALL_EN_EN_X_BLOM_GO_SE_XXX_XXXXXXXXXX&gclid=Cj0KCQiA2NaNBhDvARIsAEw55hjPX-rh7w2H0A0ZyCtkPoEDc UfhvWWVIq3qVyp7NMfaXiTotnYY6qMaArXHEALw_wcB&gclsrc=aw.ds
· https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00690-3/fulltext
· https://www.google.com/amp/s/www.aljazeera.com/amp/features/2021/10/13/do-coronavirus-vaccines-prevent-transmission-of-the-virus
· https://www.rivm.nl/en/news/vaccination-reduces-transmission-to-unvaccinated-household-members-by-63-for-delta-variant
· https://www.nejm.org/doi/full/10.1056/nejmc2106757?cookieSet=1
· https://amp.france24.com/en/live-news/20211124-vaccines-reduce-covid-transmission-by-40-who
