Why is it still important to wear your mask and get vaccinated ?

I will be doing a podcast soon and this is one of the questions the interviewer asked me. I am not surprised since I am an epidemiologist by training. However, I will be honest I haven’t looked at the current research out about vaccines and masking effectiveness since the delta variant became dominant. I know they are effective based on my previous knowledge but it is time to refresh. I have been immersed with work and have not had time to learn anything new outside of that. However, I set out to review some studies and get up to speed with the current literature.

I started with looking at the current numbers for COVID19 in the United States. 56.4% are fully vaccinated as of October 2021. West Virginia has the lowest percentage at 40% while Vermont has the highest percentage at 70% fully vaccinated as of October 2021. This wide range indicates that depending on where you live you can have increased risk of getting COVID-19.

This is not ideal because in order to substantially stop transmission we would need about 95% of the population vaccinated. This is the herd immunity threshold. However, we can and should use all the tools we have available to decrease disease transmission even though we are not at herd immunity.

In general, vaccinated and unvaccinated individuals are a part of the transmission chain especially with the delta variant. This makes COVID-19 a threat still for everyone. With that said, masking and vaccination is still important. Let’s start with masking.

Why should you still wear a mask?

CDC diagram on how to wear a mask.

There is a study that shows that there is an 83% reduction in COVID-19 exposure when one person is wearing a double mask as b above or a knotted and tucked medical procedure mask as in c in the picture and the other is unmasked. There is over a 90% reduction in exposure with both parties as masked as in b and c.

As you can see above, masks can help reduce the COVID-19 rate of transmission in your community. Also, you should wear masks if you’re immunocompromised or you have kids or immunocompromised adults living at home with you or you're visiting them. Also, it would be a good idea if you live in an area with a vaccination rate less than 50% or a high transmission area to wear a mask.

Vaccination rates and transmission rates are important to determine if you need to mask or not. You’re in a moderate to high transmission area (more than 10 cases per 100,000) according to the CDC then you should wear a mask. Also, you should wear a mask if you are in an area with a greater than 5 percent positivity rate per CDC.

It is important to see how COVID19 is spreading in your county. You can find the CDC county tracker here. As you can see from the screenshot, there are not that many places with moderate and low transmission. Overall, most areas in the United States should be wearing their mask indoors.

Why should you get vaccinated?

Vaccines increases your chance of surviving if you get COVID-19. For example with the delta variant, unvaccinated and vaccinated have the same viral load. However, those who are vaccinated will have their viral load decrease by a lot once their immune system starts responding to COVID-19. For the unvaccinated, they sustain a high viral load while their body tries to respond to COVID-19. They have less antibodies to fight off COVID-19 even if they had COVID-19 previously. High viral loads are associated with symptomatic disease. Also, depending on the person(elderly or immunocompromised) a high viral load could lead to severe disease or death. https://www.nejm.org/doi/10.1056/NEJMc2104036

Decline in death rate after vaccine introduced.

You should get vaccinated to protect the health of yourself and your loved ones.

I hope you enjoyed this post. If you have any comments, let me know!

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