Here’s a short summary of COVID news and information that I found interesting, along with links for further reading.
Local COVID Case Data
The local rate of infections in St Mary’s County is finally dropping again. We’ve got a LONG way to go to get it under control: there are still about 300 new cases per week being reported, and about 15-20 hospitalizations per week – as high as the peak last winter – but it’s finally decelerating for the last couple weeks.
I am hopeful that by around Thanksgiving we might be back to a reasonably low level. Of course, Thanksgiving and Christmas were triggers for a massive surge last winter – so it will be very important to be careful this winter too, during family gatherings.
Mix-n-Match Vaccine News
The FDA approved “mix-n-match” COVID vaccine boosters on 10/20/2021,
https://apnews.com/article/coronavirus-pandemic-science-business-health-coronavirus-vaccine-5ba0ada40600e590fc3ab38bba046a94
and the St Mary’s County Health Department quickly began offering them (the very next day).
https://mailchi.mp/maryland/news-release-expanded-eligibility-for-covid-19-vaccine-boosters-in-st-marys-county-4948996
This means that you can get a different vaccine as a booster than the first vaccinations you got.
This is good news, because studies have shown that getting Moderna after Pfizer, or Moderna after J&J, provides much stronger immunity than sticking with the original. (Moderna has proven to be the best at disease resistance and immunity.)
https://www.nytimes.com/2021/10/19/health/covid-vaccine-mix-match.html
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01694-9/fulltext
Studies show that getting the second Pfizer shot a couple months after the first shot actually produces much stronger and longer-lasting immunity than only waiting two or three weeks. It appears that the body has time to build up a better response after the first shot, so the second shot does a far better job of producing lasting immunity.
https://www.nature.com/articles/d41586-021-01299-y
Immunity News
It appears that the protection conferred by the mRNA vaccines (Pfizer and Moderna) is proving to be long-lasting. This is very encouraging, as some initial data from Israel indicated that it might wane rapidly. There is still a real chance of getting a breakthrough INFECTION, but the chance of actual harm from a breakthrough infection is generally low. (Local data shows about 25-30% breakthrough infections.)
https://www.nejm.org/doi/full/10.1056/nejmc2103916#
https://www.nytimes.com/2021/08/05/world/moderna-vaccine-efficacy.html
Studies have shown that the immunity conferred by natural cases of COVID are fairly short-lived – it’s nearly equally possible to get reinfected after just three months, as getting infected in the first place. So please don’t count on a past infection to protect you from a future infection.
https://www.science.org/doi/10.1126/science.abf4063
https://www.advisory.com/daily-briefing/2021/10/06/reinfection
In fact, one study found that 36% of confirmed COVID cases did NOT have any measurable residual antibodies at all.
https://wwwnc.cdc.gov/eid/article/27/9/21-1042_article
Another study found that “65% of people with a lower baseline antibody from infection to begin with completely lost their COVID-19 antibodies by 60 days.”
https://www.nebraskamed.com/COVID/covid-19-studies-natural-immunity-versus-vaccination
The above thoughts about vaccines versus natural immunity are controversial, with some studies showing equal or greater immunity. So do your own reading. These articles cover both sides of the discussion. My conclusion is that the studies generally show that while immunity may be initially higher for natural infections, the vaccine immunity is longer-lasting and more predictable.
https://www.bmj.com/content/374/bmj.n2101
https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1
https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html
What Protects Us Best – Vaccination or Actual Infection?
Fortunately the best case seems to be actual vaccination AND a natural infection. So if you previously had COVID, please consider vaccination anyway – you’ll dramatically increase your resistance to new infections and illness. But if you’ve avoided it so far and you’re not yet vaccinated, please don’t go TRY to get infected first; the risk of hospitalization (15%) and “long COVID” (50%) is just too high.
https://www.nbcnews.com/health/health-news/hybrid-immunity-people-covid-still-get-vaccinated-rcna1974
You may see studies showing that the rate of reinfection was around 1% in several months after the first infection. “Wow,” you might say, “that sounds low, so I have no worries about reinfection; I’ll take that risk.” However, consider that 6% of St Mary’s local population has been infected in 19 months, so the first-infection rate in 3 months is ALSO about 1%. In other words, the chances of reinfection are about the same as for the first infection.
Also, please note that with natural immunity, protection can vary greatly. You might be completely immune to one variant, but not at all to another. This is because the immune system may select a protein to attack, that differs from another variant. Natural immunity may pick from many possible proteins. But the vaccines were intentionally developed to provide protection against very specific proteins that are known to be very stable across variants and unlikely to mutate.
https://www.medicalnewstoday.com/articles/delta-variant-what-kind-of-immunity-offers-the-highest-protection#Natural-immunity-and-one-vaccination-may-offer-best-protection
On the other hand, those who get vaccinated have reliably between 50% and 90% immunity at five months, and initial data appears to show that the immunity will likely stabilize and not decay to zero.
Unfortunately, I find that our local “total immunity” in St Mary’s County is not very encouraging. Based on the expected residual efficiency of the mRNA and J&J vaccines, plus the decay of protection to natural COVID infections, my estimate is that we’re only about 50% immune right now (53% fully vaccinated, and 9% infections, then adjusted for time since vaccination or infection). That’s a LONG way from the expected 80% required for “herd immunity” to the Delta variant. And St Mary’s County is lagging far behind most other Maryland counties in vaccination – which is why our county also has one of the highest rates of COVID infection and hospitalization in the entire state.
http://www.smchd.org/covid-19-data/
The data is very clear: vaccination works.
https://twitter.com/CDCgov/status/1450567471698751490
Another takeaway from the vaccination, hospitalization, and case data is that higher community spread (as we have right now in our county) leads to higher infection breakthrough percentages and also higher hospitalization and death breakthrough percentages. In other words, when more people get vaccinated, breakthrough rates fall, and hospitalization and death rates fall even faster. It’s NOT a linear relationship. Put simply, the best way we can all help each other is vaccination.
https://www.eehealth.org/blog/2021/08/what-breakthrough-infections-mean-for-the-covid19-vaccine/
and 
or join our email notification list.