We have clinical trial data that Moderna, Pfizer, and J&J work really well. And, work better than we hoped (we were originally shooting for a >50% efficacy rate).
We have “real-world” data that Pfizer worked really well in Israel.
And now, we have “real-world” data that Moderna and Pfizer work really well in the U.S. The CDC published results from a landmark study (called HEROES-RECOVER) on March 29, 2021.
Who was in HEROES-RECOVER?
3,950 health care personnel, first responders, and other essential and frontline workers in 8 locations across the United States (Phoenix, Arizona; Tucson, Arizona; Miami, Florida; Duluth, Minnesota; Portland, Oregon; Temple, Texas; and Salt Lake City, Utah).
What did the participants do?
They were asked to complete weekly SARS-CoV-2 testing for 13 consecutive weeks. Participants self-collected nasal swabs (eek- I don’t know if I could do this) regardless if they had symptoms or not. Then, sent their samples to a central lab for PCR testing.
What did they find?
When participants were unvaccinated, the group had 161 infections. After partial vaccination (≥14 days after first dose), 8 people were infected. After full vaccination (≥14 days after second dose), 3 people were infected. This equates to:
90% effectiveness after full immunization
80% effectiveness of partial immunization
Why is this important?
Clinical trials are tightly controlled and (sometimes) do not accurately reflect what happens in the real-world. Environmental exposures, genetics, cultures, life can get in the way. This can decrease effectiveness of vaccines. This study showed that the vaccine still works when we take all of this into account.
Considerations…
This study is very exciting. But, it left me with more questions than answers.
There was some really confusing data in here. And the transmission question wasn’t answered. Infection does not equal disease. So, for example, I would have liked to see more information on those 11 people with a positive PCR test. Yes, they had a positive test, but did they have symptoms? 10.7% of the overall sample was asymptomatic but who were they and to what degree? If they had symptoms, to what degree? What was the viral load among people with symptoms vs. people that didn’t have symptoms? What was the viral load for those that didn’t test positive at all? There were two hospitalizations. Again, who were they and when? You can’t just drop this on us with no context.
Effectiveness: During this time period, cases were decreasing, so could that explain decreased effectiveness vs. efficacy? Statistically, we can adjust for this. Which wasn’t done in this study.
Selection bias: These participants are not the “general population”. They are exposed to a high degree, but also are more likely to continue to mask up and be careful (I think). It would be interesting to see these results among the general public too (which I’m sure is coming).
All studies have limitations. Some of which you can control and some that you cannot. It’s the nature of the beast. It’s also WAY easier to be critical when you’re just reading the study than actually conducting it.
Still lots of questions to answer. But one thing is clear…
Get. that. vaccine. in. your. arm.
Love, YLE
Yes, it’s easier to criticize than to conduct studies, but the study population makes it hard to generalize the results. They’re kind of the equivalent of the 18 year old white male college student subject if yore.
“About 72 percent of the participants were 18 to 49 years old and the majority were female. Most participants were White and healthy, with no chronic medical conditions.”
https://www.washingtonpost.com/health/2021/03/29/vaccine-effective-essential-workers-study/?utm_campaign=wp_main&utm_medium=social&utm_source=facebook&fbclid=IwAR2ORZSYkMTXwH2wdxjtvn5LcgTpXcXwGKW0S9D8wze4lkJj0LW15cWC6VQ
I found the headlines on this very confusing. Do we happen to know how likely it is for someone to be contagious after vaccination? I’m sorry to ask again if you have already answered this question.