BUHealth: Wonderful news about vaccines and alternative strains

This JAMA research letter came out on March 19, 2021, but it is trending #1 on JAMA, and seems worth highlighting since it gives such hopeful news.

The study compared measures capturing rates of antibodies in three sets of patients: 20 people actively infected with COVID-19, 20 people who had recovered from COVID-19 for 32-94 days, and 14 people who had just finished their second vaccine of Moderna dose 14 days earlier (hence arguably at their maximal responsiveness to the vaccine). Note that these antibody tests are measuring antibodies, related to how well the body is prepared to fight off COVID, not for the virus itself. A higher number is better.

Importantly, the study examined not only the original Wuhan strain that was used to test and approve Moderna and other vaccines, but also three variants that reflect recent concerns, including B.1.1.7. The results are wonderfully summarized in the (Figure) shown below.

The figure makes comparisons across the three types of patients and four strains. Focus on the means and confidence intervals.

Across patient samples:

Not all actively infected are yet protected with antibodies, as expected.

Eventually, convalescent people (recovered infectees) show high rates of antibodies with only one sample showing no signs of being protected, as defined by the low gray line.

All of the Moderna vaccinated sample shows high rates of antibody protection. Scientists are tracking changes in these rates over time, but so far they are encouragingly gradual declines.

Across variants:

More encouraging, across the four COVID-19 strains, there were no statistically significant differences in rates of antibody effects among the two naturally infected groups. ( people infected with A1 appear likely to be almost equally protected against the newer variants. There is a small difference in the strength of antibodies within the vaccinated sample, but the difference is still very small relative to the natural rate of antibody protection observed in the convalescent sample. In short, the Moderna vaccine appears remarkably successful against all four strains considered, even if not exactly as effective against the more recent strains.

This is great news!

My own comment is: The similarity of the effectiveness of the various vaccines suggests similar results are likely with the other vaccines.This is not in the article.

As the article concludes,

“Limitations include the small sample size, possible selection bias, lack of clinical outcomes, and how neutralization titers correlate with protection.”


Research Letter

March 19, 2021

Neutralizing Antibodies Against SARS-CoV-2 Variants After Infection and Vaccination

Venkata Viswanadh Edara, PhD1; William H. Hudson, PhD2; Xuping Xie, PhD3; et al Rafi Ahmed, PhD2; Mehul S. Suthar, PhD1

Author Affiliations Article Information

  • 1Emory University Department of Pediatrics, Atlanta, Georgia
  • 2Emory Vaccine Center, Atlanta, Georgia
  • 3University of Texas Medical Branch, Galveston


Neutralizing Antibodies Against SARS-CoV-2 Variants After Infection and Vaccination





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