Can the third shot of the new crown vaccine "enhance" immunity?

With the epidemic of the new crown variant virus and the repeated epidemics in some areas, is it necessary to inoculate a third dose of the booster new crown vaccine, especially for people with weakened immune functions or people who have a poor response to the vaccine, do they need to be given a "boosted shot" to become people Issues of concern

Today, the New England Journal of Medicine (NEJM) published the results of an important clinical trial

The research institution pointed out in the press release that this is also the world's first randomized placebo-controlled trial of the third dose of the new crown vaccine among organ transplant recipients

An editorial article published by NEJM in the same period pointed out that people are concerned about the weaker immune response of transplanters after the standard two doses of mRNA vaccine.

Screenshot source: The New England Journal of Medicine

The trial included 120 organ transplant recipients, with a median age of 66.

Before the third dose, the two groups of patients had similar levels of antibodies and neutralizing antibodies against the receptor binding domain (RBD) of the new coronavirus spike (S) protein, and their immunosuppression conditions were also very similar

The primary endpoint of the trial is that the level of antibodies against RBD is greater than 100 U/ml

▲The level of anti-RBD antibodies after the third dose of vaccine (A) and the level of anti-RBD antibodies before and after the third dose of patients in the mRNA-1273 group and the placebo group (B)

In terms of secondary indicators, the third dose of mRNA-1273 vaccine also promoted the production of neutralizing antibodies

▲The ratio of antibody neutralization activity before and after the third dose of vaccine in the mRNA-1273 group and the placebo group

The third dose of mRNA-1273 vaccine also stimulated patients to produce a stronger T cell response, with a higher count of new coronavirus-specific T cells (median 432 vs 67 per 106 CD4+ T cells)

▲The new coronavirus-specific CD4+ T cell counts of patients in the mRNA-1273 group and the placebo group after the third dose of vaccine (picture source: reference [1])

The third dose of mRNA-1273 was also well tolerated.

The research team pointed out in the paper that based on existing experimental evidence, the third dose of mRNA vaccine for organ transplant recipients can bring better immunogenicity and is safe

As for whether transplant recipients need to receive the third dose of vaccine routinely, NEJM editorial pointed out that although the third dose of vaccine brings hope to transplant recipients, whether the current small, short-term trial is sufficient to promote changes in practice is still a question mark

In the NEJM editorial podcast at the same time, Dr.

(The original text has been deleted)

Reference

[1] Victoria G.

[2] Winfred W.
Williams, Julie R.
Ingelfinger.
(2021).
Third Time's a Charm — Covid-19 Vaccine Hope for Solid-Organ Transplant Recipients.
The N Engl J Med, DOI: 10.
1056/NEJMe2112866

[3] Eric J.
Rubin, Lindsey R.
Baden, Stephen Morrissey.
(2021).
Audio Interview: Monoclonal Antibodies and Booster Shots.
The N Engl J Med, DOI: 10.
1056/NEJMe2113398

[4] What Makes the Newly Approved Drug for Depression So Different?.
Retrieved August 5, 2021, from https://