Humoral response against spike protein and fifth and sixth COVID-19 mRNA vaccine in the uninfected and infected subjects: What should be for the seventh dose?

KEYWORDS:

• COVID
• vaccine
• humoral
• response
• dose

Dear Editor, we would like to share ideas on the publication “Humoral response against spike protein enhanced by fifth and sixth COVID-19 mRNA vaccine in the uninfected and infected subjects.”¹ The study’s shortcomings, as mentioned in the first paragraph, include a lack of information about the specific mRNA vaccine used, a small sample size, and a focus on only one type of antibody (S-IgG titers). Furthermore, the study does not provide information on the immune response’s durability or the effectiveness of the additional vaccinations in preventing COVID-19 infection or severe disease.

The fifth and sixth doses of the COVID-19 mRNA vaccine may increase antibody titers in people who have never been infected, according to the study. Those who received five or six doses had significantly higher geometric mean S-IgG titers than those who received fewer doses. This finding lends support to the idea that additional vaccinations can boost the immune response in people who are not infected, potentially leading to better protection against COVID-19. We must not dismiss the possibility of confounding effects due to genetic backgrounds,^2,3 as well as the possibility of unrecognized asymptomatic COVID-19⁴ in the “non-infected group” in this study.

It should be noted, however, that the focus of this study was on antibody titers rather than the clinical efficacy of the additional vaccinations. It makes no mention of the potential benefits or risks of repeated vaccination, such as adverse reactions or long-term effects. As a result, more research is required to determine the precise utility of the fifth and sixth doses of the COVID-19 vaccine in terms of immunogenesis and clinical outcomes. In fact, this study may lend support to a recent article on the benefit of the sixth dose of COVID-19 vaccine in stimulating effective immune response in transplant recipients.⁴

The decision whether to administer a seventh dose is a complicated one that must take into account a number of factors. Additional doses should be administered based on emerging scientific evidence, such as data on vaccine effectiveness, immune response, safety, and the prevalence of new variants. Given the current study’s findings that the positivity rate of nucleocapsid antibodies, indicating a history of COVID-19, decreased 82% and 30% of COVID-infected cases after 180 and 360 days of infection, respectively,¹ the seventh dose of the vaccine should still play a role in boosting immunity. It is critical to weigh the benefits and risks, as well as potential ethical concerns, such as ensuring equitable global access to vaccines. Based on the available evidence, government health authorities and regulatory agencies will need to make informed decisions on booster doses in consultation with experts.

Authors’ contribution

SW 50% ideas, writing, analyzing, approval.

VW 50% ideas, supervision, approval.

Findings

Regarding the study mentioned in the question as “THE EXPECTED SEROPROTECTION RATE AFTER THE SIXTH DOSE OF THE COVID-19 VACCINE: A NOTE FROM A CLINICAL MODEL ON KIDNEY TRANSPLANT RECIPIENTS,” it is not clear how this specific study relates to the findings mentioned in the first paragraph. Without further information or a detailed summary of the study, it is difficult to determine if it supports or aligns with the findings of the first study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.