A new follow-up study discovered that the Moderna mRNA vaccine and a protein-based vaccine candidate containing an adjuvant, a substance that boosts immune responses, continue to protect rhesus macaques against lung disease one year after they were vaccinated as infants.

The experimental COVID-19 vaccine offers long-term protection
A Rhesus Macaque (Macaca mulatta)
(Photo : SAM PANTHAKY/AFP via Getty Images)

In 2021, a team of scientists led by researchers from the University of North Carolina at Chapel Hill, Weill Cornell Medicine, and NewYork-Presbyterian reported that the Moderna mRNA vaccine and a protein-based vaccine candidate containing an adjuvant, a substance that boosts immune responses, elicited long-lasting neutralizing antibody responses to SARS-CoV-2 during infancy in pre-clinical studies, as per ScienceDaily.

A year after they were vaccinated as infants, the 2-dose vaccines still provide protection against lung disease in rhesus macaques, according to a follow-up study published in Science Translational Medicine.

Kristina De Paris, Ph.D., professor of microbiology and immunology at the UNC School of Medicine, Sallie Permar, MD, Ph.D., chair of the Department of Pediatrics at Weill Cornell Medicine, and Koen K.A. Van Rompay, DVM, Ph.D., leader of the Infectious Disease Unit at the California National Primate Research at the University of California, Davis, are the paper's co-senior authors.

Emma C. Milligan from the UNC School of Medicine's Children's Research Institute and Katherine Olstad from the California National Primate Research Center are co-first authors.

To assess the efficacy of SARS-CoV-2 infant vaccination, the researchers immunized two groups of eight infant rhesus macaques at the California National Primate Research Center at two and four months of age.

Each animal received one of two vaccines: a preclinical version of the Moderna mRNA vaccine or a vaccine combining a protein developed by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, with a potent adjuvant formulation.

The adjuvant formulation stimulates immune responses by engaging receptors on immune cells and consists of 3M's molecular adjuvant 3M-052 formulated in a squalene emulsion by the Access to Advanced Health Institute (AAHI).

According to Dr. De Paris, the adjuvanted protein vaccine candidate maintained higher levels of neutralizing antibodies and provided superior protection compared to the mRNA vaccine.

These findings imply that these vaccines are both safe and effective when administered to young infant macaques.

Furthermore, the findings will aid in the optimization and development of SARS-CoV-2 vaccines, potentially reducing the need for frequent boosters and protecting vulnerable populations such as young children.

Young infants are one of the most vulnerable pediatric populations when it comes to COVID-19.

This fall, we are seeing a significant increase in hospitalizations for respiratory virus disease in infants due to a confluence of SARS-CoV-2, flu, and RSV circulation, according to Dr. Permar, who is also the Nancy C. Paduano Professor in Pediatrics at Weill Cornell Medicine and the pediatrician-in-chief at NewYork-Presbyterian Komansky Children's Hospital. We should take every opportunity to provide our youngest patients with safe and effective vaccine immunity, including considering COVID-19 vaccination earlier than the currently recommended 6 months of age.

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COVID-19 Vaccines Are Effective

COVID-19 vaccines were approved for emergency use in the United States for the first time in December 2020, as per CDC.

Following vaccination, studies revealed that the vaccines provided approximately 90% protection against symptomatic infection, severe illness, and death.

Scientists saw decreased vaccine effectiveness against infection by July 2021 as new variants emerged, and the CDC recommended that masking continue, even for people who had received a primary series.

More than 20 ACIP meetings have publicly reviewed data on vaccine effectiveness and provided real-time data demonstrating COVID-19 vaccines and boosters remain highly protective against severe illness and death in the months since, in the context of updated vaccine booster recommendations.

Importantly, the rates of COVID-19-related hospitalizations and deaths are significantly higher among unvaccinated adults than among those who have received a primary series and are up to date with recommended COVID-19 vaccination, particularly among adults over the age of 65.

The current vaccines provide less protection against symptomatic infection and transmission than against severe disease and diminish over time, particularly against currently circulating variants.

 As a result, it is critical to stay current, especially as new vaccines become available.

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