• Although the currently available COVID-19 vaccines are highly effective, limited manufacturing capacity and the need for cold-chain storage hinder their global distribution.
  • A recent study tested the efficacy of a new adeno-associated virus (AAV) vector-based vaccine in mice and macaques.
  • A single dose of the AAV-based vaccine provided protection against SARS-CoV-2 infection in macaques and elicited a potent immune response against the virus for at least 11 months.
  • The vaccine was stable at room temperature for 1 month and could potentially be manufactured on a large scale using established processes.

While nearly 42% of the global population have received at least one dose of a COVID-19 vaccine, only 1.9% of individuals in low income countries have received at least one vaccine dose.

This inequitable distribution is, at least partly, due to the limited supply of vaccines and the stockpiling of vaccines by rich nations.

With the successful vaccination of a substantial proportion of the population in wealthier countries, the supply and distribution of vaccines to middle and low income nations are improvingTrusted Source.

However, despite the increase in the supply of the vaccines that provide a high degree of protection against COVID-19, the vaccines do have limitations.

The current COVID-19 vaccines includeTrusted Source mRNA vaccines, such as the Pfizer-BioNTech and Moderna vaccines, and adenovirus vaccines, such as the Oxford-AstraZeneca and Johnson & Johnson vaccines.

All of these, except the Johnson & Johnson vaccine, involve a two-dose regimen, and many of them require storage at cold or ultracold temperatures.

The finite global manufacturing capacity and the lack of the necessary cold storage infrastructure in low income countries are some of the major challenges impeding the global supply and availability of vaccines.

This, along with the emergence of new SARS-CoV-2 variants and the uncertainty about the duration of protection the currently available vaccines provide, suggests the need for new, durable, and easily deployable vaccines.

To address these concerns, a group of researchers is developing a vaccine candidate using an AAV as a vector.

Authors of a recent study, which appears in the journal Cell Host & Microbe, found that a single dose of a vaccine candidate AAVCOVID-1 (AC1) elicited an immune response against SARS-CoV-2 for at least 11 months in macaques. The vaccine candidate was also stable at room temperature for 1 month and produced an immune response against current variants of concern.

Lead author of the study, Dr. Luk Vandenberghe, associate professor at Harvard University and director of the Grousbeck Gene Therapy Center in Boston, MA, told Medical News Today:

“COVID-19 is a continued global health concern for which a number of highly effective vaccines are available to mitigate the pandemic. The data on our experimental vaccine shows that it has the potential to address two of the remaining concerns that prevent effective management of the situation.”

“First, vaccines need to be available for effective deployment worldwide: our data indicates AAVCOVID to be a single-dose vaccine with room-temperature stability to facilitate vaccine campaigns effectively. Second,” Dr. Vandenberghe continued, “our animal data indicates a durability of the immune response that is generally thought to be leading to protection from disease.”

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