Prompted by the life-saving impact of messenger ribonucleic acid (mRNA)
vaccines during the COVID-19 pandemic, the World Health Organization’s (WHO)
Science Council has released a report reviewing the potential benefits and
limitations of mRNA vaccine technology. The report conveys the importance of research
and development (R&D) efforts to COVID-19 mRNA vaccines and outlines challenges
of inequitable access.
The success of mRNA COVID-19 vaccines resulted
from decades of investment in basic science exploring chemical modifications of – and immune responses to – RNA, with their potential
applications for HIV, respiratory syncytial virus (RSV), severe acute
respiratory syndrome (SARS), and cancer therapeutics and vaccines. Other key factors included thousands of people enthusiastically
volunteering to participate in clinical trials, collaborations between
researchers, and unprecedented levels of funding.
However, the benefits of the mRNA COVID-19 vaccines were not
distributed equally globally, with insufficient research and development
capacity, intellectual property barriers and ultra-cold-chain requirements as
well as high costs for low- and middle-income countries.
“Unlocking the potential of mRNA technology beyond COVID-19
vaccines will require robust research to address limitations head-on,” said Professor
Harold Varmus, Chair of the WHO Science Council, a Nobel Laureate and former
Director of the U.S. National Institutes of Health. “To improve mRNA vaccine
technology, future research should seek to seek to develop more
temperature-stable vaccines, increase how long protection lasts, and ensure
effectiveness against a diverse range of strains and variants.”
The report recommends a framework to assess the value of mRNA
technology in developing vaccines and therapeutics against other infectious
diseases. A framework could also help establish the technology’s potential role
in addressing cancer and autoimmune diseases.
To inform such a framework, the report maps out the clinical trial
status of mRNA vaccines in the most advanced stages of development. While the COVID-19 vaccines are the
only safe and efficacious preventive mRNA vaccines developed and approved for
human use to date, mRNA vaccines against cytomegalovirus (a common virus that
can threaten babies and those with a weakened immune system), influenza A and B,
and RSV are in Phase 3 trials. There is also on-going discovery work in
tuberculosis, malaria, HIV as well as noncommunicable diseases.
The report also calls for further research to address the
potential of this technology as well as its limitations. Improving the
stability of mRNA vaccines at higher temperatures should be a key target of
investment and research efforts. Another key recommendation is ensuring end-to-end
development and access by way of investment and applying lessons from COVID-19 initiatives,
such as the ACT-Accelerator, which worked to secure access to COVID-19 tests, treatments, and
vaccines.
“To maximise the impact of mRNA technologies, it’s vital to
promote and strengthen research, going country by country, so every region has
a dynamic and sustained scientific, research and development ecosystem,” said Dr
Jeremy Farrar, WHO’s Chief Scientist. “Coupled with investment and a commitment
to equitable access, a more diverse global research ecosystem will better
address communicable and noncommunicable diseases and improve health outcomes
with new safe and effective mRNA vaccines and potentially therapeutics for
all.”
The report also underscores the importance of building trust, and improved
communication around mRNA technologies to limit vaccine hesitancy and
misinformation and improve current and future vaccine uptake.
