While many of the first generation of COVID-19 vaccines may have been quick to make their way onto the market and pass regulatory hurdles, the fact that they target the spike protein that rests on the outer surface of the virus that infects human cells means that it can be significantly less effective – and possibly completely ineffective – as the virus continues to mutate. The omicron variant that is currently circulating has many more mutations than previous variants, with more than 30 mutations on its spike alone.
While researchers are still working to determine the extent to which the variant can evade immunity from the current vaccines, the fact that so many vaccinated individuals are coming down with it seems to indicate that they are not terribly effective. Early data on the Pfizer vaccine is already showing reduced protection against the variant, and it stands to reason that as the virus continues to evolve, the vaccines that address the first variant of the disease will continue to be less effective, underscoring the need to develop vaccines that target a part of the virus that is less susceptible to mutations.
The chief scientist of the World Health Organization, Soumya Swaminathan, said that next-generation vaccines are needed while speaking at the Reuters Next conference.
At the heart of the problem is the fact that most of the COVID-19 vaccines being used right now focus solely on the parts of the spike protein that spur a strong immune response but are most vulnerable to mutations. The mRNA vaccines that are overwhelmingly popular around the world right now had a 95% efficacy against symptomatic COVID-19 at first, something that brought developers billions of dollars in revenue.
There were just a few exceptions to this approach in early vaccines, and most did not perform well. For example, Sinovac Biotech's vaccine produced in China, which uses an inactivated version of the SARS-CoV-2 virus rather than singling out particular genes, loses its antibody protection quickly and has limited protection in older people.
Many vaccine makers are currently working on creating new versions of their current vaccines to target the omicron variant, but it is extremely difficult to keep up with the latest mutations and create an effective vaccine that offers people real protection before each new variant spreads.
Some research groups are already working on vaccines that offer broader protection against the virus, targeting the parts of the virus that are considered too essential to its survival to mutate. However, experts have warned that it could take a long time and significant funding for these efforts to succeed.
The Coalition for Epidemic Preparedness Innovations (CEPI) is funding Israel MigVax Corp, which is currently working on developing a variant-proof oral vaccine, as well as a potentially variant-proof vaccine under development by Saskatchewan's Vaccine And Infectious Disease Organization. They are also offering financial support to Gritstone Bio, which is working on a self-amplifying mRNA vaccine aimed at fighting variants.
Gritstone CEO Andrew Allen said: "It's just a little naive to think that the vaccines that we made in the first few hot minutes of the pandemic are the best vaccines that we can make."
It is important to continue drawing attention to the limitations of the current crop of vaccines, and while one can only hope that this could lead to the development of truly safe and effective options that offer long-term protection, this should also serve as a wake-up call that vaccines may not be the best option after all and that natural ways of boosting immunity and better treatment protocols are worthy of similar investments.
Sources for this article include: