By Mark A. Kelley, MD |2/5/18
Founder, HealthWeb Navigator
The current flu season is the most severe in nearly a decade. In a typical year, influenza causes 3 to 5 million cases of severe illness, and anywhere from 290,000 to 650,000 deaths around the globe.
But this year may be even more worse because the flu vaccine has been only 10-20% effective in preventing the flu—less than half its usual protection.
The flu virus mutates rapidly, so creating an effective vaccine is largely a game of chance. The process requires scientists to decide in advance which strains they think will be the most prevalent each flu season. That decision determines how the flu vaccine is manufactured, a process that takes about six months.
This year the H3N2 virus emerged unexpectedly. It is particularly nasty and tends to be more resistant to flu vaccines.
The flu virus, particularly type A, can also blend its genes with other viruses, including those infecting animals like pigs and birds. These changes produce new surface coatings on the virus, which pose a major challenge for our body’s defenses. If our immune system recognizes a virus from a previous infection or vaccine, it can quickly kill it. However, new forms of the virus are hard to recognize and can make it difficult for the immune system to react quickly. Such a delay can be deadly if it allows the infection to gain a foothold.
Compared to vaccines for polio, smallpox, and measles, the current flu vaccine falls considerably short:
• It offers limited protection that changes year to year.
• It does not provide lifelong immunity.
• It is unlikely to protect against more dangerous strains of flu like the 1918 pandemic that killed 50–100 million of the world’s population.
Can we produce a better and more effective flu vaccine? The short answer is yes—but only if we have the will to do it.
Scientists have known that certain parts of the flu virus do not change their genetic profile. These areas hide from our immune system. A more effective vaccine would expose and target those areas so that our immune system can always recognize the virus and eliminate it. Other approaches include reengineering some of our own cells to look like the flu virus and making the immune system better prepared to reject it.
These and other innovations are aimed at developing more effective and predictable protection against the influenza virus. Although it will likely take years and considerable funding to develop, the costs are paltry compared to the estimated $8.4 billion in lost productivity every year in the U.S. resulting from the flu. A new vaccine that uses modern technology and offers better protection would be a bargain.
Influenza has plagued mankind for centuries. Every winter, this disease reappears around the world. It may spread even more rapidly with population growth, international travel, and urbanization.
There are reasons to be optimistic about a new vaccine. In this era of “precision medicine,” the science of virus biology has advanced far beyond the 70-year-old technology used for the current vaccine. If the nations of the world choose to accept this challenge, we may be able to protect millions of people who suffer or die from influenza every year.