The coronavirus, and the COVID 19 syndrome it causes, has emerged as the single most significant global pandemic in recent history.  Fueled by its high transmissibility and our highly connected world, this infection continues to ravage our planet.  COVID 19 has highlighted the vulnerability of aging populations to new and emerging infectious diseases.  The race is on to develop a vaccine to end this pandemic, which threatens to kill millions of people, especially those in aging populations. To be sure the scope of this problem is clear, the United Nations projects that by 2050 there will be twice as many over the age of 65 as there are children under 5 and the number of people age 65 or older globally will surpass the number of people 15 to 24 years of age.

Even as we look to develop vaccines and therapies for COVID 19, we are traveling blind relative to our own immune system. This is especially true of the aging population whose immune status declines with time.  Numerous studies have shown that our immune status declines with time, and this includes our ability to respond to vaccines.  Some vaccines work extremely well, such as the shingles vaccine which is 90% effective in those over 70 years old.  Many older patients are not well-protected by other common vaccines, including influenza.  What accounts for this variability and what will be the effectiveness of any new corona vaccine on the elderly?  That story is yet to be written.