Two comprehensive review papers in this week’s issue of NATURE magazine have encouraging news for us.[1],[2] One summarized the extent of this pandemic: 30 million people in 215 countries are affected, with a death rate of almost a million as of September of this year.
Experts pointed to several animal models available for testing vaccines and antiviral medications.1 This is a welcome development, because studying the infection in animals also helps us to understand the mechanisms the virus uses to cause damage. Not all animals are affected in the same way as humans, but there are enough similarities to provide us with important clues about how to treat sick patients. Interestingly, male and older non-human primates have more severe disease—just as is the case with us.
Vaccines are appearing with remarkable speed. As soon as we understood the RNA of the virus, vaccine development began at the beginning of this year.2 The effort is unprecedented. More than 180 vaccines are being tested: 47 have already passed through preliminary efficacy and safety testing, and 10 are currently being tried in large groups of patients to prove safety, efficacy and the duration of immunity. Among these are vaccines with inactivated virus, some with live but weakened versions of the virus, others target the spike protein of the virus with which it attaches to our cell membranes to enter the body, and viruses whose RNA have been altered so that they are no longer infectious. Different vaccines vary in their effectiveness; the best preparation is still to be identified.
The short- and long-term safety of the vaccine and the duration of immunity to infection are still to be established, but it is likely that by the end of this year, a promising candidate will be identified. How well and how quickly we can manufacture enough to supply Americans as well as other countries’ populations, and whether or not vaccine use will be widely accepted by those to whom we offer it, remain to be established.
[1] Munoz-Fontela C et al. Animal models for COVID 19. Nature 586..509.October 27, 2020
[2] Krammer, F. SARS-CoV-2 Vaccines in development. Nature 586. 516.October 22, 2020
Specialist in internal medicine and primary care.