by Deepak Asudani, MD, MPH, FHM
Whether it is the prompt and expeditious international collaboration to develop an Ebola vaccine, or tardy but promising development of the first anti parasitic malarial vaccine or the fascinating technology utilizing synthetic DNA for vaccine development against MERS, these developments promise to highlight significant strides in vaccine development for both established infections and newer and emerging infections. From a global health perspective, the recent news surrounding the development of vaccines against some of the infections has stirred rejuvenated excitement. Besides having the potential to save millions of lives, it is fascinating and compelling to see several technological advances that go into developing these vaccines.
While the promise of the Ebola vaccine comes in an astonishingly short time of within a year, the malaria vaccine has been in the pipeline for long 27 years unleashing the first reasonably effective anti-parasitic vaccine. The promise of synthetic DNA MERS vaccine lies in the technology that can be exploited for several other infections that will need vaccine development expeditiously. Let’s briefly examine these three vaccination efforts.
Ebola vaccine: Around this time last year, the world was gripped with the fear of the spread of Ebola and most media had only to tell about the morbid news of the devastation caused by Ebola infections. Ebola did in fact claim over 11,000 lives of the 28,000 plus global infections. Fortunately, the news pertaining to Ebola have changed this year; the epidemic appears not only to have momentarily ceased, but also the infection rates have decreased. In unison, the world took up arms against Ebola and took the right first step by containing the infection and preventing further spread. Next we ramped up efforts to expedite infection prevention with vaccination and curative treatments. Not long ago, the media were abuzz with astonishingly successful development of Ebola vaccine which holds the promise of changing the associated morbidity and mortality from Ebola infections.
The VSV-EBOV developed by the Public Health Agency of Canada in association with other collaborators utilized the trial vaccine in over 4,000 close contacts of around 100 Ebola patients Link. The close contacts were administered the trial vaccine and the results were a big hoorah with vaccine efficacy of 100%. Whether or not this 100% efficacy rate can be translated in larger demographics and outside of the ring vaccination approach remains to be seen.
But there is no reason to not to be excited about this development. The development utilized a small amount of viral genome to synthesize the vaccine and induce immunity in the at risk population. It is an exciting time to see a widespread international participation and partnership to develop a highly successful vaccine. The relentless effort by every stakeholder is a testimony of the collaboration that can exist if a preventive or curative approach is sought.
Malaria vaccine: The next success story (kind of) is that of the malaria vaccine – the development and regulatory approvals for the vaccine have been tardy. In a stark contrast to the Ebola vaccine, Mosquirix also known as RTS, S has been in incubation for a really long time. Even after such a marathon R&D run, the efficacy of the malaria vaccine is just marginal. Thirty years and a global economic burden of billions of dollars and significant mortality later, we have a vaccine that is only about 30% effective. The effectiveness of the vaccine does not sustain forever and wanes overtime making the logistics of delivering the vaccine with its sustained benefits.
However, let’s not give up hope. A 30% effectiveness in populations effected by malaria is still a large number. Besides, the vaccine Mosquirix developed by PATH Malaria Vaccine Initiative, supported by the Bill and Melinda Gates Foundation and others deserves a high 5 for being the very first vaccine developed against the parasite. Several arguments also abound about global tardiness and lack of political willingness in developing anti-malarial vaccines. This certainly appears to be in stark contrast to Ebola vaccine development. Again, despite its low efficacy and the tardiness in development, the vaccine deserves celebration. In the meantime the vaccine is waiting regulatory approvals and it’s anticipated that it will be available for use in 2016.
MERS- CoV vaccine: The MERS-CoV Corona Virus Infection that was first reported in 2012 has become more widespread and over 24 countries have been impacted by the infection. From vaccine development frontier several candidates are in the pipeline.
The first is a synthetic DNA based vaccine that targets MERS-CoV has been developed through a collaboration between NIAID and University of Pennsylvania researchers among several others. There have been some exciting results from the pre-clinical results. The vaccine seems to be working remarkably well in protecting rhesus macaques from developing symptoms of the disease when administered. Also notably the vaccine has the ability to elicit antibodies against the spike protein of the virus in camels which is understood to be the mode of spread of this pathogen among humans (Science Translational Medicine). The use of synthetic DNA is rather a novel and innovative approach to vaccine development
The techniques of synthetic DNA-based MERS vaccine development can potentially be translated to other serious infections including dengue, Ebola, hepatitis B, influenza, HIV, and many more in the future. The potential of synthetic DNA based vaccine needs to be explored fully and the promises on the horizon are many.
In a globalized world where people move rapidly from one place to another, the threat of an outbreak or pandemic is more imminent. It’s exciting to see that the field of vaccine development has gained significant momentum with promising gains and new approaches to tackle serious infections. The recent success of the field of vaccine development can be attributed to expeditious international collaboration, new approaches in vaccine development, and expanding the scope of vaccine for parasitic infections. 3 cheers for these recent successes and I look forward to the day that these vaccines clear regulatory hurdles and are available for public and greater use.
Dr. Deepak Asudani MD,MPH, FHM works as an academic hospitalist at the University of California, San Diego at Hillcrest Medical Center, San Diego and Thornton Hospital, La Jolla. Prior to moving to San Diego, he was a faculty physician at Tufts University and worked at Baystate Medical Center, Springfield, MA.
Currently, he serves on the SHM Public Policy Committee and has an interest in policy analysis, health disparities, diversity and inclusion, and global health. He is actively engaged in house staff education and international medical education. At UCSD Hospital Medicine, he directs Global Health Initiatives, and is involved in developing educational programs for international students including their clinical training and simulation experiences.
Dr. Asudani attended medical school at Rajasthan University, Jaipur, India and completed his residency in Internal Medicine at New York Medical College- Metropolitan Hospital Center in New York. He received his Masters in Public Health from University of Massachusetts, Amherst.
Outside work, he enjoys painting, playing cricket, going to the beaches and most of all spending time with his family. He lives in San Diego (and does not plan to move) with his wife and two beautiful kids.