This is the first article in a four-part series about the coronavirus. The second article will look at the anti-vaccine movement.
“Vaccines save lives; fear endangers them. It's a simple message,” observed Jeffrey Kluger, a senior writer at Time magazine.
The world is currently stricken with the COVID-19 pandemic, which has significant mortality rates. Hard lockdowns or softer measures including social distancing clearly slow the spread, as we have seen here in Malta. Drugs are also being tested to reduce the severity of infection, but the only way to actually prevent the disease is a vaccine.
All vaccines work by presenting part or all of the pathogen to the human immune system (in an injection or oral drops) and this prompts protective antibody formation by the body’s white blood cells.
At this point in time, around 80 companies and academic institutions are racing to produce a vaccine and five are already in the human testing phase. This is thanks to rapid genetic sequencing technology and the fact that virologists and vaccinologists have predicted and modelled potential pandemic viruses, including coronaviruses and not just the influenza virus.
Moreover, the medical community was already wary of coronaviruses which caused two other recent epidemics: Severe Acute Respiratory Syndrome (SARS) in China in 2002-04, and Middle East Respiratory Syndrome (MERS), in Saudi Arabia in 2012. Work on vaccines had commenced in both cases but halted when the outbreaks were contained.
Vaccines are tested in clinical trials prior to regulatory approval, in three phases. The first uses a few dozen healthy volunteers and tests for safety and side effects. The second involves several hundred people, usually in a part of the world affected by the disease to check how effective the vaccine actually is. The third phase is just like the second, but involves several thousands.
Not all vaccines pass these phases as they may be found to be unsafe and/or ineffective. Moreover, vaccines may have unexpected effects. For example, a vaccine that was produced in the 1960s against Respiratory Syncytial Virus (one of the viruses that causes the common cold and respiratory distress in babies) was found to actually aggravate these symptoms in infants who contracted the disease. It is for these reasons that a vaccine candidate usually takes 10 years from inception to regulatory approval.
Seth Berkley, the CEO of global health partnership GAVI (Global Alliance For Vaccines and Immunization) however noted that "for Ebola, we did it in five years, I know we can accelerate that". Nevertheless, even considering the extreme urgency of the current situation we find ourselves in, “like most vaccinologists, I don’t think this vaccine will be ready before 18 months,” says Annelies Wilder-Smith, Professor of Emerging Infectious Diseases at the London School of Hygiene and Tropical Medicine.
And once a vaccine is ready, there are two more logistical problems: the production of several billion doses (and the creation of manufacturing plants) and global vaccine distribution and administration. These are no mean feats, but governments worldwide will certainly step in and help if needed. Prioritisation will also have to be made so as to first protect those at higher risk, such as health care workers and the vulnerable groups.
As the New York Times succinctly summarised: “Lockdowns will end haltingly, immunity will become a societal advantage and many more Americans than the White House admits will die. Until a vaccine or another protective measure emerges, there is no scenario in which it is safe to come out of hiding.”
Professor Wilder-Smith also observed that due to the rapid spread of the virus, the pandemic “will probably have peaked and declined before a vaccine is available.” However, a vaccine would still be needed especially if the virus continues to circulate continually or seasonally (like influenza) and if it is possible to contract the virus more than once.
In the interim, the Maltese Paediatric Association (backed by the World Health Organisation) has reiterated that with regard to routine immunisation services, and disruption “even for short periods, will result in an accumulation of susceptible individuals, and a higher likelihood of vaccine-related outbreaks … may result in deaths and an increased burden on health systems already strained by the response to the COVID-19 outbreak.”
Victor Grech is a consultant paediatrician (Cardiology) at Mater Dei Hospital