COVID-19 — Important considerations for developing and using a vaccine

ABSTRACT

The novel coronavirus SARS-CoV-2 after emerging in China has caused a global pandemic that is risking the lives of millions. COVID-19 has spread across the world at a very rapid rate raising concerns of capacity limitations and lack of unified responses at the global level, particularly from the world’s most developed countries. The spread of further infection has been curtailed by lockdown and mass social distancing that has been enforced in most parts of the world. There are no clinical data yet suggesting that any available candidate vaccine will be effective for COVID-19 which will be a critical need for eventually preventing this disease. Extensive research is underway with some success in identification of monoclonal antibodies from COVID-19 recovered patients, which may inform on vaccine development. The clinical evaluations of COVID-19 vaccines need to follow standardized protocols that are essential for safeguarding humans. In absence of a vaccine or a widely available effective therapy, quarantine and other preventive measures are essential in curtailing the risk of pandemic spread.

KEYWORDS:

• Coronavirus
• SARS-CoV-2
• COVID-19
• global pandemic
• vaccine

Background and epidemiology

A novel virus was identified during December 2019 named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).^1–4 From what initially looked like a localized outbreak in China, the COVID-19 spread rapidly and the pandemic potential of this virus was clear as declared by the World Health Organization (WHO). The outbreak has spread to essentially all countries.⁵ Globally, hundreds of thousands of people have died and millions of confirmed infected individuals have been reported. On the brighter side, infected individuals have recovered from COVID-19, and the rate of recovery is on the rise.⁶ Despite some progress, no vaccine has been developed against the pandemic virus⁷ and nations are trying to restrict the COVID-19 outbreak by confinement, wider lockdown and mass social distancing in parts of the world to curtail the virus spread.

COVID-19 and developing nations

This “one-size-fits-all” approach of fighting the viral disease could be least effective or even counterproductive and catastrophic in poor countries. In high-income countries, social distancing measures have been in place to reduce the number of new infections, thereby supporting the capacity of the healthcare systems and which is predicted to save many lives.⁸ On the contrary, consider a country like Pakistan with a population of over 220 million – which has a doctor-patient ratio of approximately 1:1100;⁹ and 2000 ventilators; the imposed lockdown could have adverse effects and potentially endangering more lives than it would save. There is a worse situation in conflict zones and refugee camps around the world where social distancing is essentially impossible. COVID-19 is wreaking havoc on weak healthcare systems and livelihoods in low-income countries, many of which have very high levels of debt; while high-income countries have shown the ability to devote billions of dollars to keep their economies alive.⁸ Even though the COVID-19 pandemic represents a serious global threat, the impact and capacity of countries to respond and to endure costs varies greatly, and pressures on low-income countries are immensely high.^8,10 Highly ambitious plans to overcome this crisis are warranted, and testing and treatment (whenever available) ideally should be made available free to people everywhere. Furthermore, developed vaccines must be made rapidly available to everyone and with costs subsidized through aid from high-income countries and donor organizations, all within the constraints of the capacity to manufacture the very large number of doses needed worldwide.^10,11

Efforts to develop a vaccine for COVID-19

Scientists in pharmaceutical and biotech companies and academic institutions across the world are working intensively on vaccine development.¹² Effective antibodies that were developed against the SARS during 2012 have been used in animal trials against SARS-CoV-2.¹³ Before the use of COVID-19 vaccine is allowed in humans, standard protocols are essential for safeguarding subjects. To assess safety with a wide range of virus strains, animal models should be used to provide preclinical evidence for efficacy, which will delay clinical trials of vaccines for months. Testing vaccines without standard protocols for evaluating their side effects and risks could bring unjustifiable hindrances during the ongoing pandemic, and more seriously in the future. BioThrax was the first vaccine that received approval following the US Food and Drug Administration’s (FDA) Animal Rule.^14,15 Moreover, the rule qualifies approval on the basis of adequate and well-controlled animal studies that infer clinical utility.¹⁴ According to the WHO, the fatality rate of COVID-19 is cumulatively ~7%, but this rate varies widely around the world (e.g., >10% in Italy). More importantly, the transmission rate is significantly higher which means that the population living in the COVID-19 hotspots need vaccination as soon as possible in future years to control future outbreaks. Monoclonal antibodies have been identified from COVID-19-recovered patients with ‘strong’ ability to bind with viral proteins¹⁶ and it is likely that until vaccination is available, these antibodies could be used effectively in advanced disease cases. Once a vaccine will have been approved against COVID-19, a further set of challenges will present themselves. For instances, how or when would it be available or who to be vaccinated first? The amount of vaccine needed for COVID-19 will be massive for future years. Secondly, the COVID-19 pandemic has already wreaked havoc on the international economy, so it is important to assure that the vaccine reaches all, including the economically needy. Thus, organizations like the WHO must provide guidelines on this aspect before a vaccine becomes available.

Conclusion

COVID-19 has caused a pandemic with a very high transmission rate. Since, the time to curtail spread of SARS-CoV-2 is limited, development of vaccines is crucial to aid the control of the disease. Resources of both developed and developing countries have been stretched by COVID-19, with resource limitations and shortfall being more acute in populous and vulnerable developing countries, with impact that will be long-lasting even for those who did not contract the disease. Furthermore, COVID-19 has highlighted the gaps in public health preparedness at the global level, and infectious disease outbreaks as evident from COVID-19 are global concerns and poses risk everywhere. Therefore, holistic and integrative international efforts and collaboration are required to meet this global challenge. In lieu of an antiviral treatment or approved vaccine for COVID-19, lockdown and social distancing has worked to an extent. The development of vaccine against this pandemic is indispensable, while efficacy will heavily rely on following standardized protocols applied prior to and during clinical trials.

Disclosure of potential conflicts of interests

No potential conflicts of interest were disclosed.