A safe and effective vaccine against Covid-19 is of utmost priority in this current pandemic. People around the world may return to normal life when a successful Covid-19 vaccine is available for public use.
Because of increasing demand, in many countries, experts are pushing hard to be successful in developing a vaccine within a short period of time. Similarly, Globe Biotech Limited in Bangladesh has recently proposed a possible vaccine candidate(s) based on preclinical studies conducted in vitro and in mice.
It is encouraging in the context of research in Bangladesh where resources are limited. However, a successful vaccine will be administered in millions of healthy humans. Therefore, a vaccine must meet the finest quality possible, which comes through the completion of extensive laboratory experiments with strong data sets that must meet the international scientific and regulatory standards before the vaccine may enter human trials.
Therefore, the focus of preclinical studies is to ensure that a vaccine candidate meets the required quality; that it is safe and generates protective immune responses before human trials may begin. Under those criteria, we, a group of scientists self-volunteered to evaluate the vaccine candidate of Globe Biotech Limited in an unbiased manner. Is the vaccine candidate of Globe Biotech showing promising data to qualify for Phase I clinical trial?
Why is the safety of a vaccine a matter of serious concern?
Vaccine could be seen as something like a double-edged sword as it can save lives. On the other hand, it can also kill people if the safety is not ensured.
Unlike any drug, vaccines are usually administered in a large number of healthy people, usually around 70-80% of the total population in a country. If anything goes wrong in terms of safety, millions of healthy people may become sick and/or die.
That is why international regulatory agencies such as the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) with a highly skilled multidisciplinary expertise are established to review and monitor all steps of a vaccine development for ensuring quality, efficacy, and safety of a vaccine.
Scientific review of the BANCOVID candidate vaccine
There are three critical aspects that need to be fulfilled to develop a vaccine: quality, safety, and efficacy.
Quality aspects of a candidate vaccine
1. Are all components required for BANCOVID development, namely mRNA and lipid nanoparticle (LNP), manufactured in an internationally certified GMP facility at Globe Biotech?
Well-developed international guidelines are in place to ensure quality. For instance, production of the vaccine candidate which is injected into animals must fulfil the GLP and GMP compliance. All of the issues have to be ensured before initiating a human trial.
2. Has Globe established a manufacturing process to consistently produce GMP grade mRNA-LNP with the exact particle size to be injected in humans?
The vaccine is expected to be produced for many years to come and therefore consistency of the vaccine manufacturing process must be nearly 100%. Batch variations must not be acceptable. Globe BANCOVID preprint has mentioned: "The 444 mRNA was encapsuled in lipid nanoparticle (LNP) ranging from 60-140 nm with the final pH of 7.2. We did a pilot study with limited numbers of mice to identify the suitable mRNA-LNP size for our formulation. mRNA-LNP either smaller than 70 nm or larger than 110 nm did not generate considerable immunological response even with a dose of 10 ng/mice (data not shown). To obtain the best process control for the dose production, we, therefore, set our mRNA-LNP size range at 85±10 nm. We used mRNA-LNP of this range throughout the rest of the experiments."
Now it is a vital question whether Globe has established a manufacturing process to consistently produce GMP grade mRNA-LNP with the exact particle size. All the reagents used for mice experiments must not be used for clinical batches (i.e. for clinical trials). And therefore, Globe Biotech needs to show GMP-grade and consistent manufacturing process of the vaccine candidate if the preclinical data show any indication to begin next phase.
3. Has the stability of Globe Biotech's vaccine evaluated?
The World Health Organisation (WHO) has set clear guidelines to evaluate the stability of a vaccine as the vaccine must keep its required potency throughout the whole shelf-life of a vaccine which can be up to two years. Instability of mRNA particularly poses additional concern, which needs to be carefully evaluated for vaccine candidate of Globe Biotech.
Safety and efficacy of Globe Biotech's vaccine candidate
1. Regarding the vaccine formulation, the FDA recommends performing the non-clinical toxicity studies using the same lot as proposed for the clinical trial. If this is not feasible, the FDA recommends that non-clinical lots will be comparable to clinical lots with respect to physico-chemical data, stability, and formulation and be manufactured in accordance with applicable cGMP standards. It is crucial to ensure that Globe Biotech has performed their mice experiments following such regulations.
2. The ICH Guidelines require that a vaccine must be studied in dose selection and repeat-dose toxicity studies including immunotoxicity and safety pharmacology in more than one species. Moreover, plasmid biodistribution, persistence, and theoretical risk of vector integration must be studied.
It has to be noted that such studies are not available in the preprint manuscript of Globe Biotech. Globe Biotech performed studies using mice alone with the proposed vaccine candidate and showed some clinical correlates to support the vaccine safety.
Importantly, similar to other mRNA vaccine candidates, namely Moderna/NIH and BioNTech/Pfizer, Globe Biotech must perform nonhuman primate studies for vaccine safety as well as efficacy before entering the Phase I clinical trial.
As for reference, most of the front-line vaccine candidates against Covid-19 have gone through testing in two or three higher animal models in order to have solid data on vaccine safety and efficacy. While basic non-clinical immunogenicity and protection can be done in a non-GLP environment, toxicity studies must be conducted in GLP compliance (+ regional animal ethics). Globe Biotech has not fulfilled those very critical requirements according to the data available in the public server.
3. The WHO has established clear guidelines on nonclinical evaluation of vaccines. Among hundreds of various aspects associated with the guidelines, the WHO recommends that "For small animal models, e.g. rats and mice, it is recommended that approximately 20 mice (10 males + 10 females) per group be studied."
According to the preprint, Globe did use only six mice (three males + three females). It is expected that a total of 100 mice should have been injected for BANCOVID. But Globe used only 30 mice. Therefore, Globe did not categorically follow the WHO guidelines and the data generated from animal experiments come into serious question.
The approach that is scientifically acceptable in the field is that each observation (research experiment) whether performed in vitro or in vivo must be repeated independently in a similar condition using the same number of animals. The data must be reproduced for any conclusion that authors inclined to provide. Unfortunately, Globe's pre-print manuscript has no documentation in this aspect and data cannot be reliable.
In addition, because of the concerns of the experts during high speed Covid-19 vaccine development, many vaccine developers including Moderna/NIH, BioNTech/Pfizer, Janssen Pharmaceuticals, and Oxford/AstraZeneca have published their non-clinical studies in top-ranked journals to show the quality of their data while Globe Biotech has not published their studies yet in any peer-reviewed journal.
Does Globe's vaccine candidate induce optimal immune response in the preclinical studies?
Vaccine-induced immune responses and its relevance in protection of animals are other critical elements to evaluate during preclinical studies. Globe Biotech should keep in mind that vaccine efficacy at preclinical stage remains the gold-standard in order to go to the next level, Phase 1 clinical trial. The claimed preclinical data of Globe Biotech are very poor in the sense of data quality, immunogenicity as well as efficacy.
1. Candidate vaccine of Globe Biotech induces antibodies which they have claimed to be important due to D614G mutation in Covid-19, which actually has not been further characterised by testing against any pathogenic strains of SARS-CoV-2 with D614G mutation. Most importantly, the candidate has not been tested against any available SARS-CoV-2 strains isolated from infected patients. Therefore, the novelty that they claimed is highly questionable.
2. The response which Globe has claimed Th1 balanced is also based on vague antibody classes. This idea is already outdated and not acceptable in the field. On top of that, their data do not show significant change by the ratio of antibody class switch (0.8 is negligible).
3. Neutralisation assay was done using recombinant pseudo virus, which people often do. But such a preclinical study was done without in vivo challenge using SARS-CoV-2 strain isolated from patients. It is premature to make a solid claim that antibody responses were enough to prevent SARS-CoV-2 infection.
4. T cell data in their pre-print is simply not showing any response. Globe Biotech just has claimed it as Th1 response. This data need to be checked by expert immunologists before sending for publication. Data quality, flow cytometry gating on specific population and the cytokines that they measured – none of those is done in the way that a standard immunology lab does in this present time.
Most importantly, Globe Biotech has exaggerated highlighting the specificity of their vaccine targeting the D614G mutation. In fact, D614G mutation is outside the receptor binding domain (RBD) and hence does not need to be focused in developing a Covid-19 vaccine. Globe Biotech must refrain from such false scientific statements. Therefore, it is truly important not to mislead people and scientists until Globe makes solid data from their preclinical studies with their vaccine candidate.
Does being enlisted on the WHO website as a candidate vaccine mean international approval or recognition?
The answer is No. The WHO has repeatedly mentioned a disclaimer in every page of the enlisting document: "Inclusion of any particular product or entity in any of these landscape documents does not constitute, and shall not be deemed or construed as, any approval or endorsement by the WHO of such product or entity (or any of its businesses or activities). While the WHO takes reasonable steps to verify the accuracy of the information presented in these landscape documents (i.e. only a few info- vaccine type, company name, county of origin, dose and stage of development), the WHO does not make any (and hereby disclaims all) representations and warranties regarding the accuracy, completeness, fitness for a particular purpose (including any of the aforementioned purposes), quality, safety, efficacy, merchantability and/or non-infringement of any information provided in these landscape documents and/or of any of the products referenced therein."
Covid-19 vaccine development is monitored internationally. If something goes wrong in human trials, the hard-earned reputation of Bangladeshi pharmaceutical companies exporting generic drugs worth over $130 million per year could be at stake.
Therefore, the regulatory authority of Bangladesh must seek expert opinions from reputed international regulatory agencies for ensuring the quality and safety of BANCOVID-19 before giving its approval for human clinical trials.
Globe Biotech Limited is developing the Covid-19 vaccine candidate for human use and obviously not for mice. Globe cannot start human trials just from some basic in vitro and mice studies due to poor quality of the data.
It is also unacceptable and could be dangerous that Globe Biotech attracts public by the media using false scientific statements, for instance, mentioning the Th1 response which is not even induced by their vaccine candidate. We should realise that the preprint manuscript of Globe Biotech is not just an academic manuscript, but it involves human health and safety if they want to pursue Phase I clinical trial.
Therefore, Globe Biotech must follow the international guidelines for vaccine development including those of the WHO, the ICH, the EMA and the FDA. The Bangladesh government's regulatory authority, namely the Directorate General of Drug Administration (DGDA), must ensure that Globe Biotech strictly meets those international guidelines to be able to start human trials to safeguard the people of our country.
Ensuring the health and safety of the people is the crucial responsibility of the government of any country and we hope that the Bangladesh government will set international standards to be proud of.
Dr Rezaul Karim is an immunologist and former project lead at WHO-Utrecht Centre of Excellence for Affordable Biotherapeutics, the Netherlands.
Dr Jubayer Rahman is an immunologist working at the National Institutes of Health, USA.
Dr M Shamsul Alam is an immunologist working at the National Institutes of Health, USA.
Dr Mohammad Sorowar Hossain is the former senior manager (R&D) of Biotech Division at Incepta Pharmaceutical Ltd; Associate Professor, Independent University, Bangladesh; and Executive Director, Biomedical Research Foundation, Bangladesh
Professor Dr Md Anwar Hossain is the vice-chancellor of Jashore University of Science and Technology and a vaccine development researcher.