By Washington Samukange and Chancelar Kafere
The current global outbreak of the coronavirus disease (COVID-19) has resulted in over 80 000 deaths worldwide. There is no specific treatment, outside of supportive care, that has proven effective against COVID-19.
Specific medicines for the treatment of this disease are being investigated, with the most promising of those being anti-virals, chloroquine, vaccines, and recombinant human angiotensin-converting enzyme 2. These will have to go through rigorous development and regulatory processes to ensure their safety and effectiveness before they can be available for routine use.
One potential treatment under investigation for COVID-19 is the transfusion of convalescent plasma collected from patients who have recovered from COVID-19 into those who are still affected.
Convalescent plasma is the straw-yellow liquid part of blood believed to be rich in antibodies against an infectious disease and is collected from a patient who has recovered from that infectious disease.
Treatment with convalescent plasma is a form of passive antibody therapy, which was first discovered in the 1890s. Back then, it was the only known means of treatment for certain infectious diseases.
Passive antibody therapy involves the administration of antibodies to an infectious disease agent to a susceptible individual to prevent or treat an infectious disease due to that infectious agent. Passive antibody administration provides immediate immunity to susceptible persons and subsequently, immunity for highly immuno-compromised patients.
Convalescent plasma contains neutralising antibodies relevant to the virus and these mediate protection through viral neutralisation.
It is possible that convalescent plasma collected from recovered COVID-19 patients contains antibodies to SARS-CoV-2 (the virus that causes COVID-19) and might be effective against the infection.
Convalescent plasma or immunoglobulins have been used to improve the survival rate of patients in previous outbreaks of other respiratory infections including the 2009 – 2010 influenza A H1N1 virus pandemic, 2003 SARS-CoV-1 epidemic and the 2012 MERS-CoV epidemic.
Moreover, several studies showed a shorter hospital stay and lower mortality in patients treated with convalescent plasma than those who were not treated with convalescent plasma.
Recent reports in the Proceedings of the National Academy of Sciences from China where COVID-19 convalescent plasma was used to treat a few critically ill patients indicate that it was effective as the patients recovered well.
These findings have led to scientists and researchers in several countries which include, Canada, Germany, Italy, Netherlands, UK, US, and Switzerland to initiate their own investigational use studies on convalescent plasma.
Addressing the current SARS-CoV-2 virus epidemic and the associated high mortality is an urgent health priority for any government. With the background knowledge that already exists on the concept of passive immunisation, the general possibility exists that application of convalescent plasma is effective in COVID-19 treatment.
This treatment option can be made available immediately as long as there are COVID-19 survivors capable of donating their plasma.
For this reason, it is prudent for the Zimbabwean government to urgently consider the use of convalescent plasma as a potential treatment option in response to this pandemic.
The Zimbabwean government needs to coordinate and organise a program to collect convalescent plasma from recovered COVID-19 patients. This convalescent plasma could provide a potentially valuable intervention in the interim, while data on effectiveness and safety of its use is obtained through an orderly scientific study.
The decision to pursue this option needs to be swift, to avoid any further potential loss of Zimbabwean lives. It is estimated that approximately 80% of people infected by COVID-19 develop only mild symptoms and recover fully without the need for special medical attention.
As more individuals contract COVID-19 and recover, the number of potential donors will continue to increase.
The Zimbabwean government must mobilise its health systems and infrastructure to obtain the best possible outcome for patients, with this candidate therapy.
The National Blood Services of Zimbabwe (NBSZ), the Medicines Control Authority of Zimbabwe (MCAZ) and the Medical Research Council of Zimbabwe (MRCZ), among other national institutions, will need to coordinate a COVID-19 convalescent plasma program with local treatment facilities.
Clinical use of convalescent plasma for this novel viral infection will be used as an investigational treatment option under controlled study conditions following national regulations.
Clinicians should spearhead the program and should naturally come up with a study protocol that meets ethical requirements from MRCZ and local Institutional Review Boards as well as clinical trial requirements from the MCAZ.
The NBS can manage the collection of convalescent plasma from recovered COVID-19 patients that contains SARS-CoV-2 specific antibodies at their facilities.
Collection of convalescent plasma in the country should be relatively easy, as the process is like normal blood collections except that in this case special donors are required. The NBS, which already has expertise in blood donor mobilisation and blood collection, should be responsible for the collection and processing of convalescent plasma.
Existing operational policies, standards and procedures governing blood transfusion in Zimbabwe must be observed to ensure the quality and safety. Only voluntary COVID-19 survivors meeting the existing national criteria for blood donation should be allowed to donate plasma.
Public awareness campaigns can be conducted to make correct information readily available in the country.
Transfusion-based treatment generally not risky for patients, but there is need to take precautions, if this is going to work for Zimbabwe. Where this convalescent plasma for COVID-19 has been used, it has not been a randomised clinical trial and the patients have received other treatment options such as anti-virals which are also under investigation for treatment of COVID-19.
Other considerations which will need the Ministry of Health to lead are, the NBSZ will need capacity to be able to check for absence of SARS-CoV-2 in recovered patients, as recommended by the International Society for Blood Transfusion (ISBT). To do this, they will need advanced testing instruments and reagents that detect the viral nucleic acid (SARS-CoV-2).
This is already a challenge, considering the total number of tests carried out to detect SARS-CoV-2 in Zimbabwe since the outbreak began. Further, the NBSZ will need further technical support to check for total and neutralising antibody titres in the collected convalescent plasma.
Use of convalescent plasma for treatment of infectious diseases isn’t a new discovery. It is an old-school method that is readily available with the right planning and foresight. This could help prevent further unnecessary loss of Zimbabwean lives.
Washington Samukange is an international regulatory science expert, microbiologist and regulatory systems analyst working on blood and blood product regulatory systems in Africa and globally at the Paul Ehrlich Institut (PEI), an institution of the Ministry of Health in the Federal Republic of Germany. He is passionate about strong regulatory systems and improved access and availability of medicines. Washington writes in his personal capacity. The views expressed in this piece are his own and should neither be read as nor attributed to the PEI. Twitter: @iamtendekai
Chancelar Kafere holds a Master`s Degree (MSc) in Strategic Quality Management from the University of Portsmouth (UK) and a Bachelor of Science in Medical Laboratory Sciences from the University of Zimbabwe. He is a Scientific Officer at the Paul-Ehrlich-Institut, in Langen, Germany where he works in the Global Health Protection Programme BloodTrain Project where he is responsible for assessing blood regulatory systems, and capacity building in the development and implementation of these in Africa. Prior to joining PEI, he was the Safety, Health, Environment and Quality Manager for National Blood Service Zimbabwe (NBSZ) as a Medical Laboratory Scientist. Twitter @KafereC