Shabir Madhi, Principal Investigator, SA Ox1_nCoV VIDA Vaccine Trial
“Limited community engagement on COVID-19 response – a pitfall in SA’s response to COVID-19”.
Moderator: Tian Johnson
Complied by: Anna Matendawafa – with inputs from Wilfred Gurupira & Maaza Seyoum
Queries?: info@africanalliance.org.za
Webinar Recordings & Supplementary Materials:
Date: 16 July 2020
WHO
Shabir Madhi is Professor of Vaccinology at the University of the Witwatersrand, Johannesburg, South Africa; and co-founder and co-Director of the African Leadership Initiative for Vaccinology Expertise (ALIVE). Professor Madhi completed his undergraduate and postgraduate training at the University of the Witwatersrand, qualifying as paediatrician in 1996 and obtaining his PhD in 2003. He currently also holds the positions of Director of the South African Medical Research Council Respiratory and Meningeal Pathogens Research Unit and Research Chair in Vaccine Preventable Diseases of Department of Science and Technology/National Research Foundation. He served as the immediate-past Director of the National Institute for Communicable Diseases (2011-2017), and currently serves as the Chair of the National Advisory Group on Immunisations in South Africa. He has co-authored over 400 scientific publications between 1997 and 2018 and has supervised 19 PhD students. His research has focused on the epidemiology, and clinical development of life-saving vaccines against pneumonia and diarrheal disease.
More recently he has focussed on vaccines being developed for immunisation of pregnant women for the benefit of the women and their young infants. His research has been pivotal for informing World Health Organisation recommendations on the use of the lifesaving pneumococcal conjugate vaccine, rotavirus vaccine and influenza vaccination of pregnant women. Scientific recognition of his research include receiving the European Society for Infectious Diseases Young Investigators Award (2006), National Science and Technology Forum: TW Kambule Award (2009), National Research Foundations President’s Award: Transformation of the Science Cohort (2010), Medical Research Council LifeTime Award (Platinum medal; 2013), and the European & Developing Countries Clinical Trial Partnership award for Scientific Leadership (2016). He is an elected member of the Academy of Science of South Africa (2012), Royal Society of South Africa (2016) and Fellow of The World Academy of Sciences (2017). He is also recognised as an A-rated scientist by the National Research Foundation since 2012.
WHAT
The trial intends to find out if a vaccine called VIDA (overseas it is called the Oxford Vaccine) used to prevent COVID-19 is safe. Because of South Africa’s large population of people with HIV, the study is looking at both HIV – and HIV + people between 18 and 65 years old. Some of the people who take part in the trial will be injected in the arm with a salt water solution and the rest will receive the vaccine. This will help researchers see if there is any difference in getting COVID-19 between those who received the salt water and those who got the potential vaccine.
WHY
All evidence – in South Africa and around the world – points to the fact that the COVID-19 pandemic will not disappear with the change of season or at the end of the year. In fact, it is likely that we will experience multiple outbreaks of SARS-CoV-2 (also called waves) over the next two to three years. It is becoming increasingly clear that our global economy and collective mental health cannot withstand an indefinite lockdown. Therefore, a safe and effective vaccine is our best hope for returning to something resembling normal life. It is critical that South Africa – and the African continent as a whole – be involved in COVID-19 vaccine research. We know that vaccines do not necessarily work in exactly the same way across different populations. Historically, some vaccines have been shown to work very well (highly efficacious) in Western Europe and North America but then found to work much less (less efficacious) – and, at times, not work at all – when evaluated in low and middle income settings. This has meant that Africa has had to wait – in some cases for over a decade – to have access to critical and life-saving vaccines and therapeutics that were already available in other countries. According to official figures, South Africa is currently experiencing the greatest burden of COVID-19 on the continent. For this reason, it is even more important that South African communities and researchers be involved in the early stages of vaccine trials, in order to be in a position to generate data applicable to the local context.
HOW
A total of 2000 participants will be enrolled into the trial; 1950 HIV-uninfected and 50 people living with HIV. Participants will be followed up for 12 months after enrolment.
WHEN
Actual Start Date : 24th June 2020 Estimated Primary Completion Date : October 2020 Estimated Study Completion Date : December 2021
WHERE
RECRUITING
Soweto Clinical Trials Centre ,Johannesburg, GautengWits RHI Shandukani Research Centre, Johannesburg , Gauteng Setshaba Research Centre (SRC), Soshanguve, GautengChris Hani Baragwanath Academic Hospital, Soweto, GautengGroote Schuur hospital, Lung Infection and Immunity Unit, UCT, Cape Town ,Western Cape
NOT YET RECRUITING
PHRU Kliptown, Johannesburg, Gauteng
FAMCRU Cape Town, Western Cape
QUESTIONS AND ANSWERS
*This section contains a transcribed account of the Question and Answer Session with inputs provided in writing after the call to questions that were not addressed during the call.
TRIAL FUNDING Please elaborate on the funding mechanism of the trial – who is contributing and how much are they contributing?
The University of Oxford is providing us with the vaccine at no cost, as part of an agreement with Wits Health Consortium, at the University of the Witwatersrand. The funders of the study are the South African Medical Research Council and the Bill and Melinda Gates Foundation, following a grant application submitted by myself to The Bill and Melinda Gates Foundation. The BMGF did not volunteer to fund us on their own accord, and the same goes for the South African Medical Research Council. It’s after I managed to get University of Oxford to agree to at least to provide us with the vaccine and they indicated that I would need to look for funding that I went around looking for funding. There were other groups that we actually approached as well for funding including a number of different embassies. The SAMRC and the Department of Science and Technology have been able to raise R10 million, the Bill and Melinda Gates Foundation have awarded us with a grant valued at R130 million. Usually these studies are much more expensive than what I’m actually indicating so we have needed to really scale back on a number of components. There is absolutely no profit derived from any of the sites in terms of the participation on the study.
BROADER STAKEHOLDER ENGAGEMENTCan you give an overview of the community engagement strategy for this trial?
All sites partaking in the trial have engagement with community advisory boards (CABs) that have been established over the past few years. The site principal investigators met with their respective CABs prior to trial initiation at their sites to discuss the Ox1 nCoV-19 trial and share relevant information about the trial, the anticipated benefits and risks to participants and communities of COVID-19 disease and the vaccine trial and request support from the community for the trial.
How can we as civil society contribute to ensure accountability and rigor in the research process?
In terms of community engagements I fully agree that this is essential, in terms of the research we conducting, as well as more broadly with our response to COVID-19. The limited community engagement on COVID-19 response, is a pitfall in terms of South Africa’s response to COVID-19 crisis. This is exemplified by not having engaged with behavioural scientists at an early stage, because what we are experiencing now in terms of non-adherence to non-pharmaceutical interventions is because scientists are not great in terms of getting messaging out to the communities. We need other categories of skill to be able to assist in that process. I don’t think it’s unique for a clinical trial. It’s something that is much more general to COVID-19.
What is the community engagement plan for this trial apart from the site CABs ?
People still don’t have a good understanding in terms of the virus, what their risk is, how even when they are not at risk of severe disease, they still pose a risk to others by being reckless to not adhering to non-pharmaceutical interventions. So although we have engaged with the community advisory boards (CAB’s), I don’t think it’s adequate as It represents a certain group of people. But at the same time we need to understand that any delay in terms of clinical development of a vaccine of therapeutics is putting lives on the line, and the pandemic is not going to wait for us to check all of our boxes before we move ahead. So it’s a balance in terms of risk and benefit and right now there is a clear benefit to bringing this pandemic under control not just in South Africa but globally. COVID-19 is impacting our people, including possibly excess death from non-COVID-19 diseases, and it’s also destroying economies which are likely to take five to ten years to recover.
If scientists generally have a problem with engaging communities, what is Shabir’s approach to addressing that?
It can’t be business as usual, but that’s not an excuse not to engage with communities. Somehow we need to develop the structures where we getting different groups within different expertise to assist in terms of that engagement. Like I said, unfortunately I don’t think scientists such as myself are very good at that.
DSMB COMPOSITION Where is the DSMB for the trial sitting and what’s SA’s representation there?
The DSMB is made up of people mainly from the United Kingdom, and included one person each from Kenya and South Africa (Prof Gregory Hussey from UCT).
CAB COMPOSITION Is there an SA CAB for this study and who sits on it?
There isn’t a CAB dedicated only to this trial. Each of the participating sites have CAB that they engage with, but more broadly than this study.
ASTRA ZENECA’S INVOLVEMENT
What is the current relationship, if any, between the University of the Witwatersrand and Astra Zeneca?
The University of the Witwatersrand does not have a direct relationship with Astra Zeneca for this trial, however, the University of Oxford, which is providing vaccine to the trial at no cost to the South African teams, has an agreement with AZ to manufacture the IP.
What is the exact nature of Astra Zeneca’s involvement in this trial?
The agreement between Oxford University and Astra Zeneca followed after my agreement with University of Oxford for them to provide us with the vaccine. So this particular study is in no way under the stewardship of Astra Zeneca. AZ has got observer’s status in terms of hearing what’s happening with the study because they are observers on the DSMB, but they don’t play any role in the South African study. They do play a role in terms of the study in Brazil and the study planned in the United States.
What commitments, if any, has Astra Zeneca made to the trial leadership and the governments of countries where this trial is happening?
The agreement between the University of Oxford and Astra Zeneca in terms of the IP rights around the study is multiple but the key part of it is that at least during the pandemic period that this vaccine will be made available at the cost of production, which basically means at no profit for Astra Zeneca at least for a period of duration of the pandemic. In addition to which Astra Zeneca is also partnering with other manufacturers in low & middle income countries specifically with Serum Institute in India for them to produce this vaccine; because there is no company in the world that is going to set up a facility to produce billions of doses of vaccines for two years and these facilities become white elephants because you probably going to need millions of doses moving forward.
The entire model around which these vaccines are going to be produced is really being dealt with at multiple fronts. There is an initiative by GAVI(Global Alliance for Vaccines & Immunisation) together with CEPI (Coalition for Epidemic Preparedness Innovations) known as COVAX that will enable governments to be able to secure procurement of vaccines with an advanced market commitment framework. The COVAX initiative has started as of last week and South Africa has already put its head up in terms of wanting to access to vaccines through that particular initiative.
TRIAL SPECIFICATIONS Please share some of your reflections on the participant recruitment process so far.
Recruitment into the trial varies slightly between sites. Recruitment strategies at sites have included:
·Utilisation of databases available in the research units which contain contact details of participants or parents of participants in previous (completed) vaccine trials.
·Adverts approved by the local ethics committee may be utilised and posters in health care clinics and other public places.
·Radio announcements
·Community engagement via the community action boards affiliated to the research sites
The community of South Africa has expressed great interest in the COVID-19 vaccine trial, and people from all walks of life have been screened for and enrolled into the trial.
How was the age group selected for the trial? What was the criteria for age selection?
Initially we had planned on doing 18-55 of age and then after SAHPRA and Ethics reviewed they actually advised us to revise it up to 65 years of age. The reason why we limited to this group is that 18 years is the cut-off legal age to be able to consent for participation in the study; and we know that COVID-19 is disproportionately affecting adults compared to young children, so it is essential that we first figure out something for the adult population. The reason for having the upper limit of 65 years of age is that older individuals may have even greater comorbidities that could interfere with their immune responses. The vaccine is, however, being evaluated in people older than 70 years in the United Kingdom. For South Africa, as a proof of principle, we want to target an age group where we are hoping the vaccines will work and who constitute the majority of the adult population in any case.
Can you share a race and gender breakdown of participants so far?
Of the first ~350 participants, just over 60% are male and the median age of participants is 30 years old. Approximately 92% are black, 7% white, and 1% other races.
We usually have access to vaccines or prevention methods in South Africa. How will accessibility work once this vaccine is available?
The South African government supports global access to effective COVID-19 vaccines. Once vaccine(s) are available, vaccine distribution will need to be strategised to ensure that priority groups, including healthcare workers and people at high risk of severe disease and death, receive vaccine first.
Please elaborate on the timeline: According to media report you have said that once 42 cases of COVID-19 have been identified in participants this will allow you to unblind the study and analyse the data to see if the vaccine works. How long do you anticipate it will take for us to get to that number of 42?
So it largely depends on how widespread the circulation of the virus is because if people are exposed to it more intensely over a shorter period of the time, the cases will accrue over a shorter period of time. Initially we estimated that we would need to go into 2021 before we there are that many cases of COVID-19 in the volunteers, however, unfortunately the amount of infection that is taking place in South Africa right now, indicates that we may be able to get an answer as to whether the vaccine protects against COVID-19 as early as the end of November 2020.
And then what from there?
Once 42 COVID-19 cases fulfilling criteria for analysis (COVID-19 cases that occur more than 14 days after vaccination) have been accrued in the trial, the trial statistician will conduct interim analysis of the trial data which will be presented to the Data Safety Monitoring Committee (DSMC). As the analysis requires unblinding of the data, only unblinded trial teams (statisticians, DSMC) will be able to receive and review data. The DSMC will review the data and assess if the vaccine has shown to be effective against preventing COVID-19 disease in vaccine recipients, compared to placebo recipients. The DSMC will make recommendations concerning continuation, modification or termination of the trial. If the vaccine is assessed to be effective, the DSMC may advise for any further enrolment to be halted, and to offer the active vaccine to placebo recipients.
The participants who tested positive for COVID – were they referred into care and what was that care?
All volunteers and trial participants who test positive for SARS-CoV-2 at any trial-related visit are informed of their results as soon as they are available. The trial team asks SARS-CoV-2 infected participants about their symptoms. All volunteers/participants are instructed to follow the regulations in place, which include isolation of patient and quarantine of close contacts. All volunteers (screened) and participants (enrolled) who test positive are reported to Notifiable Medical Conditions registry as per legal requirements.
If a volunteer tests positive for SARS-CoV-2 at screening, he/she is excluded from proceeding to trial enrolment.Trial Participants who are asymptomatic or mildly symptomatic are advised to isolate at home or an appropriate isolation facility. Participants who have severe disease are advised to seek care at their local hospital which has facilities to treat COVID-19 patients.All SARS-CoV-2 participants are followed up regularly (every 5-8 days) by trial team, who collect repeat swabs and bloods.
How much education is given to the volunteers as engagement and education should be central to the process?
Volunteers are fully informed about the trial at the screening and enrolment visits, as well as at any other time point during and after the trial.At the screening visit, trial teams verbally inform volunteers about the risks and benefits of partaking in the trial, procedures and responsibilities of both trials teams and participants. Volunteers are given two informed consent forms (ICFs) to read- screening and HIV & Hepatitis B testing ICFs. Once they have read the ICFs, they meet with a senior trial team member, and they have the opportunity to ask questions about the trial.
The team member will assess their understanding of the trial processes, and volunteer and trial team member will sign ICFs.If the volunteer fulfils inclusion criteria and none of the exclusion criteria, he/ she will be invited to return to the trial site 2-4 days after screening for enrolment. At the enrolment visit, a volunteer is given more in-depth details about the trial, and goes through another verbal information session. Another 2 ICFs (enrolment and storage) are given to participant to read, discuss with team members and sign. Volunteer also has to obtain at least 80% for a short test, the ‘assessment of understanding’ which is issued at the enrolment visit. Trial team members are fluent in most of the official languages, and ICFs have been translated into isiZulu, Sesotho, Setswana, Afrikaans and Xhosa and are available for participants. The in-depth education process that volunteers/ participants undergo is well described in a recent article by a participant.
Can you share some comments about accessibility post trial?
If the vaccine is proven to be safe and effective, placebo recipients will probably be offered early access to the vaccine.
?What are the challenges you are experiencing that impact the potential results of the study?
The COVID-19 pandemic has spread rapidly through the South African population, especially since level 5 lockdown was lifted. Asymptomatic disease has been reported globally. The extent of asymptomatic disease circulating in our communities was highlighted in the first weeks of trial enrolment, when more than 20% of volunteers for the trial tested positive for SARS-CoV-2 on nasal swab at trial screening/enrolment visits.
The primary analysis of the trial will only include participants who are negative for both current (nasal swab) and previous (presence of antibodies in blood) COVID-19 disease. The high prevalence of asymptomatic disease may impact the trial, by forcing the exclusion of many participants from primary analyses. This could necessitate the need to increase the number of participants needed on the trial, which will prolong the time until we have results available.
REGULATORY ISSUES
We are hearing about a lot of rush to do the COVID-19 trials with SAHPRA approving with speed as well. How is the rush balanced with rollout and access thinking for when and if the products are successful?
The speed by which these trials are implemented might suggest a compromise on ethical processes like informed consent that should be informed by adequate community engagement. We note this is a lacking feature given the speed.
So I think those are really important questions. I think we need to just clarify why SAHPRA has been able to fast track: that is because they put everything else in the back burner in terms of the other applications that were coming forward so it’s not to say their rigour in terms of the interrogations of the protocols and ethics and the science is any less.
All they have done is prioritised reviews of COVID-19 protocols and putting everything else on the back-burner, which has allowed them to free up time and space to get this done over relatively on a short period of time. But SAHPRA as an example did not actually approve our protocol on the first submission. The initial submission was on the 9th of May, and we only finally received the approval on the 15th of June, which was after responding to two rounds of comments from the reviewers, as well as changes they were requesting and the similarly so for with the Ethics committee submission. So, the SAHPRA review is not a mere ‘stamping’ process, but the trials are being subjected to interrogation in terms of the science and the ethics of its conduct.
Putting everything on the back burner suggests that HIV and TB trials are suffering on top of an already slow pace of SAHPRA’s responsiveness to research.
SAPHRA has been able to continue its work other than on COVID-19, however, the reality is that it has become complex to continue doing work on non-COVID projects in the current environment due to logistical issues. The main issue, is we cannot allow for management of people with TB and HIV to be compromised during these challenging times.
GOVERNMENT AND POLITICAL INVOLVEMENT What is the involvement of the SA government in this study?
The South African government is supportive of the trial, as the need for a vaccine is appreciated by all. The government, however, is not directly involved in the vaccine trial.
What has government’s interest beyond his interest in conducting the trials?
Government’s support of the COVID-19 vaccine and treatment trials has afforded South Africans’ access to newly-developed vaccines and treatments, many of which are in clinical trials. Rapid enrolment into trials globally assists in obtaining results quickly, which will benefit all Africans in the long term.
Do you get the sense that there is political will for this trial?
Yes, there is political will to find a way of preventing COVID-19 disease and reducing the impact that is having on the health of our population and economic stability of the country.
SHABIR’S MOTIVATION
What is Shabir’s motivation to reach out to do the trial and in what capacity as an African?How is his personal motivation and health outcomes linked with government’s interest in supporting research? Otherwise it becomes an individual interest as opposed to a national agenda which speaks to politics and political will.
My personal motivation stems from what I have been doing for the past 25 years. My greater contribution to science, and to the country and to Africa has been the work we have done on clinical development on vaccines against pneumonia and diarrheal disease in children. This included studies on the pneumococcal and rotavirus vaccine, which my unit was the first on the continent and among low and middle income countries to show that we could protect children from dying from pneumonia and diarrheal disease by vaccinating them. Those clinical trials were actually done in Soweto at my research unit over the past 25 years, and informed WHO policy, in terms of its introduction into public immunisation programs of low- and middle-income countries. Each year those two vaccines alone saves approximately 500,000 children: including 7,000 children in South Africa from dying. So, my motivation for being involved in vaccine science is driven by the recognition of the impact it’s had in terms of saving lives of children. What we are faced with now is a crisis which is amenable to being dealt with by vaccines as intervention to break the back of this pandemic. The reason I ended up with this study on a vaccine that was developed at the University of Oxford in the United Kingdom, is that I have known one of the principal investigators involved in that study for roughly about 24 years, and managed to convince him to include South Africa in the clinical development pathway of the vaccine.
Notably, many life saving vaccines have taken between five to 20 years from the time it becomes available in high income countries compared to when it becomes available in low-middle income countries including South Africa. The reason for this lag is because there often isn’t adequate information in terms of epidemiology , and evidence that those vaccines would work as well in our local context. So, we end up sort of playing catch up all the time, that after the vaccines have been around for five years that’s when we start doing the vaccine studies and then it takes another five years before we generate evidence to get it introduced into the country and into Africa. We need to short circuit that, we need to be right at the front of research to ensure that we do these studies at the same time when the studies are being done in the high income countries, not five years later, and certainly not after the pandemic has passed as happened with the swine flu vaccine in 2009. The swine flu pandemic vaccine only became available in South Africa after the pandemic had passed, partly because South Africa was simply not involved in the clinical development of the vaccine. We can’t afford for that to happen this time around, and over and over again in the future.
STATUS OF COVID-19 IN SOUTH AFRICA Are people dying with or of COVID 19 – and is it even ok to attribute these deaths to COVID?
This is a much more complex question than it sounds. The short answer is amongst the adults that are being diagnosed in the hospitals where we are testing, we are testing them because they are presenting with a clinical illness that is suggestive of COVID-19 and the deaths in those individuals is highly likely due to COVID-19. Then as an example in children, if a child is born prematurely (as an example a death that occurred in a newborn who was born to a mother that was infected with the virus), and the child died, but the child died from complications of the preterm delivery which had nothing to do with COVID. So the child died because of immature lungs which is very common in children born prematurely, but that child was being nursed by a mother who was infected and they tested the child and the child also tested positive. But that doesn’t mean the child died from COVID-19. The child died of something else and not from COVID. Nevertheless, the bottom line is from the majority of the adults that are tested when they are hospitalised have been tested because they are suspected as having a disease that is consistent with COVID-19 and those deaths are very likely to be COVID related.
STATUS OF COVID-19 AND VACCINE DEVELOPMENT ACROSS THE GLOBE What other current or upcoming vaccine or treatment trial gives you the most hope – apart from VIDA?
So I think in terms of vaccines, we hoping that other vaccines which have shown really good immune responses and ability to protect in animal model studies enter into Phase II and Phase III human trials soon. In particular there’s a vaccine known as AD26 COV2-S vaccine. The other gene based vaccines which are being evaluated in the US. I wasn’t too impressed with the immune responses after a single dose. In terms of therapeutics there is emerging work on monoclonal antibody, which is sort of a passive immunisation. But we don’t know whether it would actually work for people with severe diseases or whether it is something it would be used to prevent people from getting infected at least for four to six months. But in terms of therapeutics I don’t see anything that is standing out there as being the promising intervention right now other than what’s already available to us.
How does the current vaccine development process address the anticipated wave of outbreaks you have spoken about?
Numerous vaccines are being developed around the world, utilising different platforms and constructs. Historically, only about 10% of vaccines which enter clinical trials in humans eventually enter the market, having fulfilled safety, immunogenicity and efficacy requirements. To date, no vaccines for COVID-19 have been licensed for use. Once one or more vaccines are proven to be safe and effective in reducing COVID-19 disease, vaccine manufacturers will need to upscale to manufacture millions of doses already in demand globally. The COVID-19 pandemic is ongoing globally, with numerous waves anticipated to occur over the next few years. Roll out of licensed vaccines will, in time, reduce transmission of the virus in communities, by creating an enlarging pool of immune people, which will disrupt the virus’s spread. This is called herd immunity.
What about the reality that some countries like the UK and the US have pre paid for the vaccines. What is the use of studies if we won’t have access to the product?
Global access to licensed vaccines against COVID-19 is a hot topic at the moment, which is supported by key role-players, including the World Health Organisation (WHO), the Coalition for Epidemic Preparedness Innovations (CEPI), the International Finance Facility for Immunisation (IFFIm), Gavi, the Vaccine Alliance and numerous philanthropic organisations. At present, numerous donors are supporting vaccine manufacture efforts, however, vaccine development and manufacturing companies receiving funding are required to sign commitments to ‘provide the vaccines at a price affordable to low-income and middle-income countries’ (Yamey et al, Ensuring global access to COVID-19 vaccines, Lancet volume 395, May2, 2020 Published Online March 31, 2020 https://doi.org/10.1016/ S0140-6736(20)30763-7)
The Africa CDC held a meeting of African Union Ministers of Health in June 2020, to discuss Africa’s leadership on COVID-19 vaccine development and access. Strategies for securing sufficient vaccine supply and removing barriers to vaccine roll-out in African countries were tabled, and discussion is ongoing.(https://africacdc.org/news-item/covid-19-vaccine-development-and-access-virtual-conference/ )
Equitable access to vaccines requires governments to work together, to ensure that the allocation system for COVID-19 vaccines is fair. Realistically, once licensed vaccine(s) are available, the global demand is going to overwhelm the global manufacturing capacity, and each country will need to have a strategy in place to acquire and roll out vaccines. Prioritisation of certain people will be required (e.g. health care workers, populations at greatest risk of severe disease and death).The fact that Africa is partaking in vaccine trials is beneficial to Africans, as it may increase the chances of Africa being able to access vaccines early.
There are rumours that the virus has mutated. Is this true and how will the vaccine respond to mutations of the virus?
The SARS-CoV-2 virus, which causes COVID-19 disease is mutating slowly. Scientists around the world are sequencing SARS-CoV-2 isolated in different countries, and are able to follow mutations that are occurring. Approximately two changes per months (are being observed. It is unclear how these mutations, which are occurring at a low rate, would affect the transmissibility of the virus and severity of disease it causes.Vaccines in development are mainly based on the initial strains of SARS-CoV-2, but as the mutations are slow, they should still work well against mutated variants of the virus.
Also there is a study that showed that antibodies are reduced after three months, why do we have to think about herd immunity because we are not sure yet that those who have recovered won’t be infected in the future?
I think that’s really a very important comment. The antibodies appear to last for two to three months, but that doesn’t necessarily mean that there aren’t other components of the immune system that have been primed which could play a role in future immunity. A vaccine has got a number of advantages over a natural infection in that you are basically giving a much more control amount of the antigen, you are enhancing the ability of the immune system to respond to those antigens and you are likely able to induce much longer lasting immunity as well as what we call memory responses. So although it is possible, we may not actually achieve herd immunity at any stage with natural infections, it makes it all the important to be able to have an effective vaccine or else this sort of outbreak could continue for years.
What is your opinion on the BCG revaccination vaccine trial?
I think it’s highly unlikely that the BCG study will be shown to protect against COVID-19. The initial analysis suggesting a protective effect was flawed in its analysis, and if the same analysis is now redone, it will probably show there is no association between BCG vaccine coverage and protection against COVID-19.