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Vaccine hesitancy, efficacy and rollout

Controversy and misinformation have thwarted the effort of governments around the world in rolling out COVID-19 vaccination programmes. Shrikant Peters, a medical doctor, dispels some of the myths by explaining the process in approving vaccines for safe use. He argues that participation in the vaccination drive contributes to the common good.

With 2020 behind us, the novel coronavirus is seemingly novel no longer. In 2021, global attention has turned to the process of mass vaccination to vanquish the worst pandemic in over a century. Governments around the world are hoping to end the health and economic disaster of the past 12 months by achieving herd immunity – a state in which at least 70% of the population is no longer susceptible to COVID-19, and community spread is contained.

Scientists have completed trials on several vaccine candidates, which have proven to be safe and effective in preventing COVID-19, and are now available commercially. Many countries have already bought large consignments and are conducting widescale vaccine drives to administer these to their citizens. Vaccine hesitancy (the delay or outright refusal to accept vaccination despite its availability), alongside logistic and economic constraints, threatens the ability of governments to achieve herd immunity and end the pandemic.

Hesitancy

At a populational health level, the aim of vaccination programmes is to establish “herd immunity”; the individual protection that results from a certain sub-minimum of the population being immune to an infection. Once this is reached, long chains of transmission are interrupted, and infections can no longer be spread from person to person unchecked. This effectively prevents infections and small outbreaks turning into epidemics. This, however, relies on both high vaccine efficacy and low vaccine hesitancy.

Vaccine hesitancy is, therefore, a serious threat to herd immunity for government and scientific authorities to understand and confront. Hesitancy can include a range of different behaviours, from the purposeful delay of receiving vaccination, to an aversion in receiving certain vaccines or the complete refusal of all vaccines. In modern democracies, vaccination is voluntary. The compulsory administration of a vaccine to someone who is of sound mind who does not wish to receive it, is classified as an act of assault.

Vaccine hesitancy is a serious threat to herd immunity for government and scientific authorities to understand and confront.

Fundamentally, vaccine hesitancy is driven by a lack of trust in the process, people or systems involved in developing and administering vaccines. This lack of trust may or may not be solely related to the physical properties of the vaccine itself, but may also be informed by one’s prior relationship with science, the medical fraternity, the health sector and government at large. Certain communities and leaders may also forbid or deter the use of vaccines and medications on moral or ideological grounds.

Individuals will take all of these elements into consideration in their assessment of the perceived risks and benefits of vaccines and drugs, and will then choose accordingly. According to two studies conducted by the World Economic Forum and the University of Johannesburg, about two-thirds of South Africans have indicated their willingness to be vaccinated. This is lower than the three-quarters of adults globally. To achieve herd immunity with the current AstraZeneca vaccine (with an efficacy of 60-70%), more than 86% of the population would need to be vaccinated.

Safety and efficacy

The first trials (Phase I) that are performed for any drug or vaccine are small-scale and simply attempt to establish the side effect profile and frequencies of the different doses administered. If serious adverse effects occur, vaccine development is halted, and these are further investigated.

Once safety has been proven, vaccine development moves to Phase II trials, which aim to prove efficacy in a small group of people. Study participants (volunteers) are inoculated with antigenic material, which mimics the targeted virus. Follow up tests determine whether the volunteers have developed an immune response (innate protection against infection), what side effects they experienced, whether they became infected with coronavirus and if so, the level of severity.

In Phase III, the vaccine is administered to larger groups of diverse ages, ethnicities and co-morbidities, while still assessing for both efficacy and safety. To quantify the amount of protection achieved, those who receive the vaccine are followed up together with a control group who have not been vaccinated. 

Once Phase III trials are concluded, vaccine manufacturers apply to governmental agencies to have the drug registered for sale and use within countries. Examples include the Food and Drug Administration in the USA, and the South African Health Products Regulatory Authority (SAPHRA) in South Africa. All commercially available vaccines are thus guaranteed to have a safety and efficacy profile that have proven benefits and minimal risks.

ReadVaccines and immunization: What is vaccination? 31 December 2020 // World Health Organization

Multiple vaccines have been developed simultaneously and are now being rolled out globally. In the last week, SAPHRA approved the use of the first COVID-19 vaccine to be administered in South Africa, from AstraZeneca. The government has purchased 1.5 million doses of this vaccine from the Serum Institute of India, which has been reserved for use in healthcare workers countrywide.

There are multiple types of vaccines, which use different technologies with the same aim – to introduce COVID-19-similar antigenic material to which the body will respond. These different candidates have different efficacies, but also require different logistic support for rollout.

The Moderna and Pfizer-BioNTech vaccines have shown approximately 95% efficacy, but require freezer storage at -20 and -70 degrees respectively, with two doses two weeks apart. This makes them difficult, if not impossible to administer in various developing nations that are unable to maintain cold chain supply networks. Others include Sinopharm (80% efficacy, 2-8 degree refrigeration, 2 doses), Gamaleya (90% efficacy, -20 degree refrigeration, 2 doses), Johnson & Johnson (90%, 2-8 degree refrigeration, 1 dose) and the Oxford AstraZeneca vaccine (60-70% efficacy, 2-8 degree refrigeration, 1 dose). Prices differ according to efficacy.

Early indications … suggest that newer mutations of the virus have developed morphologically different external proteins … resulting in lower levels of vaccine efficacy.

Complicating matters further, the data above refers to vaccine efficacy against earlier strains of COVID-19. The new strains were not included in earlier trials. Worryingly, early indications from current trials suggest that newer mutations of the virus (such as 501Y.V2 in South Africa) have developed morphologically different external proteins that demonstrate “vaccine escape”, resulting in lower levels of vaccine efficacy.  

This also increases the risk of re-infection for people infected with older strains of the virus. Despite this, vaccine efficacy in early data is still around 60%, and vaccination is still presumed to decrease the severity of the disease for new strains of the virus. Ultimately, local vaccine production will be required to overcome local strain mutations.

Rollout

The first batch of Astra-Zeneca vaccines arrived in South Africa on 1 February 2021, with vaccinations of healthcare workers starting in health facilities and other designated locations from 15 February. These were purchased from the Serum Institute of India and are the result of negotiations that started in January of 2021, seemingly due to public pressure.

Prior to this, South Africa signed up to the global COVAX facility, which is aimed at ensuring equitable access to vaccines by country cross-subsidisation. The aim of the initiative is to ensure that all countries vaccinate at least 20% of their population, including frontline healthcare workers and those most vulnerable to severe COVID-19 illness, complications and death.

The South African rollout plan is divided into three phases: phase 1 focuses on bilateral procurement and administration to frontline healthcare workers at healthcare facilities (both public and private) while doses are limited; phase 2, which makes greater use of a larger supply from the COVAX facility to people aged 60 and above and adults with co-morbidities; and lastly phase 3 targets all adults older than 18. Having been prepaid for by government (likely via increased taxes), these will be administered for free at the point of purchase.

The aim of the initiative is to ensure that all countries vaccinate at least 20% of their population.

With the overarching plan communicated to citizens and provinces, the task now falls to individual facilities to prepare their staff, equipment and services to rapidly escalate their capacity for large scale vaccination drives over the next month. This will require logistical support from provinces, private companies and other government departments. Due to delays in procuring stock in sufficient quantities to complete phase 2 and phase 3, we must also prepare to endure further waves of COVID-19 infections as well as further disruptions to competing healthcare services, which may be of unpredictable size and duration for at least the rest of the year.

The argument for vaccination

President Cyril Ramaphosa, in his 1 February “family meeting”, reiterated that nobody would be vaccinated against their will and that vaccinations would not be carried out in secret or under false pretenses. The president placed the onus of responsibility on each citizen but cautioned against the spread of fake news and alarmist reporting around the vaccination rollout.

The evidence provided here shows that the medical fraternity applied due diligence in testing the various vaccines that have now come onto the market, as it would for any vaccination protocol. The South African government similarly has procured vaccines from reputable suppliers and is making these freely available to citizens.

While there will always be a small minority of people who will react badly to the vaccine, as with any medication, there is a strong argument to be made for receiving the vaccine and participating in generating and maintain the common good, that is, “population immunity” as President Ramaphosa described it. This ultimately will allow life and commerce to resume in full swing.

* The opinions expressed here by Spotlight.Africa contributors and editors are their own and not official statements of the Society of Jesus in South Africa or of the Catholic Church unless explicitly stated.